8p448.Low.back.Disorders.evidenceBased.prevention.and.Rehabilitation.t8x

1O\V ]3AC]( Get the latest informaton on evdence-based pevention and rehabtaton approaches om an nternatonay recognzed expert and ean how to apply the principles n ndustry, spot and everyday settings . . Low Bk Dordr: Evd-Bd Prvo d Rhblo provides poessonas wth the oundation to make the best clincal decsons for buildng the best prevention and ehabiltation pogams. The author's unique research resuts quantify forces that speciic movements and execses mpose on the ow back The text identfes commonly pescrbed pactices that ae, in fact, contraindcated in promoting back health. Additionaly, t povides appopiate stategies to ofset injures and estoe function Low Bk Dordr wil buid your undestandng of the scence behind the pactices so that you can use them effectivey wth clients and patients. The book pesents a cear exposition o back anatomy and bomechanics It also povdes the evdence to dspel myths egadng spine stabilization execise and varous peventon appoaches Fo exampe th e quantifcaton o stabity will show which musces are mpotant and whch exercses goove moto patterns to ensure spine stabty. With Low Bk Dordr, you will • gan vauable informaton on measued loading of the back during specific activites and apply t to avoid commonbut counterproductivepractices in back rehab; • earn how to analyze patients and cients' unique physical charactestcs and festyle needs actos and tao treatments and preventve measures to thei indvdual • lean how to help patents and clents achieve the ow back stabty requred to pevent utue damage and • acquire the nfomation necessary to pescrbe efective execises cealy and easily Low Bk Dordrs wel oganized and easy to undestand. Pat I provdes a sod foundation on how the back works and how the back becomes inued. Pat II shows you how to use ths oundaton to bud evidence-based preventon programs by assessi�g rsks creating ergonomic inteventions and trainng pesonnel Pat III focuses n mprovng ehabitaton technques and, speccaly quantication of spine stablity to determine which execses ae impotant for spne stabty for each person

ISBN 0-73604215

90000

Human Kinetics

9 7

Low Back Disorders Evidence-Based Prevention and Rehabilitation Stuart McGill, PhD

University of Waterloo Canada

Human Kinetcs

Lbray of Congress Catalgig-n-Publ .n Daa •

McG. Sart 1957ow ak disodes  evidece-ba�ed peveion ad reabtation I Sa McG p. : m Includ bbliographial reerence  and index SBN 7642415 (ad cove 1 Backae 2 Evdenebased medicine DM . Back njrs-previon&cotro 2 Back juihabilitation 3 Eidece-Based Mediine 4 Low Back Pan--previon&oro 5 Low Back ain--reabltaon WE 755 M477 22  Te RD77B27 M2 22 225695 675'6452-dc2 B -76-424-5 oygh © 22 by Sa McGill All rg  eeved Exept fo ue in a rview te epodtion or tiliation o ts wok  any fom o by any elonc mhana or othr ma  ow kow or ereafter invened. ncluding xergrapy photoopyg and recoding and i ay infomatio age and retieva sysem b orbidden wtho e win  ion of te pblih Aisitis Edto: oar  Rob!on P Devepmeta Edt: Eae H Muin: Assista Edtr Maggie Shwartra COycdior Pasy Foey Joorcade: n Cle Idexer Cig Brown ermissio1 Manage: aene Reeder Gaph Desige Fed Starbrd: Gaph Artit: Yvone Gi: Pht aagr i A Wm; Cer Desger: Jack W Dais: Coer Image Pimal Pictus; Photgrapher iterio: li A Woodrm excp were noed  Poto Cedits (pge 2) or on ddua photos: At MaUge Klly Hnd: s (): om Robs Istrat medial) Agosy Iiner: Serdan Boks

rned n h ned e of Ame

0  8 7  5 4 3 2

man Knets

Wb si wwwumnnom U"it Ss m ieti. PO Box 507, Campaign I 18255076 8-747457 -mi manhkum C" Hma Knec 475 vnhie Rad, Ut 1 Windo, O 8Y 25

8-465730  n Cda ony m d@kcnadcom Europ: Hma Kint 07 Bdrd Rad tngy d L A, Uited indm +44 (0 113 255 55 ·mi @hkum A m K 57A Avn. Lwer Mthm. Asa 52

08 8277 1555 ·mal k@nemau New 7alnd (m Kint PO  05-21. Acklnd Cenr]

09523-42 ma hk@ignz

I ddica his book o m ahs. M pans John an Elizabeh who bleved n th hap of had wok-i maks fo basing b a h nd of h da and a ee omoow Th fw high school achs who w abl o s as m ima tince an blligrn in paula Ralph Coluci who wihsoo m anis in his OY class bu hn spn ounlss hous coahing on h ak an fooball fils He acic h highs xampl of ail dicaion and h iv o ontinu afe ohs had givn up. hos lssons I will nv fog M unvesi pofessos in he ough al as paiulal D Klambau, who was abl o ansfom mahmaics fom absa magi ino somhing v mhanial hat I oul sudnl fl n m hands This was a uning poin Pofsso David Wine who augh m among man ohe hings, how o a a sinific pap Pofesso Robet Noman, m PhD supe viso and mno who is h mboimn of ingiy and h mas of viewing an issu fom h highs of inllual vanag poins M man sah olleaus fom around h wol, oo numous o mnion h, who hav augh m he man pspecvs nedd mp h aogan ha so nauall whensudns one is h onl pson pi o o nw sarh suls And o coms m wonful gaua Jacek Cholewicki Vanssa ingling ack Callaghan Slvain Gnie, Lina Sanaguia Csanto Sutao ohn Peach Caig Axle, Lisa Beon Gg hman, Jnnif Gun nn, Richad Puss, Joan Scannll David Beenik Kim Ross, Doug Richads, Kell Walk an Naasa Kavi h ol og has lan a fw of ou nw ricks. All of these pole hav oniud o m foging An maining psonal failings I an onl aiute o he unfouna combinaion of unning Canaian sofware on Iish hadwae Finall o m wife an chilen Kahn ohn an Saah, who hav augh m o s h o of h momn and njo h sui of unonional lov. 'm jus a chunk of oal bu I'm gonna b a diamond som da!

Contents

ist oTests and xecises xi Why and How You Should Read This Book xiii Acknowledgments xv

Scientific Foundation Chapter 1

Introduction to the Issues

1 3

egslative LandscapeThe Unfotunate Advese mpact on Bad Backs 4 Deficences in Cuent Low Back Disode Diagnostic ractces 5 I   True Tha % f Bac Truble Are f Unnn gy? 6 I  True Tha M hrnc Bac mplan Are Re n Pychgca Facr? 7 De Pain aue Acviy nlerance? 

nadequaces in Cuent Cae and evention of ow Back Disordes 8 I IAvie Rehabiain Recmmenan 9 an Bac Rehabiian Be mpl ee in 6  12 Wee?  hu he Pmay Ga  Rehaban Be Rer he Rae  M 2 Mechanical oading and the ocess of nuy: A ow Back issue nuy imer 1  A inal Note 1 5 Refeences 1 5

Chapter 2

Scientific Approach Unique to This Book

19

nVto ab 2 n-Vivo Lab 2  he Vrua  pne W 20 Devepmen  he Vrua pne 23

Refeences  Refeences and Bbliogaphy etaining to the ine Details of the Modeling ocess 

Chapte 3

Epidemiological Studies on Low Back Disorders (LBDs)

29

Multidimensional inks Among Biomechanical, sychosocial, and ersonal Vaiables 3 Three mpr an ue 30 D Wer perence BD Becaue They Are Pai  Ac Diable? 32 v

vi

Contents

Chapter 3

oiued

Multidimensonal inks Among Bomechanical, Psychosocia and Personal Vaiables (cant.) Doe Pain Have an Organc Ba-Or I I A n he Head? 33 Are Biomechanical Variabe and Pychoocial Varabe Din c? 35 Wha I he Sgnifcance of Fime Injuy Daa for aue and Pevenon? 36

How Do Bomechanica Factos Affect LBO? 36 Mechancal Loadng and LBD: eldBaed Rk Faco 36 Wha Ae he aing Phyoogcal, Biomechancal, and Moo ha nge o Which Injury Lead? 38 Wha  he Opimal Amoun of Loadng for a ealhy Spne? 38

What Ae the inks Between Pesona Factos and LBO? 40 What the Evidence Supports 4 Refeences 42

Chapter 4

Functional Anatomy of the Lumbar Spine

45

The Vetebae 45 Veebra Archecue and Load Beaing 7 Poeor Elemen of he Veebrae 5

Intevetebral Disc 53 LoadBea rng Abiie 5 Pogeve Dc nury 5

Muscles 58 Muce Size 58 Mucle Group 60 Abdomina Muce 68 Poa 72 Quadrau Lumborum 7 Muce Summary 75

Lgaments 75 ongiudna igamen 75 Inerpinou and Superpinou Lgamen 76 Oher gamen in he Thoracoumba Spne 78 Normal Lgamen Mechanc and Inuy Mechanc 78

umbodosal ascia (DF) 79 Clincally Reevant Aspects of Pain and Anatomic Stuctue 81 iueSpecifc Type of Pa n 82 an Pain Decpo Povde a Reliabe Dagnoi? 82

A nal Note 83 Refeences 83

Chapter 5

Normal and Injury Mechanics of the Lumbar Spine

Kinematc Propeties of the hoaco-umbar Spne 87 Kinetics and Nomal umba Spine Mechanics 92

87

Cotets



Sadg ad Bedg Forwad 92 oad o he Low Ba Dug fg 96 Load o he Low Ba Dug Wag 100 Load o he ow Ba Durg Sg 04 Load o he ow Ba Durg Flexo Exee 104 Load o he ow Ba Dug Exeo Exee 106

Dubious fting Mecanisms 1 08 raAbdoma eue 1 Lumbodora Faa 2 ydrau Ampfe 112 lA DF ad Hydrau Ampfe A Summary 13

e mpotant Mecanisms of Nomal Spine Mecanics 1 3 Bomeha of Dura Spe hage 3 Spa Memory 4 Aaomal Fexble Beam ad u Mule ooao ad Spe Sably

5

Injuy Mecanisms 1 6 Summary of Spef ue uy Meham 16 Ijury Meha og he umbar Meham 117

Biomecanical and ysiological Canges Following Injuy 28 ue Damage ahogee a  ad erfomae 29 Ijury oe Moo hage 129 Ohe hage 30

Refeences 1 31

Chaper 6

Lumbar Spine Stability: Myths and Realities

137

Stabilty: A Quatatve Analogy 1 38 Quanitative Foundation of Sability 39 oeal Eergy a a Fuo of egh 39 oeal Eergy a a Fuo of Sfe ad Ela Eegy Sorage 4 Suffe Sably 43

Stability Myts, acs, and Clinical mpcaions References

Chaper 7

143

1 46

Injury Prevention

LBO Risk Assessment

NS Appoac o Ris Assessmen 1 50 981 Gudele 5 9 93 Gudele 5

Snook sycopysical Appoac 1 52 umba Motion Monito (LMM) 1 53 4 WATBAK 1 53

147 149



Cntnts

Chapter 7

oiued

Bioogcal SignalDven Model Appoaches 1 56 h Maa Modl and h MGl Modl 156 MGAd Opmizaion 57 Simp r omplx Mdl? 157

he Chaenge Befoe Us 1 58 Refeences 58

Chapter 8 Reducing the Risk at Work Lessons om the iteatue 162

161

Ergnmi Sud 62 Rhab and Pvnion Sudi 62 Sudi on h onnon Bwn Fn and njuy Diabiy 163

BO evention fo Wokes 1 63 Should Wrkr Avod End Rang o Spin Moion Durng xrin? 164 Wha A h Way o Rdu h Raon Momn? 166 Shoud On Avoid Exrion mmdiay A Poongd Flxion? 70 Shoud nraAbdomna Pur (AP) B nad Wh ing 71 A Twing and Twing Li Paulary Dangou? 172  ing Smoohly and N Jking h Lad Alway B? 173  hr Any Way o Mak Sad Work  Dmanding on h Bak? 74 Som ShAnwr Quon 76

BO eventon fo Employes 1 78 njuy evention me 80 A Note fo Consultants 1 83 Refeences 1 8

Chapter 9

Reducing the Risk in Athletes: Guidelines

187

Reducing the Risk n Athletes 1 87 What Coaches Need to Know 92 Reeences 1 92

Chapter 10

The Question of Back Belts

ssues of the Back Bet Queston 94 Scientific Studies 1 94 lna ra 95 Bmhanial Sud 96 Sud o Bl a Ra and Blod Pru 98 Pyhphya Sud 9 9

Summay o escption Guidelines 1 99 Refeences 200

193

Cotet

Chaper 11

x

Low Back Rehabilitation

203

Building Better Rehabilitation Programs for ow Back njuries

205

inding th Bt Appoach 205 Stag of atint ogion 207 Sage . Awarene of Sne Poon an Muce onacon (Groovng Moon/Moor Paen) 20 Sage 2 Sabzaon Exece o Groove Sablzng Moor Paen an Bu Mucle Enurance 214 Sage 3. Enung Sablzng Moon Paen an Mucle Acvaon Pae rn ung All Acve 24 A Noe on Sof Tue reaen 25

Gudlin fo Dvopng th Bt xci Rgimn 25 eveong a Soun Ba fo Exece Pecon 25 Bac Iue n ow Bac Exece Pecron 26

Rfnc 221

Chaper 12

Evaluating the Patient

223

F Clinicanatin Mting 223 Spci T 225 Teng Mucle Enuance 225 Teng for Aberran Go Luba Moon 228 Teng fo ubar on Shea Saby 230 A Noe on Moon Paaon 232 Teng fo Aberan Moo Paern urng halenge Beahng 232 eernng Suaby fo ROM Tranng an Srechng 234 nguhng Bewe en Luba an H Pobe 236

Rfnc 238

Chaper 13

Developing the Exercise Program

239

liminay Ma 239 Phloohy of ow Bac k Exece Pecron 239 Sarng he Back Whe Srechng he  an Knee 240 Fong he Nerve Roo fo Thoe Wh Accoan yng Scaca 242

xci fo Taning h Stablizing Mucl 244 Wha Ae he Sablze of he Luba Toro? 244 Tranng he Sab le of he ubar S ne The "Bg Thee 244

Bginn' ogam fo Stablizaton 256 Rfnc 257

Chaper 14

Advanced Exercises

Safly ncang Chang 259 able Suface an Reance ranng Machne 259 Safely Progreng Bac  Exerce 263

259

x

Contents

Chapter 14

oiued

uptionl nd Atheti Wok dening 265 ow Back Exerce o HghPerfoance Woker or Ahlee 265 ow Back Exerce Ony o Ahee 268

ooking owrd 270 Refeenes 271 Epogue 273 Appendi 274 Photo Credts 280 Glossy 281 Inde 283 Aout the Author 295

List of Tests and Exercises

pag no.

Lateral Musculature Test

225

Fexor Endurance est

226

Back Extensors Test

226

pag no.

Side Brdge, Intermedate Varaton

252

Side Bridge, Advanced

252

Brddog, Remedial

254

Manua Testng for Lumbar Jont Shear Stabty

231

Brddog, Begnner's

254

Chalenged Breathng Test

233

Brddog, Intermedate

254

McKenze Posture Test Sittng Sump est

235 236

Brddog, Advanced Curl-Up, Highest Leve

255 263

Fajersztajn Test

236

Sde Brdge, Highest Leve

263

Hp Fexon and Rotation Tests

237

Birddog, Hghest Level

263

Flossng

243

Curl-Up, Begnners

246

Advanced xercses for Back Strength and ndurance

263

Isometrc xercises for the Neck

247

stablishng Spne Stablity When Breathng Is levated 266

Curl-Up, Intermedate

248

Tranng for Torsona Capacty

CurlUp, Advanced

248

Sde Brdge, Remeda

249

Sde Brdge, Begnner's

251

Sde Brdge, Intermediate

25

267

Speca Back Prescrption Those Whose Is Worsefor Wth Sittng and Then Have Trouble Standing 268 Star Exercses

269

xi

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Wy and How You Should Read Tis Book G

iven the myrad of stretch and strengthening programs avalable or the profes siona or layperson with a bad back, why wrte another book offering guide nes for better preventon and rehabiltaton of low back troubles? The reason is that ver few of the avaiable books/manuals actually quanti the demands of the exer cses specifcaly the resutng tissue loads and the muscle challenge. Ths has led to some programs recommending routnes that replicate the mechanical causes of the damage! Such routnes may actualy increase the rsk o deveoping back troubs or acerbate existng ones Other more specalzed books promote spne stablizaton exercises wthout uanting stability thus basing the recommnded exercses on a good guess-abeit a guess based on years of cncal obseaton  scientific founation to justi the recommendations has been thn at best. Tis book is not about peetuating clinical myth�it is about challenin them and proposing valid and jutable

alternative.

How the Book Is Organized The intention of ths book is to provde the best avaiabe scentfc evdence to opti mze inu prevention and rehabiitation eforts It is designed to assst thos who work to prevent low back troubes and those who are charged with the responsibiity of rehabitatng them Part I begins with a scan o the landscape reated to the ow back queston Here the main issues wil be introduced together with a bre ntroduc ton to the egislative and insttutonal constraints-some o which assst effos to enhance bak hea th whie others act as drect barriers . This is folowed with evdence as to how the ow back structure and associated tissues work during conditions o good health and how they become inured. These chapters describe •

how the spne works

•

nu mechansms nvoving individua tissues, and

•

nu mechansms nvoving the ll umbar mechansm

Specifc nformation-such as tissue oads muscle actvation eves and measures of stabity-s provided so that readers can meannglly compare approaches when decding how to prevent or rehabitate ow back nury Thus the irst pat provides the scientic oundation or the rest o the book Identing and mpementing the best pograms result rom considering the evidence Thus part II suppos evidencebased practce by appyng the scientic oundation in part I to the prevention of ow back in at III appes ths same nformation to th rehabitation o ow back inuy xii

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Low Back Dsorders

Focus and Features of the Text Ts text wll be of value fo tose volved  desgg ad deveg bac touble peveto ad eabltato pogamspyscal teapsts, pysatsts copac tos, esologsts egoomsts ad oopedc specalsts Lw Back Disrders eatues a umbe of elemets besdes te bas text to esue tat all segmets of te vey dvese eadesp tat deals wt low bac ssues wl be able to absob ad use te mateal Eac capte toducto cudes eag ob ectves Speca elemets  some captes ggt ssues of metodologcal co ce fo example o smply povde fue elucdato of some cocepts o tems tat ae ot commo acoss dscples veY secto tat as ccal elevace co tas glgted statemets detfed as suc I addto a wde vaety of occupa toal ad atletc exampes tougout te boo ca be geealed to al actvtes o day lvg A mao teme o ts boo s te beefts o bledg eabltato effots wt egoomcs ad peveto Tadtoaly, egoomsts ad dustal eees ave bee esposble o peveto efos maly  te woplace wle te medca commuty as bee esposble fo eabltato Ts atual dvso as caused a ufotuate compomse Reabltato effots wll ot be eectve wtout pe vetg te cause of te tssue tats, ad peveto effos wll be etaded wtout a udestadg of te vaables obtaed fom medcal vestgatos to te causes of tssue damage N clinician will be eecive  he cause f he paien's rubles is n remved Te expetse equed fo optmal peveto ad eabltato ca be foud  te felds of egoomcs ad eabtato medce, wc ae atually symbotc May  te spo ad busess wold ave debated wete t s bette to develop a stoge ofese o defese e obvous aswe s tat t s best to ave bot I opead tatsuccessul ts boo wl oste a bette pocess esutg  moe effectve uy peveto eabltato

Some Encouraging Words Some eades may be tempted to apply te mateal  pas I ad III wtout dgest g te oudato mateal cotaed  pat I Ts s a mstae eople wo ave atteded my couses ad wee pevously famla wt ou publsed scetfc papes ofte state tat tey wee uabe to fuly sytee te sto ad tegate te ctcal fomato Oce awae of te ul stoy cotaed  te couse ad tod  ts boo, tey wee muc moe efectve at pevetg ow bac dsodes ad pescb g execses tat ep patets become bette ate ta wose

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Note to Lay Readers Altoug ts boo was wtte fo clcas may lay people ave bougt copes fom ts tal pt u As a esult, tey ave wtte me lettes expessg te appecato o te bette udestadg te scece ad te ow bac toubles, ad may ave epoted substatal mpovemet Ts leads me to add te tougt tat atoug successu selfteatmet s gatyg t emoves some o te safeguads  te eabltato pocess If you ae a owe of a toubled bac ad ae ot a clca, I emd you always to cosult a pca at te outset to le Lt ay possbe exstece of a codto suc as a tumo o a cotadcato o execse

Acknowledgments

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 n  kn  fft nvv n tn  bk nt ty v n  v Mny pp v n p  t  I pfy n t tnk n kn y  t Hn Knt Pb: n Rn   y tn n n ptc En Mn f  xpt n t En n y  p cn n  cncp n g ptn n t tn t A Syvn Gn y PD unt n b n f t pptn f ny fg tt pp n t k

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Scientific Foundation

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he very best professionals with expertise in low back injury prevention and rehabilitation have two things in common: an insiht and wisom developed from experience and a stron cien tii foundation to enable evidence-based practice. Each problematic back is part of a whole person, who in turn is the sum of ifluences that rane from those at the cellular level to those at the societal level Some refer to this as the biopsychosocial approach No two problematic backs (or patients) are the same sgesting that optima intervention woul be different for each one The best aproach for optimal rehabilitation and prevention of those factors that exacer bate bad backs will reslt from wise and scientificaly ased deci sions Part I of this book provides a foundation for back professionals to enable them to make better decisions

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Introduction to the Issues

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r   g of mul d  offrg wdom o   lt Ar rg frm to w frml mdl r rl tr t lyl  v ud  r to llv tr w  trul  m lr md low b lt  rt. Tr tt r rl, ut r v  rrly d o  oud tf  udt  oo my  t tr fr rrt rmmdto or v rmul uggto. Yr    g t dv t vgt t vru t f lo  rol  ould  y grdu tud to fd t tf fudo r y of t "mm rmmto  w rg     d  drl ttg. o my urr y ot rortd tt  lrur yldd , r vry t, vd  t  oo my dt rly d t ty r vry omt d rl Exl o  tly urtd "omm rommd ld t fllg •

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 t  t rrm  tu B t  d  t  trg to rorm  lt Rdu t d g dld  ordr  rdu t r o  ru.

I ft  of t rmmdto my  rort  om tut t  wl  o   l. T m m J t Gr  wlw r dmtrtg tt to d  mmo wdm, t t  oom trm, r ft dod t fl .  td t omm wdom  g rlly tr omm r  Glrt loqutly xrd xtly wt I d xr wt " d rtg to t w  My tm t rvtg lw  trou d rltg ymtom  v d mly u ty rl o llvd ll wdm. T try  d ttmt  rly ufrut u t  l rd t  to o  mr of rgly wllw "utrt t lw  jury rvto d rlto rogrm r  wt f rr. T utor lm tt t mrty    rolm r ot rg t ll tt for xml mo of t dult v mtrzd u rr r

3

4

Low Back Disor ders

aid too mch fo injy comnsation hav n sjc to sychosocia nfncs o cav symathy Ths dsmissals of ac injy a no jstifid. a iny vntion and hataon ogams wth stong scintfic fondaions xtons and folow can  ffctiv. Havng satd ths I mst acnowdg tha jsyng movd acic on scin iic vidnc is a dynamic ocss Wth nw vdnc th fondaton wl chang  To accont fo sch invtal shifts I hav dvod a aancd aoach in hs ags vwing th assts and liais and oosng vws of an agmn wh aoa B fai waning As yo ad h s oo  a d to chaln cnt thoghs and thi n cunty accd acics of injy vnion and aoa chs o hailiaton This chat wl familiaiz yo wh som of th daal isss gading low ac ncion togth wth som onions that hailtaton ofssionas hold aot atnts dagnosis comnsaon and disaily It will also xlo h cicmstans hat lad to ac injy and disuss th nd to ay this nowldg  imv low ac ny vntion and hailitation

Legislative Landscape: Te Unfortunate Adverse Impact on Bad Backs Athogh most lgislation and lgal atty nvolvng ad acs a nact with good ntntons mch is contodciv A good xaml is h iss of sin ang of moion ROM. Th Amcan Mdca Associaton AMA gdlins 990) fo qantiyng th dg of ac disaily a asd mostly on oss f sin ROM Lawys and comnsaton oads who nd nms fo th os of dfining dsaily and wadng comnsation hav atchd ono sn ROM as an ojctiv and asily masd facto In h ga ana hay s consdd sssfl whn h ROM has n stod o a las imovd. cinific vidnc sggsts howv that aft ac injy, many ol do not do wl wih an mhasis on nhancn sin moliy n som cass ac lms a actally xacatd y his aoach In fact vdnc shows that many ac injis imov with stailizing aoachsmto contol tanng nhanmnt of msl ndanc and taning with th sin in a ntal osition aal and aa, 199 may  considd th classc wo O most cn wo has shown tha thdimnsional low ac an of moton has no colation to fnctional st scos o vn th aility to fom occaiona wo Pas t a in ss. In th st actic sin flxil iy may not  mhasizd ntil th v la sags of haiitaton if v How hn dd this ida of lxility as th st mas of sccssf haiitaion com so nnchd? Th cnt mic fo dminng disaity aas to hav n chosn fo ga convninc ath than fo a ostiv imact on ow ac ols Th cnt andsca cas a wad systm fo thay that agaly hnds otima hailitation has th citia fo dtmining disaility nd to  assssd and jstfid with scintfic vdnc Anoth xam illsats th vs mact of wlnndd qiy lgisaton W a hav qal ights nd h law t w a no hysia qas. Ahogh indvida vaianc is sn in vy go diffn olatons whn socity dmonsat qit diffnt caaiti s. Fo xaml, th data of ag and olags 99) comd fom many stdis cay showd hat yong mn can toat mo comssv oad down thi lma sins than can old mn and smilay mn can oa aot an additiona thid mo load than can wom n whn mac hd fo a Y hman ights lgslation whch is dsignd to cat fainss and qity

ntroduction to the Issues

5

y dsouagng dsnons among grous aualy us oldr fmals at grat rs tan youngr mn By no allowng a 64yarod ostooro woman to  trad (and rotd dnly fom a 20yarod ft 90g 200l mal n tms of toatng sn load t lgsaton snts a maor a or ntlgnly ml mntng tolranasd gudlns for rottng wors

Deficiencies in Current Low Back Disorder Diagnostc Practices t s urnty oular for many auorts o suggst tat a toul s not a md al ondton y asst tat ysal loadng as ttl o do w low a n omnsaton lams; rat ty lv wors oman of a olms n ordr o nt  rom ovy gnrous omnsaton aags o  to onvn ysans ty ar s Aordng to s vw any omanaly asd njuy vnon or ralaon rogam s uslss Vaals wtn  psychosocial s domnat any ologa o mana vaal.  s s tu n ts oo s of no valu sould  aout syosoal ntrvnton os wo ontnd a syosoal fatos domna low a ssus ar wlulsd sntss and ys ans. or xaml Pof sso Rard Dyo 998  summazd t vw o f many "Consd t ollowng aadox  Amran onomy s nasngy ostndusral wt lss avy aor mor automaon and mor roots and mdn as onsstnty movd dagnost magng of  sn and dvlod nw orms of suga and nonsuga tray Bu wor dsalty ausd y a an as sadly rsn s ln o asonng assums ta modn wor ( mor rtv mo sdntay s alr or t a tan t domnanly ysal aor of as gnraons  vdn suggsts owv tat  r tv motons qurd y som salzd modn wor or t sdna natur aratrZng otrs rodu damagng omana strssors In fat t varty of wo  rformd y our gratgranda nts may av n far at. Dyo aso sms to assum a nonsurga tray as n aroaly osn for a ndvdua was I suggs tat narora ray rsons man qut ommon ofssor Alf Namson 992 wrot at "most as ontol studs of rossstonal dsgn tat av addrssd t mana and syosoal ators nlunng LBP (low a an nudng jo sasaton av onudd a t atr lay a mo mortan rol tan  xnsvly studd man al ators Y non of t sval rns d to suort s onon mad asonal quantfaon of t ysal o dmands. Gnraly s studs found tat syosoal var als wr rad to low a rouls ut n t asn of masung manal loadng y ad no an to vauat a loadng rlatons. Fnally D Norn Hadlr 200 as n rar outson satng for xaml at "t s unar wr tr s any manngul assoaton wn tas ontnt and dsang gonal musuloslta dsords for a wd ang of ysal dsor ds and ta on  ot and nay all mulvarat ross stonal and ongtud nal suds dsgnd to o for assoatons  yond t ysa dmand of tass dt assoaons wt t syosoal ontxt o worng Rn vdn larly sows tat atoug syosoal ators an  mortant n moduatng atnt avo omanal omonns ar motant n ladng to low a dsordrs and n  vnton  oson tat omans lays no rol n a a and avty tolran an  ld only y tos wo av nvr rfomd ysa aor and av not xrnd sand  wor mods

6

Low Back Disor ders

h mu e empoye to voi ili ijuy. While he cieifc eviece  boutey ecey  will oly cofm the oviou to hoe who hve thi eeiece.  fi it peveely iyi whe hyci tel me ht hey e w, fte mii wok   eult of  ty bck eioe ee o hycl ok le to ele t thei ptiet. Peh epeece wih  viey of hevy ok  ith ii i hou be eque fo ome mec! t i he eeti o ivete  uet he k mg i tiue mge o ito ychoocil fcto,  efomce to pve clue fo he ei  impemeto of ete eveto  ehiltio tegie fo ow ck ube.  the folowi ecio  wil e evel comoy he ief u ck ijuy.

Is It True T hat 85% of Back Troubles Ar e of Unknown Etiolo? o ck  eot ofte meto the ttitic tht 5% of o ck touble e of ukow etiolog. Thi h le o he opu elief h i ck ue e ievitle  ju  hpe  temet th efe he leh  of letue liki pecific mechicl ceio to ecific ti me. Some hve ue tht hi temet  my he p ouc o f oo ioi  of clic ech  h e of thi eete (e.g., Fich, 999  fie  mut oit out th  fte ee o the ofeo of the igoic. Ech goup ttemt o tiy he pm yfuco ccoi  o it picul ye of e me . Fo emle,  hyc l hept wl temp go o ue ecio egi mul hey oche whe  ueo my f  i iecte o mk uic ecio moe helfu. Some clici (u geo fo emple eek  pecif c iue   i c  te Fm hi eectve eve block oceue hve ho cocuve  ouce oi i wel ove 50% of ce (eg Boguk e  996 Lo et ., 996 Fich, 999 Th h pompte eech to hch tue e evte  e cie  pi eeto. Biomechi ofe ue ht thi my e eev ce  ie with lee biomechc h lee iue tee Thu  me iue my cue oveo o othe iue cug i hethe the me tiue  ieve o ot Thi i why ohe ciici emloy kle pvocive mechi c log of pecifc tiue to evel thoe tht hut   e o eve lo pte o moto pe tht cue pi. Thee type of fuctil e e he i igg hey   eveoig le ful moio pte bu the pce of fucto goe will be hiee with  oo uei of ie bimechic Futhemoe hoe wth  hoouh ue of he iomechic of tiue mge c e guie to  ee igoi by ecotuct he ii ig mechicl ceio A tio eefit of h poch  tht oce he cue i uetoo t c e emove o euce Ufoutely my ie cotue to hve toule imy ecue hey cotue o ege i he mechicl cue Fmiliity with pie mechc il e thi myth of uoe ck ouble  euce the pecetge of thoe wih ck ouble of o kow cue Eve with  tiuee igo, theh pctice of teig  iet wih99  eFo cfic i with  iu hepy o ove poucve Roe emple ucce te wih my cce thepie gety imove wih the combiio of chemothepy  iothepy. Opim ck ehilttio equie e mov of he cue  the io ehp of tbity mu of tue they  omehi ee epe o the iet Few pte fl to  compee fit fo fuctiol goi whee  igul poch wil ye oim eut Both fo iteettio of he eue  fo ciicl ecio mk t wou pe ue o queio the iotic cite eee efoe  give ii i ie

ntoduction o the ssues

7

Lmttions in issuebse dignosis should no be used to sugest tht deteminin the cuse of bck oubles is ieevnt no ht the mnu/medic tetment in some cses is uitless leving psychosoc ppoches to pevil by eful. Even gven the cuent imittions the gnosic ppoch s pouctve fo guiing peventon nd ehbiltion ppoches

Is It True That Most Chronic Back Compla ints Are Rooted in Ps ychological Factors ?  While thee is no  oub t th  mny chonc bc k cses hve psychologicl oveys te signficnce997) of psychology ophse bck poblems often getly Een Thompson cone the bnkuptsepetise whenegeted. efen to. spne ocs who e unle o guide impovement in thei ptients nd deful to lin the pients n thei psychoses These physiins ehe dismiss mechnicl us tion o ssume tht mechnicl usion hs been equtely dessed At ou univesity cinic  see ptents who hve been eee by physcins fo onsult hese e ehe ele pefomes o the vey difficult chonic d cks who hve filed wih ll othe ppoches. n spie of the ct tht these people hve eceived vey thoough ttenion I m coninuly hetboken o he bout th miniml noice pi to ongoing bck stessos n o the eecises tht hese ske cse bcks hve bee n pescibed tht hve only ece be thei co ni on The dy befoe I wote this secton I sw  clssic emple. A womn hd sufee fo ve yes on sbily nd h seen no ewe thn 2 speclists fom  vety of discipines Although sevel h cknowlee tht sh hd physicl concens he toubes wee gey tibue to ment epession. Sh consisently epote beng unble to tolee specfic ctivities while eng e to toete othes. Some povoctve tesing confimed he epot togehe wih uncove in  peviously unignosed thitic hip Fo yes she h been fithuly folown he insuctions of he helth ce povies o peom pevic tils kneestohes stetches fis hing n the monng n situps to tke he e dog fo wks nd so on Al of hese ilchosen suggestons hd pevente he poseo isc (with sc icbse oubles f om mpovng. As we wi l see te these types of toules typicly o no ecove with eionbse ppochespticully fist hing in the monng Moeove he ledi sed osion lods tht she epeenced evey tme she wlked he og eceede he tolence Alhough she epoed vuuming s  mjo eceto of he toubles he helth ce povides hd nve shown he how o vuum he home in  wy to spe he bck I suggesed th emovin these dily ctivites nd epcng he eion stetches with neutl spine pition weness tnng n isomeic oso chlenges woud likely stt  slow poessive ecove pten I believed h he psychologcl concens would poy disppe wh he bck sympoms f she fel ino he typcl pten. his ptient with ths typicl stoy hs  esonbly goo chnce to enjoy lfe once in (Note: hs pien ws ck o wok nd off he ntidepessnt medicton  the ime o pofing his mnuscip None of the epets this womn hd seeninclung physic hepiss chio pctos psychologists physiists neuoogss  nd othopodsdessed mechni concens Ths s not o conemn hese pofessons but he to suggest th shing epeiences nd ppoches wl help us to be moe successu in helpng bd cks ehps these pofessonls wee unwe o the pinciples o spine unction th types of os ht e mposed on the spine tissues duing cetin ctivities nd how these ctiviies nd spne postues cn be chnge to getly euce he lodsin othe wos he bomechnicl omponens.

8

Low Back Disord ers

Th book i  temp o heighte the wee  o f hi mechic ppoch Whe  ou ve hh  hve fou etvey fw e who ppe wi to equtely e the cue of bck toube whi wk to fi h mot ppit thepy My ye of lbot oyb  wk mbe with cob t i t ye with my iicl colegu hv ve m with uiqu iight A  eult  m o o quick to bm the choc tit

Does Pain Cause Activity ntoleran ce? Eviee tht mechicl tue ovo cue mge  couve ut oe h mge u p  o choc i wokimut ite? Seve, limit umbe of tuie hvth mechicly o cu chemiy tiue t e-but puce ciicl p tte (The bece of efitive lee tui i ue t the eh iue of efom vive oceue  bby ot bue uch tuie e without cietifc meit Fo emle, the ioig wok f Hh  clue  96364) ocume te i fom the jectio of hyet  ie ito ecfic ie tiue thought  be ie fo me. Subque t thi wok eve oth uie uggete the ik bewee mehic timulto  i, fo emple, he wok of Hu  o leue  1988), ocumei   m ge ic The  iefutble evece th vetebl ic epe fcue  vey com mo  oy eut fom mechc oveo (Bikm im  Hlweg  989 uig , Clgh  Mci ll 2001 ) Th thee f ctue e l fu i ec y ecim tht we ubjecte to whplh (Tyl o, Twomey,  Coke , 1 990) lo ehe oth f c of h ih i  H u pefome m  eci f io t to 692 c f which 14 emote ek  th veteb boy, cofimg  epte fctue ou of hee c 28% ouce eve p ie 64%) pouce lly t pi678 owith u m iy p  cot, oly  % of coco th mig c  ep l o iutio ouce vee pi 31% wh co p 17% with mi ,  41% wth o i Thi evece povie og upo fo the oio tht oig ue m  mge cue  Eve thouh i c imit fucto  civity i oh e f h boy me l ut tht thee  ot ke whe  b bk   iu. Tel 997 pve  ieetig peectve wh he gue th i po mcie,  o oe t utiol mecie, t  w epe th om ju eque moth of thepy o c eve cue etieme fom he civity H  tht hete eceivi ecze o mecie ce e  ieetig gu to oie ie my  highy motve e  top hyc coito e we  hve cce t goo meicl ce,  e fully come eve whie iju Thei iu  i c cue bece fom ly fo ubt mou of im  c eve  thei uiv cee Teel eme u ht o l logtem hoc i i  ey pychoocil coce,  imlie by ome clii Th ii i m of he uefule of hyc poche imytobeue they hv o b uccfu i eucig ogem oube i  ievce h iet

Inadequacies in Current Care and Prevention of Low Back Disorders My bk ptie c tety th he ce hey hve eceive f the ouble  ot tfcoy Wht e ome of the fcto tht cotibute o he iquy of thi eeie? Cey oe of them i the fc ht the eimii vce o

Introduction to the Issues 9

whh mny pinl s th ttmn romnis n  uit nun. olown  om mpls of th iu th u ousn • Plethora of studies on "backache. Ni bkh i nrly imsil t qutiy n vn if t ou  quntfi offs o uin fr intrv tion A uh ny suy of rmnt intvntio on nospfi kh i of litt us Som k uf f wih iso  prl m o mp n w i rn uit iffrntly rm ho wth lmntou m o fs rlms Efiy su tht  nt ussiy b bks n u ith nonpifi v rss. Thi h l t th i ht othi ok th vyhn o u o  imit r Mo tus o nopii kh rtmt l not  hfu o wl th  imi rvi f hs tus ofr rl nsih /

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V-shaped nction of loading and resulting injury risk k mny hlth-

lt phnm h ltionhi of w k tissu on t njuy ik rs t frm  Uh funtinnot  monnily is i. or m vruy vy nutrn w l u posoni  wit h iv os lv u hlth u r in hir sn; thu hr i  mot tmum.  h s ith w k n vn ut ht two ion n h Uhp rlioship r lmtioo muh n t littl or 97) u th hvy rk is o  th k ut h  on fi ? Porr ws rly rfrr o wrk  uin hl n vrility o h th tm of th U n h wr symms rom  iil rsiv suiit lin is ns t u tnhnn n tuhn f tius but ssv v il rul n wknn. Thi lk f nsnsu i th lirur n h murmt f our h  m i (Mrr t . 2000) A mor vn ustni i rqu. • Relationship of intensity, duration of loading, and rest periods As un  Mrs  997 outslty som tus tht  rt ty  i  rt pinn ij L  or h ust h sus it i pn n hwi h psur w mur  whr th mrt optmum  su hth rs o h rmnt populton Th sutivity of uh su is uthr unrso whn w nsir  h qu ion  th   i n i fn w n  su irritt n tu m? in primnt n hum n nim tiu o rou m rvl th utmt ll l yon whih njur u imhni hn pin n r u to trutus.  r if y  u ou irritt iu t rou rmnu in t oin vl w w h viy trmn tolerance y t  prlo on.  t v n prt y Vimn  olu 995) sus tht th rrsv vlopmt  onitions suh s inl tss rsuls from y  pi subfailure tivity Th umntl qutin  Coul suh onin  v y vin prvnin strtis tht inlu opm  r ri n ontrin th ution o psur?

III-Advised Rehabilitation Recommendations

Ths fiu t frm rsh n t ult proprity hv rut i mny vrmiitis out low k trtmt whh hv i tur  t m inqu rtmt rts  mmtos. A fw f th mo mmn rmmntis r k hlth  i hr • Strengthen muscles in the torso to protect the back it th ini mphi n inrin k mul rnh sv tui hv hwn ht mu srnth nnt r who wil hv fuu k rous (BirnSrn 9 On h thr hn Lut   ollu  99 hv shown tht mu ur n urn

10

Low Back Disode s

(as sd t strngth is rttiv Why thn d any thrauti gras ntnu t hasz strngth and nglt nduran Prha it is a hldvr inlun r th athlt wrld n whih th gal f traning is t nhan rfran Prhas it s an inun fr th vasiv us  bdyuildin arahs n rhabiltatin As will  shn tal xris thray us hn h hass shits away r th nhannt  rfran and tard th salihnt f rvd halth In any ass th tw ar utually xlusiv • Be d he kee whe performing iup Clinians dly rnd nd ing th ns drng a stu ut n what vidn A rustrating ltratur sarh suggsts that this rtin ay b th rsult f linal wid Intrstinly Axlr and MGill 99) dnstratd that thr s littl avanta t n n sitin vr th thr and in at th issu is rbaly t au thr ar far bttr ays t hallng th abdinal usulatu and is lwr lubar sin lad (tradtinal situs aus sin lading nditns that gratly lvat th ris f in jury. This issu s n f any that wll b hallngd n this b. • Perforg iup will icree back healh s this a tu statnt r an artifat f xrintal thdlgy Ds it what any wuld li t  liv thr is nly ild ltratur surt r th blif that l h ar fit hav lss a trubl (althugh stiv vidn is inrasing fr xal tvnn t al 20 ntrstingly any f th studis attting t valuat th rl f inrasd fitnss in ba halth a tually n ludd xris s that hav bn nwn t aus  a truls in any l r xal any hav atttd t nhan ainal strnth it h st us Aftr xaning th l ubar r ss n that rsults fr rfring sit us with ull fxn f th lubar sn t is lar that nugh stus ill aus daag n st l Eah situ rdus lw ba rssin lvls ls t (NISH) atn lit and th Natinal Institut fr Ouatinal Saty and Halth ratdly rssing th sin t lvl highr than th NOH atn liit has bn shwn t nras th ris f ba dirdrs (Axlr and Gll 199 Thu rahng a nlusin vr th rl f ftnss fr th ulish litratur has bn bsud by illhsn xriss Inrasd ftnss ds hav urt ut th way n whh fitnss is inrasd aars t b rital. • To avoid back ijury whe liig bed he kee o he back Prbably th st n advi givn by th liniian t th atint h ust lit i t bn th ns and  th ba straight. In additn, this frs th funatin r virtually v st f rgni gudlins rvid t rdu th ris f rrlat njury. Vry fw jbs an b rrd this way. urthr dsit th rsarh that has ard sting and squatting styls  litng, n nlusn as t hh s ttr has bn rahd Th issu f whthr t st r squat durina lft dns n th dinsins and rrtis f th lad th haratristis f th liftr, th nubr f tis th lift is t b rat and s frth an thr ay in at b safr thniqus altgthr Muh r ustiiabl guidlins will b vl latr in th txt • A igle exercie or back abiliy program i adequae for al cae t is urrntly ular t rt th traning f singl usls t nhan sn stability Whil th riginal rsarh was tivat by th intntin t ruat rturb tr attrns that wr duntd t b th rult f injuy thrs hav sintr rtd th data and ar rting xriss t train usls thy bliv ar th st irtant stabilizrs f th sn. Unfrtunatly thy d nt quanty stality h rss f quantiing th ntributin  th anatal nnt t staility r vals that virtually all usls an b irtant but thir irtan ntinualy hangs with th dand f th ativit and tas. t is tru that daa t any f th sinal tissus fr hanal vrla rsults in unstal jint havir aus  f

noducion o he ssues

11

bienil ne t te int wever te erturbd tiue i rrely lind t te yttly in  ie wy re iely tr tiue be invlvd nd i n re invlvd will reult in different nyin tr diturbn Ti vrity in ibl etiie en tt  inle ile rebilittin r ften ill nt r I bility t b retred t te exene f nrl jint tbility Or i tbility fO be etblied firt wit enned biity   endry dlyd rebilittin l Or i te lini iture ex fr exle in  itutin in wi ine tbility i needed but tni  tivity uin rni i xur neeitt i biliztin Ti xle ne f ny tt uld v ben en illutrte te llne f nurin uffiient tbiity fr te inl tiue N il r ingle r will rdue te bet rult in ll e  dritin nd dt rented in ti b ill e uide te frutin f exeri tt nur ine tbiity

Can Back Rehabilitation Be Completed in 6 to 1 2 Weeks? Se v uggted t t dd tiue ud el witin 6 t 1 2 wee. n ft ny ve ued ti runt t u t ntin tt wr intlerne xdin ti rid  n  tntil bi e g.  rdy 1 995) but t f  y il iu. urtr  ve ueted tt tient revry wud b bttr ved by redirtin rebilittiv ffrt wy fr yil re Ti itin n be refuted by dt nd indite  iundertndin f t lxiti f in teni. e net tt tiue  witin 6 t 2 wee r t b riinlly bed n nil tudi reviewed in Sitzer 1993. Hwevr nt ll un tient get bttr  quily endeln 92) nd te fllwu tudi fr  defi ned dirder  u   il re  lli ng in te u r f inr in tiue dirutin e Rdnv et . 1994). Evidn ill be rented in lter ter f bt enil nd nurlil n  linger r yr ubquent t injury. i inlud l f vriu tr ntrl reter tter it duented yetri ul try nd tr didr Ti ugt tt tinjuy nge r nt  il tter f r dge elin. lin re nly  few f te tye f d tt n be ln ter indd: •

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Sifi tiue u  ligent fr exl v been n t t yr t revr fr retively inr inult W Gez nd Aen 19  intervebrl tin unit fr  lex eni invlvin inrit intry n te rt u tt de t ne t ne te bin i nd ldin n nter rt r te eretiv f pathomechancs ny rert ve duented te de f bienil ne itd it initil di dge nd ubequent int intbility nd endry rtriti wi  y te y er t rr eg  Brinnn 1 95 irldy Wil i 1 99. Vidn nd llue 995) duented tt vetebrl tyte r t iy itd it endlt irreulritie nd di bulin Oteyt r nrlly etd t be endry t di nd endlt tru but t yr t dv

u t uet tt b trub re nt enily bd if tey linr lner tn  f nt nly dentrt  liited exrtie Antr quetin i Cn tee b trube liner fr  liftie In ti nntin it i intereting tt elderly e er t lin but bd b l tn yungr ele Vlenburg nd Hnen 92) wed tt b truble r r

12

Low Back Disor des

equen dung  he younge yeas Webe  98 povided fhe nsight by epotin g on patients who wee 0 yeas post disc henations some o them ha had sugey while ohes had not and wee engaged in senuous day acivityyet al wee sill eceving tota dsability beneits! I woud appea that the cascade o chanes esult ng om some om s o tissue damage can tae yeas bu geneally not lone than 0 yeas Although the bad news is that the affected joints stfen dung the cascade of change he good news s ha evenualy he pan s gone o summaze, he expectaton tha damaged low bac issues shoud heal withn a mate o wees has no foundato n n act o ngetem oubes do have a sustantal biomechancal/pat hoanatomical basis On the ohe hand, toublesome bacs a e genealy not a fe senence

Should the Primary G oal of Rehabilita tion Be Rest oring the Range of Motion? Reseach has shown that an inceased ange of moton n the spine can inease he is o futue bac toubles eg, Battie et al 990 BiengSoenson, 984; Buton, ilotson, and oup, 989. Why then does nceasing he ange of motion emain a ehabitation obecive? he st eason discussed eae is the need to quantify educed disabiity as defined by the MA Second thee is a hodove philosohy fom the athletic wold that inceased ange o motion enhances peomance hs may be tue o some activiies, but i s untue fo othes As wl be shon ths philosophy may wo o othe join s, but i genealy does not wo  o he bac  n fact success ful ehabilation fo the bac is genealy etaded by foowing athletc incples

Me chacal oadg ad the Pocess of I jy : A Low Back Tisse I nu r Primer Any clinician completing a woe/patient compensaion fom s equied o ieni he event that caused the injuy Ve ew bac injues howee esult fm a sinle event his secon documents he moe common cumulative tauma pathway leading to the culminaing even of a bac in Because the cumnain event  falsey pesumed o be the cause, pevention efos ae then focused on that een his msdietion o efts as to dea with he ea cause of he cumuaie tauma Whe a genec scenaio fo nu is pesented hee chapte 4 fes a moe ndepth disc ussion o f in fom epeae d and poonge d l oading o specfic tissue he pupose o his secton s o pomote consdeaion o he many facos that moulate the i s o tissue fai ue and o enc ouage poing to geneae a pppiate hypothese s aout injuy etology nju o failue of a ssue occus when he apped oa exceeds he flure tolernce ( stength of the tssue Fo he puposes o this iscussion, inuy l e defined as he ull co ntinu um om the most mino  of tssue itation u t mitauma nonetheess o the gossest o issue ailue o example, �eteal factue o igament avulsion We wil poceed on the pemse hat such dmage geneaes pan Obvously a load hat exceeds the ailue oleance o he tssue, aie ne poduces nuy see igue     in which a Canadian snowmobe aiboe an d aout to expeence an axial impact with the spine fully lexed is at is o steio isc henation upon l anding hs nuy p ocess  s depicted in fi gue   a , hee a magn o safety s obseved n the is cycle o subfaue load n the econd loadng cycle the apped load nceases in magnude simutaneousy deceasing the magin of safey to zeo at hich point an nju occus While his descipion of low a injuy is common, paticulaly among medical pactitones ho ae equied to identi

Intoduton to the Issues

13

Failue toerance

Magin of  aety Loa



b

Tme

a)  rn o sy s obsvd n h rs yl o sbl lod. In h sond odn yl,    ppid od inss n n d, s nos y dsn   n o sy o zro,  wh pon n njry ors  h Cndn snowmob dvr (h or in hs s wo sold know br) s bo o xpn n xl o pssiv mp lod o  lly lxd spn  on- pp li on o od n rd h rn o sy o zro s  ppd lod xds h srnh or     on o  sp porin  sss. Reprinted from J  h 0 () S.M. McGil l," lnvited paper: Biomechanic s of ow back njury Impl ications on crret practce and the c lnc, 6  99 with permss o rom Elsevier Scence

 ijusig vt wh ompltig foms fo woks' ompsio pos m xp suggsts tht ltivl fw low bk iuis ou i this m Mo ommo iju duig ouptiol d hti dvos vovs umul tv tum fom pttiv subflu mgiud lods  suh ss iju s th sult of umud tum podud b ith th ptd pplitio of ltv low od o h pplitio of  sustid lod fo  log dutio s i  sittg tsk, fo xmp A idvidul lodig boxs o  pll who is pdl lodg th issus of th low k sv l tssus oud b t isk to  subfilu  lvl s figu  2 b

are oleance

Fale oa



Margin o aety

Time

 12 (a) Rpd sb  l lods ld o ss  , dn h l  oln , dn o l  on h Nh rpon o lod, or box   n h s xmp   Reprinted from J  h  0   S.M. McGil," lnvited paper Biomechanics of low ack injry mplcations on crret practi ce ad the clnic," 6  99 with pemission fom Elsevier Sciece.

14

Low

Bk Dsodes

princs a slow dgradaion o  aiur olran c (  g , ra  Ada an Hon 985 Brncann, Biggann, and Hilwg, 989 As sss aigu w ac cyc o oad and corpondingly h alu oranc lowrs  argn o say n aly approach zro a whic pon hs indiidual ill pnc o ac njry Obiosly  accuaon o raua i or apid wi ighr load Carr an Hay 9 nod ha, a la wih bon, aig alur occr ih r piions whn h appid oad is closr o h yid srngh Y anohr ay o produc njry wih a subailu load is o ssain ss conanly or a pio d o i  Th rodn sown in gu   3  wi ir spins lly d or a proongd prod o i, ar loading  posrior pasi is  and a iniiaing dpndn chang n dic canc ig 3a Unr usaind oads hs viscoelstic ssus lowy dor and rp  san load and rsan crp cas a progrssi rducion in  ss srng Corpondingly, h argin o say also dclins unil injury ocr a a pii prcn ag o i strain (i a  breaking strain o a paiclar issu o a s worrs ar no liing a hay load; sipy saying in i psr long no il nually nsu njrio daag Th in ay nol a sing i, or a copl pcur ay g in wic sral iss co inol or apl,  proongd soopd posur ipos load on h posrio r iga n o  pin and posrio irs o h nrrbral disc h assocad rp doaon a liay podcs icoailur g Adas, uon, and So, 190; MGil and own,  992 ay niia anor chain o ns Sch d ligans inr as join laiy wic can lad o ypion inj o h disc an o h olloin sqnc o ns:  . ocal ns abl y 2 nj\ o nisgnal scs 3 Encrasing sharing and bnding loads on  nua ar Tis laiy ains or a suanial priod a h prolongd oop

Fiu 

Fi d

Mgi f fy

Appid d



b

im

a) hs odm wh ly  xd  b sp s  lod pos o pss v sss o  lo do  1  d  h l  ol  l d o  l   h  h% o ss s 

nto duction to the ssu es

15

ntnng t pro o t  n th\s way emhasizes why sn"le  rveno ppoce ofe f. Moe ffee ju ntrnton trtg ognz n r th oplxt of t orlo Aon of long togthr  nr h ojt of n prnton trt  to nr tht t ptton tt  xpo r to lo p p th n lly x th t t g Th xor t

Tolra

Appied  oa d

lo  nry, t n th po o  ng rotr th ppl  lo t  o  (th rt to llo th hln/ptto ro to grlly r th fr tolrn t  hhr ll W h lry n ho t lon n ny r for n opt h rtnh Tme of not too h n not too lttl lo tnn   4 od  s ssry  or opm ss  th optl lo for hlth no oth h hh Wh lod  d h sbsqn drdon rt n n of n n t oh o olr r oow d by  prod o rs,  d pv ss rspons  rss or ss "r  n   Fgr 14 prnt  fn lot htoy to rsls rom h opml blnd o r nd s   ontrt th ln ong long t n  md  d ss bomhs . t t ton. In ry, th njy po y  ot th th ry hh o  t rltly o o tht r rpt or tn. Th thr/or ton ntt goo xnton of njy n t ong htry for tntl ro o t pro to th lntng nj y nt. t   potnt to on  tht Rst

y fonn on  of n  ont o gnt not rt n  l r rl of nryh prtlry ro   rtyy of tt

A Final Note h lt ontro nto n th hptr ltrt th n fr th K rn t  n th rt of th txt n  th rln o th   on th fo  Rt th g to  tt onntonl o  orrt rt on th n n thn r yor own opnon

References d  d H w (985 Gdul  plpe Spine, 10: 24 d  u, W  S, RR (980) T ri  flex f h lu v l j Sine : 24 Americ  Mdic Association 1 990 Gui   vlui f p1e p 3r dii} l, T,  Gill, S.M. 1 997 Chig he e bmi exrie    l dg  ue ls. Mediine and Sciene in o and Exercie 9 804-81l B C  S Fih, LD plr, D H TH h  d Wly,  990 T r f pil lxiiliy i k pi pl h iury  prpiv udy Sine 15 76-773. B-S F 194 h u  rk dc fr l l vr  -yr pri Sin 9 106-119 du N D ey  R, pril c,  S  hwzr, R 996 Preci digi  pil p  Cmpl,  d Pain 1996An udated eviewpp 313-323. el [P Pr

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ow Back Doe

Brickmann P (1985) Pathology of the vertebral coumn. Ergonomics 28: 3-24 (1989) Predctio of the compressive strength of Brickman, P, iggema, M, and Hilweg, D. huma lumbar vertebrae Clinical Bioechan ics  (uppl 2 I-S7 Burto A.L. , Tillo ton K.M ., ad Tr oup, ].D .G . 1989) Preicton of lo back trouble frequency in a worki g popuatio. Spine, 1: 99-96. Carter, D R , and Haye, W. (1977) The compreheive behaviour of bone as a wo hase orous tructure jOrnal o/Bone and joint Surge 58A: 9. Deyo A 998) ow back pain Sientfi A ercan  August 95 997 A iterature review of low back disorder surveilance mea Ferguson, S.A., ad Ma'a WS. sures an risk factors Clinical Bioechan ics 12 (): 2 11 -226 Fich P 0999, November ) pnal painAn Auralian perspectve  the prceedings of the ' Worl Congre of the Iteaional Federatio of PhYica Medicine and ehabiiaion Washigto DC, 226 Foryce WE. (Ed.. (99) Back pain in he worlac. Seale IASP Press Gunning, ]L  Calagh an, ].P. and McGill, S.M. (2 The ole of prior loaing histo and spna posture on he compreive tolerace and type of failure in the spie usig a porcne rauma mode Clin ical Bioechan ics 6 6) 78. Hader N 2) EditorialThe bae of the agig orker Spin 26 2: 9 96-6 The aatomical basis for low back pain Acta irsch,  gelmark, B.E, an Mer, M. rthopaedica Scandinaica  ( u, K Zucherma, ].F Dery , Whie, A.H Godthwaite, N., and Wynne G .  98 8 Painful lumar e pate isruptios A sigificat dscographic fidng. Spin 1 e n 76-78 Jager, M. utman, A. and Laurig, W. (991) umbar oad durg onehanded brcklaying InteaNonalJoual 0/Industal Ergonom i 8: 26-277 Kirkaldy-Willi, W. ( 998 ) The th ree phase of the pectm of degenerative diseas n: Manaing lo back pain  2ml ed) New ork: Churchill-Livigson.   6 Percutaneous rado Lor, SM, arsley L, Was B, McDonald GJ and Bogduk, N freuency neurotomy for chroc ceical zygapophyea joit pain e Enland joal 0/ Mdicin 5: 72726  995)

Luoto S, pai. eliovaara, M, urri, H ad Aarenta, M. Static back edurace and h risk of lo : 22 ack Clinical Biomchani Maras W.S Davs KG, Heaney A Maitis, A and Allread W.G. 2 The inunce of psychosocal tress geder an persoality on mechanical loading of he lumbar spi Spine 2 3

McGll, SM ad row   99 2 Creep response of the lumbar spine to prlngd lumbar eion inical Biochanics 7:  Mendeon, G.  98 2 Not cure by a verdic t: Effect of a lve setlement on compensaton claiman ts Mdicalournal /A ustralia 2: 29-23 Nachemson A 992 Newest kowledge of low back pain A crtica look. Clinical hoadi and Rlatd Rarch279: 8-2 Parks K.A., Crichto K.. Goldfod, .]. McGil S.M (n press A comparson of umbar range of motion with fuctional abity core o ow back pai patiets: Assessmt of the vaidt of range of motion. Porer, .W.  98 7) Does hard work prevet disc protrusion Clinical Bioechanic 2: 9698 Radaov, BP, Strzeegger, M, DeStefao, G, ad chirg A  199 laionship beteen early somaic radiological cogniive ad psychosocia fidngs ad outcome durig a oneyea folo up in  patent uffering from commo hiplah. British Joual 0/ Rhatoloy 33: 8

ose, SJ  98 9 Phyica therapy diagnosi ole and functon. Phical T 6 53S-537 Saa , ]A, and aal  ].S. 1989 Nooperative treatme of heiate lumbar neertebral disc ith radculopatY: A n outcom e tuy ou al o/Biochanics 1: 3-37 Spitzer WO  99 ) Editorial Lo back pain i the wrkplac Atanable benefts not attaid British Jou al 0/Indstral Medicine 5: 385-8 Steveno, M Weber, , Smith ]T, Dumas G.A, and Albe, w.]. 21 A longitudinal sdy of the developmet of low back pan i an indutral popuation. Si1 26 2 777 Tayor ]  Twomey L .T and Cork er M. 99) one ad soft tissue injuris in postmortem lumbar spines Parapleia 28: 1 9-29

noducion o he ue

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Teaell, RW 997 Te eil  cic pi Juna an Rach Managn  89-9 Tp, EN  9 9 l c p: up epeie  ew ieci Juna an Rach Managn  195-9 Vaeb H,  He, HM (98 e epe ily  lw bc p  Wi e   ad G ,  E), Spu n dpathc w back pan i  995. Mgei ide, T, Be, M, Gil K Mie, H, i, , d Fie,  ece ii fiig  ei elaiip i e cic  l pie ig i e eipeei f pil eeei Spn  (8 98-95 Web, H 98 u i eii  cle ppecive uy wi e e f bea i n 8  W - , e  M  ,   e, WH 985 Meccl ev  f f  iue: Meue e , if ici, ije,   ee  I N u, H M   elvi,  ( E, c (taua pp 9-1 , C: pple Ceuy C

Bochan

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Scientific Approach Unique to his Book

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i bo oi  oriio vipoi o o  i fi  b d M f  priv v r fro  i   bii d oi ro  pr i fiirz  wi  i r pro  fr oii  of   i i boo d i  p  bi  rd   ii i     i ridd b   ppr A i ioi o d f ir r iir o o    i r ivi ir Fr xp  ivi r rd i   f bii  bri d r  f ifrio 

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rffi o b d or  i d rr o  d (.. p r or ro r   rir o ifi i ri d f Crri of prod ri  wi ff r r bi ri o rr fi d o o

Or pr  ivii    fi i ii r o  of r iri   W i wi  foi rioi o rdi  ri of i d: Aid  d > i  r

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i fr ( j )

R fr  i  i r pr r   d of pr 1  i r  rdd b rd d rood odi  i ir wi  r  io . Azi i  fi r i i w rir  dii do ppr i    dv opd wo  i dii rori i  o  of  prr dod i i boo ( o   " d   r i  rr  f r d vii or d i Or fir    i p for ivi ro i of pi  i wi w prpof     r i d di dd  p  or i ifi i j r  od b i  ivivo b wr vi pop bo or d pi r  for ir ro o r d odi divid i o  r id fro opid  pr

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ow Back Dsorders

In-Vitro Lab  iviro a is qd w oad macis a accato rac iss sc oi qm ad a Xay s o docm ossv iss dama or xam y omi dscoams wt adio oaq cotast iqids w ca doc mt t mcacs o ossv dsc riao W vsta ay otr y mcaisms  t sam wayat is y ayi ooca oads ad moio ats ad t docmi t dama w aoia coy. Sic may ciq isss ca afct t xma sts  dcis o s o ov aot  is ov d y  sci fc sa c q so Fo xam s c a macd s of ma ss to r a cotod fa st cao b obaid ama mods mst  sd. Hr coro is xrcisd ov ic omoiy dt ysca activity ad so t o corast a xmta coor  a macd st o coto sis. O cos t rsts ms b vaidatd ad trrd fo m o b rvat o mas  addio idiy  maos o vac i tato s crii ca  Som yo ss at dmad t s of ma matria a com omisd y t ac o avaab yo ay dad scims. Havi ay sci ms is cca cas omcaics ad ry mcaisms adicay ca wt a Ot mao mtodooica iss s  cd t way i ic ooica tsss ar oadd ras at scific oad ras or a scifc ras o disacmt  sarc mst dcid wc as t most vac to  ss at ad vsi s ximts s o a iva as .

In-Vivo Lab  vivo a is iq i its aroac  atmi o docm  oads o  may ma isss i vvo. is owd ds owr st io s mcacs o o orma fctioi ad of air mcaics. Sic rasdcrs ca o b oty imatd   tsss to mas oc ovasiv mtods a cssay.  itto of t asic aroac s o ca a vta s. is vrta mod mst accay s  aatomy at rsods dyamicay  t rdmsioa moto ats of ac tst sbjc/ai ad mst mmc t msc acvaio ars cos y t idvda  so do it as s o vaa sbjcts' iq moto ats ad t cosqcs of i coics ad si

How t he Vual Spine Work Wi to os t Marras r [ Graata ad Marras 993 ad t McGi ro) av dvod mc ffort to  dvomt o iooicay driv mods  McGi mod w  dscibd r iv is famiari y o  ato  mod a dyamic tdimsioa aaomcay comx iooicay driv aroac o dictimod idivida oadsis comosd of wo disict ats a id sm ad ama iyr tiss dtaid s mod at dtrmis tss oads ad si stabity  is at o  McGi mod is a rdmsioa idsmt rr sato of t bdy si a dyamc oad i  ads as it. wo o mo vido camas a 30 Hz rcod oi dsacms o cosct t joits ad body s mts  t dimsos Wori tro  arm ad t ia s d sm mcacs actio ocs ad moment ar comd aot a joit i  •

Scientific Approach Unique to Thi Book

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a

F 1 he ssue a pei appah eqies w es e fis a s a ya ee-iesa e-sege e  ai he ee eai es au he w a he se e b pas he es i isse fes (use fes ; igaes 9 a e uis f efe is, g, a s  eig)

w ac say LL5) evisy descibed in McGi and man 985) see ie 1a) Usin evic and sine maes the thee eactin mments a cnveted int mments abt the thee thedic axes  the w bac exin/extnsin atea bend and axia wist) The secnd at  the McGi mde enaes the atitinin  the eactin mmnts tained m the inedsement mde int the sstantia estative mmnt cmnents stin tisses) sin an anatmicay detaied thediensina e esntatin  the seetn msces iaments nninea eastic intevteba discs and s n see ie  1 ) This at  the mde was ist descied in McGi  and Nan (986) with  theedinsina methds descied in McGi (992, and the st ecent dat vided by Chwici and McGi ( 996 . n tta 90  bac and ts msces ae eesented Vey biey ist th assive tisse ces ae e dictd by assmin stessstain  ad dematin eatinshis  the individa assiv tisses. Deatins ae mdeed m the theedimensina ba ineatics meased m the sect which dive the veteba inematics  the mde Passiv tisse stesses ae caiated  the dieences in exiiity  each sect by naizin th stessstain ces t the assive ane  mtin  the sbect Eectanetic instmentatin which nits th ativ ma anes in thee dimensins detects the isatd mba mtin The emainin ent is then atitined amn the many ascices  msce ased n thei activatin ies mased m EMG) and thi hysii ca csssectina aea The ment is then mdated with nwn eatinshis  instantanes msce enth  ethe shtenin  enthenin vecity Stan and McG i ( 995 descied the mst  ecent im vements  th c vity eatinshi In this way the mded sine mves accdin t the mvemnts  the sbects sin and the vita msces ae activated accdin t th activatin meased diecty m the sect see es  a and ) •

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Low Back Dorder

 Sbje e wi EMG eees a eeage sea  ey easue eeesa ba eas a se avy b The ee spe paay ese  iusa pupses, ag f e pupses  aaysis  eas i aheaa ) ves  aae w e sbje's spee viua ses ae avae by e EMG sgas ee  he sbjes ses F 

Usi iica sas i ths fashi t sve the idetemiay f mutie adeai tissues faciitates the assessmet f the may ways that we hse t su ads Such a assessmet is ecessaY f evauati iuy mechaisms ad fmuat i iavidace iitiatives m a ciica esective this abiity t mimic idi vidua sie mtis ad musce activati attes eabes us t vauate the cse ueces f a chse mt ct statey  exame we ca see that sme ee ae abe t staiie thei acs ad sae thei uma tissues fm vead whe efmi secific tass Cvesey we ae abe t evauate the seueces f y chse mt stateies I this way we ca idet ify thse idividuas with eubed mt attes ad devise secific theaies t eve heathy mt attes that esue sufficiet sie staiity ad sae thei tissues fm damai ad Ou chaee has ee t esue sufficiet iica fideity s that estimatis f tissue fces ae vaid ad ust ve a wide vaiety f activities The theedimesia aatmy is eeseted i cmute memy musce aeas ae vided i aedix A O ccasi if the exese is waated we ceate a vitua sie f a idividua fm a theedimesia ecstucti f seia M sices fm the hi tchate t T4 see fiue 2.2. his cmet f the mdei cess is we dcumeted f the iteested eade i McGi ad ma 986 ad McGi 992). A ist f the ae ume f assciated eseach aes eaii t the may detaied asects f the cess is vided i a seaate efeee secti at the ed f this chate See fiues 2. ad 2. f a fwchat ad exame f the mde cess

f Arh Uqu  Th B

23

F  I hs hsoa phoo a suee sube suag e ope hee-iesoa as o ossig a obeTe isueaio iues ee-iesoa veo o apue boy sege eais, a eog of e ee-esioa oe veo appie o e ha, a 3-SPACE eeoagei evie o eo soae hee esoa ba oo a asss  paioig e passve sse oes, a 6 haes o eeoyogapi eeoes o apue se avaio paes

Development of the Virtual Spine he develoment of he virual spne approach has een an evolutionary rocess sanning 20 years n tha tme we have had to confront severa specific issues, namely ss us of validation a nd how to handle deep muscles that are inaccessile w h su race EMG electrodes. Briey although we have tried inramuscular eectrodes in hghly seleted conditions, this is a limiting invasive procedure. Generally, we estimate the deep muscle acivation amplitudes from movemen synergsts McGi Juker and Kro 996 Ths method s imted, however, ecause it requires a rior knowledge of muscle aterns for a given mome nt comination i n a specific task We try o incoro rae he hi ghest eve of content vali diy y usn g detailed repres entations o f the anatomy and physologcal crosssectional areas, recording stresssrain relationshps and incorporating known moduaors of muscle force such as lengh and veocity One o our valdaion exercises is to compare he three measured reacton moments with the sum of individua issue momens predicted y the virual spine A close match sug gess tha we have succeeded n accuratey representing force Over he past five years hs aroach for predictng indvidual umar tissue loads has evolved o enale us o document spine staility. n this way we can evaluae an ndividu al s motor aterns and ideni straegies that ensue safety and h ose that could result in inury his is no a trivial ask.  requires converting tissue orces to sifness and usng convergence algorithms to searate he forces needed to creae the torques that susain posures and movements from the additona orces needed o

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Body joint coordnaes

Spinl m patoning reacton momen ino indvdual tissues Knemaic poion:

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Oientaon of ib cage and pelvis deermned Hand force Esimae lumbar vetebal posion

EMG

Link-sgmnt ml Theedimensional dynamic Reacton momen about 4/5 Disc

Estimated cene o roaion disc

Inta estimate o cude compression and shea a L4/L5

Mm Stoed spacal matrces: Pevs Rb cage Each veebra

Oren veebae accordng to estimae

Cacuate muscle and lgament lengths and velociy of engh change (dUd) Knetic porion Calculae dsc momen

Calcuate igament sess and contrbuion to esoative moment

Determne moment alocaed to musce

Musce EMG

Musce mode

Common gan or EMG assisted optimizaion

Computed muscle momens

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EMG AD conveed FWR. .E. EMG to force convesion

Pedcted muscle momens equa to sum of musce moments?

Compue toa disc compression-shea using disc mode

�

No Yes

Compare all stresses (muscuar, lgamen skeetal to oeance data Memoy Muscle length and velociy paamees

oad tme hisoies and ag ssues cose to aue

F 4 The mode nput ad outpt are stated n tis fowca up o te pont of calcuatig momets ad tissue oads. Spe sabity is cacated wt a addona modue.

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F  Vaos sages o ode op  is exape of a sbje fexg, pkig p a weigh ad exedig: ba oo abo he ee axesfexoexeso, aea bed ad axa wis a egs of a few seeed ses ogo he oio b soe se oes (e); L4-S o foes of opessio ad sea d ad sabiy dex, whee age posive bes dae hge sabiy ad a zeo o egaive be wod sgges a sabe beavio is possibe 

continud 25

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nsue staity  Potena enegy-ased analyses ae then epoy to dntiy h stabty n dex" in e ach degree o f eedo of the o in, which in tu n rval th jo nt's abilit y to sive a gven loa dng scenario. Ths level of mo ln rprsnts he hih es lvl of sophistication curently available. I has enabd us to challng oncpts ptainin to spine stabiliyore on this n chaptes 6 and 13

References Chlwik ] d MGil S M   996 Mehil si ty f the i viv lumbr si mlit is r iury d hri lw bk pi Ciical Biomchaics 11 (1 : 11 Gr, K  d Mrrs WS 993 A EMG-s siste md f l ds  the lumbr s  durig ssymri truk extesis joural 0/ Biomchaics 26: 129138. MGil, SM 992 A myletrlly sed ymi 3-D mel t predi ds  umbr spi tissues durig lter big joural o/ Biomchaics 2 (: 391 MGl  S Mi  ddis rm R W 986 Th V lv Awr frdurig 1986: ftig Prttiig Spin   11L/ 6-678 mmt ligmetus  musulr mpets (7 : 6dymi

References and Bibliography Pertaining to the Finer Details of the Modeling Process Chlew ki   d MGll S M  99 EMG Ass isted Optimz ti A hybrd p ph fr stimtig musl fres i  idtrmte mehi md journal 0/ Biochais 27  1287 1289

entf Apprah Uque  Ths B

27

Cho ick   nd McGill  S M ( 1 995) Rtionhip  n mcl fo rc nd tif fn in th hol mammlin mucl A imltion tudy joural  Boechacal Egeerg 117: 339-342. Cholicki  McGil SM nd Normn W (1995) Compion of mcl forc nd joint lod rom n optimizion nd EMG itd lumr pin modl ord dvopmnt of  hyd pproch joural fBoechacs 28 (3): 321-33 McGil SM 988) Etimtion o orc nd xtnor momnt contrition of th dic nd ligmnt t 4/5 Spe 12: 1395-1402 McGil SM 996) A rvd ntomicl modl of th domnl mucltr for oro on ffot joural ofBoechacs 29 (7): 973-977 McGl   M  u kr D nd Axlr  996) Corctng trunk mcl gomt otind from MR nd C cn of upin potur for  in tnding potr joural ofBoechacs 29 5): 643-646. McGl SM Jkr  nd Kropf P 996) Appropriy plcd rfc EMG lctod rlct dp mcl ctivity po qudrtu lmom dominl ll in th mr pin joual ofBoechacs 29 (11): 5031507. McGill SM  nd orm n W ( 1985) Dynmic ly nd ttc lly dt rmind lo ck momnt during liftng joural ofBoechacs 8 2): 877-885. McGil S M   nd ormn R W ( 987a) Ef ct of n ntomicly d tid r ctor pn modl on 4/5 dic comprion nd hr joural ofBoechacs 20 (6) 591-600 McGill SM nd Normn W 987b) An mnt of nt-bdomin pru   vil mchnim to rduc pin comprion Ergoocs 30 (11) 15651588 McGil, SM nd Normn W  1988) Th potntl of lu modor l fci forc to gnrt bck xtnion momnt dring qt lif joural ofBoedcal Egeerg 0: 312318. McGil SM t N nd ormn RW (988) Mmnt of th trunk mcutur o tv ml ng C cn rdiogrphy Impction fo foc nd momnt gnrting cpcity bout th 4/5 joint joural ofBoechacs, 21 (4): 329-341. McGill SM Sntguid  nd Svn J 993) Mmnt o th trunk mucultr fm 6 to 5 i ng MRI c n of 5 young m corrc td for mc fir onttion lcal Boehacs 8: 17-178 McGill SM Sgin lrl Bnnt Gtit 994) Pv tiffn oing th umr toro holding out th flxionxtnion bnd nd xi x h ffct of lt nd brth ]., nd Spe 19 (6): 696704. McGill S M  hortn on A nd ormn W ( 1 989) Non- rigid rpon of th tunk to dynmc xil lodng An vtion o crr nt modlling umption Ccal Boechacs 4: 4550 Sntgid . nd McGill SM (1995) h po mjor mucl A thdimnion mchncl modlling tudy ith rpct to t pin d on MRI mrmnt joual ofBechacs 28 (3): 339345 Suto  nd McGil SM (1995) Io-vocity invtigtion of th lngthnng hviour of th rctr pin mucl Eu ropeajoural ofAppld Physol ad Occupatoal Pholo 70 2): 146-153

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Epidemiological Studies on Low Back isorders (LBs) D

efnitve experients are rae in the fes of science an eicne. Instea concusions genealy eerge fro the integraton an synthesis of evience fro a variety of souces Using a sii a approach awyes argue cases in whch each piece of evence is consee ccustantia n the hope that eventualy the circu stantia evence wil ecoe overwheing. Like awyers scientc eseaches athe an regather evience several perspectves with the an goainvesti of uner staning causecicustanta an effect. By stuying fro the eationshps aong variales gatng echanss they are ae to for perspectives that are oust an plau sibe. Ths type of research work together wth ongitunal stues tests the causative factor entfie in the echanistic stuies Other chaptes n this book ae ecate to investgating the varous echniss withn the low back an their nks wth goo heath an isaiity This chapter focuses on the stuy of associatons of vaiaes though vaious epeologca appoaches Soe eaers wil fn this a oing chapterso y stuents nfor e ou ay choose to skip ths chapte But those wishing a fule unestanin of the chalenges that le n buiing a stong founaton fo the ver est inju preventon an ehailtation pogras are encourage to ea on Seveal sectons in this chapte wil hep you unestan the risk factors for ow ack toulespecfica ly the changes in pesonal factors an whethe they cause ack to ues o are a consequence of having the For the pupo se of this evew pupote isabng low ack toules an possily relate work ntolerance will be refere to coectvely as low back isoes (BDs urtheoe the ter personal facto can incue anthopoetric an ftness vaales as wel as otor contol aity injuy histoy an so foh Upon copletion of this chapter you will appreciate the epieiologca perspec tve have a ore copete appeciation for the positons taken n ths book to reuce the econoc pact of low ack sores LBDs an unerstan cetain subsequent appoaches for prevention an ehabitation.

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ow Back Disorders

Multidimensional Links Among Biomechanical, Psychosocial, and Personal Variables As note n ter 2 sevel omnent eole ve elre tt l v bles re t most sgnfnt ftos n D s s n mortnt e ne effetv nteventon mst ess te el e n oneqene of b trble. In ts seton e ll see tt vtll l stes tt roely esre o llte te  emn of tss fon tt ee sbjete to sef nl stessors e t ger r of LBD t tt tee l e to e some mtgtn se.

Tree Important Studies e follong tre stes e eve ere bese of tr t nene n te mltn. Bigos et al. n 1986 Bgos n ollees erome  gl ot ton tt  been ver nlentl n sn onon regrn nj venton n eblttont te oeng lnt n Wngton Stte n te Unte tt  etro setve nvetgton nze 6 njes o w 900 were t t lo b) over   5mont ero n  99 1 980 e ore  orelton beteen t nene of b njY n or sl tn of emloyees eorme b ter rvor wtn x mont ror to te reote nj. e tors onere t o tng to rerent  osol ftor. In 99 gs n ollege nte  lont nl rosetve st of 3020 emloee t oeng rng  te re 279 eorte lo b njres. e esees ollete ersonlt nventoe s ll s qestonnres egr ng fmly n orer ort n ob stst n e •

so nze erson s ometr strengt flexb l t rb t egt n egt. el ftors torss on tt sosol meretrly tose elt to jo enjoment te tongest nene of ll t vrbl n yze In t tose wo stte te  not eno ter job ere 1 tms moe el to et  b nj os rto 1 .5 ) ob stsfton onte fo less tn 5% of te vne s n njr rs ftor menng tt me tn % o t vne  nonte for n ter o sosol ftr l t ont for 5% f te ston of LBD. e tors onle tt te tttll gnfnt to nll moest etve owe of o retn n o sol ftor for reorts o te b n mong nstl orr g gnst te exlve e o n nj moel to exln s obems. s   fr m o te mltons of ter wor. t oe not men tt enl lon s nmotnt et t t s often qote t sort te veont tt ol ftos re te most motnt e o b soes. ntertnl, Mrs n ollege 993) lso fon sml os tos fo ob stsfton .6) n  ssve st  00 eettve nstl lftng jobs ross 8 nstre. 

Odd Ri Pers te most l efnton of n odds raio n e eve tr n exmle. If smoes ve tee tmes te s o eveon ln ner  nnsmo es o  es 6 ot o 10 s oe s oo se to 2 ot of 10 n nono ers), te ve n os rto of 3. , n os rto geter tn 1 t n nree rs fm  se ftor.

Epidemologica Stdes on ow Bac sorders (LBs)

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Very few epieiologically ase sudies have eployed reasonaly roust uantifications of ioechanical psychosocial and personal factrs. wo iportant stuies eet this reuireent. Maas et al. he first iportant study was repore y Maas and colleagues 995 who surveyed over 400 inustrial lifting jos across 48 iferent inustries. hey exained edica records in these industries to classiy each type of o as being either low, eiu , or high risk for caus ing LBD. hey docue nte a variety of echanical variables as well as reported jo  satisaction. he ost powerful sinle variale or predicting those jos with BD was axiu ow ack oent os •

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ratio etweent he low urisk groups and single hichvariales prou ce an os ratio of 404 3.32 )eween lowan anedi highrisk g roups . Other prouce ipressive ods ratios, for exaple, sagital trunk velity (ods ratio 2 .4 for the lo and highrisk coparison a nd 2 .42 for axiu weig ht hanle bet ween t he lo an highrisk gr oups Jo satisf action pro duced an ods ratio of .4 etwe  h lo and high risk groups and  .32 et ween the o and e diurisk g roups . he researchers entered the sinle variaes into a ultiple ogistic regression o he roup of various easures seeced y the odel descried the risk inex well eteen the lo and high risk groups and also etween the low an eiurisk roups Suitably varying the fve easures chosen y the regression process (axi u load oen, axiu lateral tr unk angular velocity averae tr unk wistin velity, lifting freuency, an the axiu sagittal trunk angle decreased the ods of eing a eer of the highrisk LBD group over 0 ties (ods raio 06 . his as a n iportant sudy for speciyin  certain physic al characerisics of jo esin tha reuce the risk of LBD an linking epideiological indings with uantitative ioe chanica  ana lysis and psychosocial factors across a la rge orking popu la ion  

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Noman et a. secondactors iportant to successfully interate cal psychosocial andhe personal wasstuy conucted y oran anioechanicolleaues 99) who exaine injuies that occurre in an auto assebly plant that epyed ore than 0000 hourly pai workers. Duing a twoyear period of oservaion in he pant, the authors repoted analyses on 04 cases an 30 randoly selected contrs Cases were people who reporte low back pain (BP to a nursin station cotros were people ranoy selecte f ro copany roster s who did not report pai n. his is a notale stuy ecause he authors attepted to otain gooduality psychosocia, personal an psychophysical ata n all participants fro an intervieerassiste uestionnaire, as wel as gooduality, directly easure ioechanical aa n the physica deands of the jos o all participants. (Note that the psychophysical ap prah is ase on worker selfperceive sresses.) he study revealed that severa inependent an highly signiicant ioechanical psychosocial an psychophysical factors (entified as risk factors) exised in hose who report e LBP he personal ri sk factors that were included were uch less iporant After adjustin for personal risk factors he statistically independent ioechanical risk factors that eerge were peak luar shear force (conservativey esiated ods raio  )  uar  isc co pression integrate over the work shit (odds ratio 2 .0  and peak fo rce on the hans (os ratio 9) he os ratios for the independent psychosocial risk factors fr aon any studie were orker percepions of poorer workplace social envirnent (2.6 higher jo  satisfaction (n o lower, as shown in the Boein study 7) hgher coworker support .6 an perception of eng ore hghly educated (2.2 Perceptions of hgher physical exertion a psychophysical factor  re sulted i n an ods ratio of 3.0 which is possily related to the capaciy of he worker relative to the job eands. Nearly 45% o the total variance was accounted for y hese risk facors with approxiaely 2% accounted for y the psychosocial actors and 3% by the 

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32

ow Bak Dsordrs

R CK WILL  FN FTN TH 300 B BXS I' V YOU A GOOD EMPLOEE RR! -

ioechanical facos These esuls ae vey consistent wh those eote by Maras an coleaues ( 99 5 an y Punnett an collea gues ( 99  ) Ony a few of the eronal facto wee assocate with reorin BP oy ass inex (o atio 2.0 an rio coenaion cai (os atio 22 Ths case/conro tuy s o hh qualiy becaue it ue a atey o any of the et easueent eho available o fiel use o ae any sychosocial ioechanca, an esonal factrs on all 

articant n he aa ool The evience fro he corehenive uie ugge that boh sychoocial an ioechancal varae are ioran rik facos for LBD  In acu lar cuu lave loain, oint oent, an ine shea oces ae iortant Those claiin tha only sychosocal fact or are i oant or hat only hysica oa in fc ors ae iortan cannot ou n a creitae, ataae e ense, a  it aears hat the aa they quote ail o eae roerly eiher (o oth) hysica or sychoocial vaiable.

Do Workers Experience LBDs Because Tey Are Paid to Act Disab ed ? Soe aes n the literaue aear to isss the nk eeen an an isailty. Most of hese aers cearly sate hat hi noon is reice o "nonecifc back an, noin hat secfic ianoes o iair the ailiy of a oke to erfo a eann ob Howeve, soe ase he auent on he concet that ow back issue inj uy heals in 6 to  2 weeks, whe ohes ae their aguen on a behavoa oe o chonc ain hat is no totaly coniten wth the inins of oher scientific aoaches. A shor scussion o th e ssue an evence eate to hysican ia gno sis, coensaon, ue aage an an is neceay. The osition tha chonc ain an abily ae a uncton of coenaion (an not echanical actos s contraicte y evience ha  low ack toube conin ue aer ea sette ent of njury co ensaton ( Menelon, 982)  Haler  99 ) believe hat the conest etween the aen an the eca ocer chare ith eerinng

Epdemologa Studes on ow Bak Dsorders (BDs)

33

th comn atory award ca h at int to act di ald an d thwart  a ny ncn v o act wl. Tal and Shao (998) had th oinion n a vw o va dint chr onic ai n dord, a dd Rainvl and coll ag ( 99) in anoh vry nic tudy hat cicaly addrd chronc low ack ain Unonatly Hadlr ha takn th otion that mchanical actor ar, o th mot art o ll moanc in ithr caing o rhailitating ad ack whn comad with th ychoo cial modlaor (g, Hadlr, 200) Hi ctv ciaton o h itatur xcld vidnc linking mchanca ovroad o ti damag and ignor vral moant intrvnion di For xaml Wrnk and Ha (200) howd ha ain atrn on atn rntaion, cicaly whthr th an cnralz o no, ar mch mo owrl rdctor o chroniy han h ychooca vaiab thy tdid Th, al thog h th toic o comnat ion i imorant,  i irr vant in dc ion  o h l nk bw n loadng and BD. Comnation  hod no  d o ag againt th xitnc o a mchanical ink wn injy and work tolranc or wor yt o gg that h rmoval o comnaton wil liminat th ca o i damag.

Does Pain Have an Organic Basis-Or Is It All in the Head? Mch ha n writtn ao h aan anc o an organc bai or chonic ow back diail y (an d ohr chronic a in yndrom   A notd in chat   a high a 85% o dabling BD ca a claimd to hav no dniv athoanatomcal diagno i (Whi and Gordon, 982) Two concion hav n ood •

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Many BD atint rnt wh nonoganic ign ggting ychologica diranc a th ca o thir conditon Poo diagnotc tchniq, thr om doco th o rom imitation o idly availa b di agno ticnadquaty tchnolog y, taind hav cldd making o many olid diagno.

Th r conclion gg hat h corrct cor o acon in th ndianod ca i to ignor hyological i and addr only ychoogcalychoocia actor. Th cond concluon ggt hat on hold no ignor h oiili hat mor thorogh diagnotc tchnq cod nath hyica ca and that rhailiaion bad o n tha amion cold  mor  ctiv than haiiation or ychoogical ditranc aon ' xamin ach o th agmn.

Does Absence Of DiagnOSiS Imply Psych ological Cause? Waddll and coag wo many manucit and gidin (g, 980 9 98) on nonoganc ign n ain to ort th notion o ychological dibanc ovrrid ing any ahoanatomical i damag  (ca  non wa dia gnod Tall a nd Shairo  998) wr ot a nic mmay o an xniv xrimnal ira tr gg ting tha th ain ymom may ndd hav a hyiological a Thy rviwd th rcn cinc on h rad o nuron xcitaiy and nitization o adjacn nron o xlan th nation o radiatng an in chonc condion. Chang in noanaomy ar cold with iochmica hang with chonc ain. For xaml n iomyalga atint nmro di hav hown v o banc P in th croinal id lvatd wo to thr tim ov contro ( d n a viw y Ta,  997) Wh il th nonorganic ign dcrid in W add l ar ar imortant conidation n many ca and a a conition to clinca actc, tong vidnc ggt that many nonorganic ign may not b xcv o a athoanatomica mchanm that ha ldd diagno

34

Low Back Dsoders

So hav arg that no link xists twn pain an tissu ama an activity intolanc. n th asnc of no irc vinc som gos hav simply as that ciceptive pain hat is not srgically corrctal or that has not mprv within six ks sho not  rgar as isaling (g Foryc 199) n fact th Foyc onogaph initiat much iscssion incling svral lttrs (. hop son/Msky/asll/Foryc 996). Forycs 1996 statnts that "th cors w ar prsntly on hatns isast an tha "w chang or go rok wr particularly valing. h high cost of tating chronic pain an isaiity aas to hav otiva th lvation of th iportanc of th psychosocial factors so haiz in this onoraph. t is also intrsting to osrv th asnc of any innt biomchanica xprt aong th athor list of th Fo ryc rpot h Canaian Pain Socity sta ha th Foryc por litra rviw is incoplt an os not rflct th (Pain, vol. 6  14 1996) contpoay nrsaning of chronic lo back pain Morovr h Foryc port largly ignor h vinc inking chanica ovr loa to masral changs in spin iomchanics an spinal pain nuomchanica mchaniss. Anothr assption of h rport was that ost sin LD ar nonscific aning siply that a iagnosis was no ma.

Could nadquat Diagnosis B a Faor in Nonorganic LBP? Bogk an colags 996) arg that ain arising fro many spina tisss can b attribt o a ctal painful sion For xapl th fac joints il proc pain upon stimation McCall Park an O'Brin 99) Bogk's point is crtainly coct. Howvr caus not all lsions ar asiy cal i cannot b us to ag hat if a lsion is no tct thr is no organic asis for pain For xamp fractrs an mniscal tars that hav n tct in postmortm stuis hav not X ray (onsson t a 99 ayor woy an shown raioogically on planar Cork 990) or on C (Schwarz t a.   99)  Nor hav f shly pro uc fractus an aticular aag n otwarly tcta raiographicaly in animal ols (ingling an McGill 2000). t ths ar th typical iagnosic rocurs s ntrs tingly ok an colagus 996) an Lor an collags  99) sh ow that incion of anshtic placocontrol iagnostic ocks) convincinly onstrats tha t fact joi nts ar of n th si of a in ori gin. Frthr  isc stui s xaining h pain rpons of wll ovr 000 iscs in ovr 400 pol unrgoing iscoraphy y Vanharanta an colags 98) ssquntly rapprais by Monta t al. in 994 an rport y Boguk t al in 996) sho a car an statisicaly sinifcant corrlation tn isc pain an gra 3 fissrs of th annus fibrois. Most physicians woul proaly not tct ths p fissrs of th annlus In a igoros an systatic sty of iagnosis as on ansthtic locks Schwarzr an colas 99) wr a to iagnos ovr 60% of th BD cass ci in th sty by Bok an colaus 996) as ing inrnal isc isption 39% fact jint ain %) an sacroiliac pain 2%). Bogk an collagus 996) stat "f inappropriat tsts sch as EMG an iaging ar us nothing will b foun in th majority of cass falsly j stiying th  imprssion hat nothing can b foun.  Clarly w must pathoanaoical qstion th satnt finitiv cas. hat 8% of LBD cass ar iiopathic or hav no

Hlpful tratgis for Undiagnosd LBDs So physicians ar clarly fustat with th ay iprovmnt of nianos conic L pa tints his frsraion toghr w ith concrn fo r h financia l halth of h compnsation sys ay hav otivat th Foryc rpot to haiz sychosocial molaors rathr than organically as varials to xpain intolranc to crain yps of activity Bt aling wih frstraion on th asis of fals astions

Epdemoogca Studes o Low Back Dsordes LB Ds)

5

will ot hel the situatio What the are more useu aroaches to uago chroic cases o LBD? As ote earl ier may cl icia s o ot have the exert se or toos to iaose bac troules at a tissuease leve. Povocative testig wll eae may hysicias to ietiy aiu motios a oaig By itegati biomechaics with such testig hysici as may be ai e i  maki uctio al iaos es. I a small stuy Deitto a coleagues 995) sueste that ariatey clasi ie bac a sueers (those with uctioal classiicatios rather tha tssuesec ic agoses o etter with secic treatmets u rther as at ie ts  rogress through the rehailitatio rocess they seem to equire ieet treatmet aroaches or examle  several stu es su ggest that maiu lati o ca e ee icia o acute shotter troules while hysca theay a exercise aroaches aear better  chric coitos (Skargre Carsso a Oerg 1998 A maor mitatio o these stuies is  that oe has assesse roressive treatmets that chage as the atet ogesses through the rehailtatio ocess; rathe they al have assesse oy sige treatmt aroaches Future stues must assess the eicacy o stage rograms  which cat egorize at ets ollow ogressive treatmet i vovi g several sequece a rache I summay the ositio suggestig that there is o etectale athoaatomical bais or ai a actvity itolerace i some atets a thus that they are uctios o oy sychosocia variables oes ot aea to e eeale Imrove tissuebase iagosis imrove rovocatve/fnctonal dagnoss,a etter uerstaig o the iteractios o sychological variales with athoaatomical variaes aear to have romise or helig to imrove treatmet outcomes

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Are Biomechanical Variabl es and Psychosocial Variables Distinct? Are iomechaica varales a sychosocial variables istict or is ther a tr lay etee them that i uestoo woul ueri a ore eviecebae iteveto rogram? Most eots have mae a cear searatio betwee sychosoca a biomechcal actors. But is thee ay eviece that sychosocial actors cou mouate ucu oseletal oaigor vice versa? First coser that highly esecte ai scietist reset volumes o emica ata emostratig that a ercetio is mouate by sesory eurohysioogical a sycholoical mechaisms suggestig that th sa ratio o the two or aalysis is foly eg Melzac a Wall 198 Teael 997 arue qute covicgy that whle sychological actors have bee cte as be causative o ai a isaility i act sychological iculties arise as the coe quece o chroic a (see also Gatchel Poati a Mayer 995 Raaov t a 1994) a saear uo ts resolutio (see also Wallis Lor Bogu 1997 The eviece is comelligai a sychological varables aear to be like. Is there more irect evece that sychosocial actors ae extrcably ke th biomechaca actors I a recet reo Marras a colleagues 2000 ote that certai ersoaity actors togethe with some sychoocia variabes aear to i crease sial oas by u to 27% i some ersoaity tyes via muscular cocotactio. This aears to occu at moerate levels o oaig whle iomechaica oai overries ay sychosoca eects ue larger task emas This coclusio as strethee ith a iel stuy likig these geea mechaistic obsevatios ith reorte BD i worers I summary LDs aear to be associate with both loa ig a sychosocial actors a these actors seem to e relate a multiactoria The same cocusio aears to be vali or may tyes o chroic ai coitos Gamsa 990.

36

ow Back Dsorders

What Is the Significance of First-Time Injury Data for Caus e and Preventi on? One o he es indicators of fuue ack toues is a prevous histY of ak troues (Bigos e al, 199 Buron, Tloson, Troup, 1989 Troup e a, 98) Ths suggess that studes o firstime ack roule episodes may e quite revealng fo causative actors Bon, Tllotson, Symonds, e a (996 sudied poice offices in orhen Irea nd wearng >8 kg ( 8 l of ody armor n a jacket ( h s addiona o ad was o ne y the low ack  This group demonstated a shore perod of time to thei s onset of pain when compared o ofces in an English force tha did not wea he ody armor The a uhors aso  oun d that spendng mor e han two hours per day in a vehicle comprsed a sepaate risk for rsme onset o LBP Anoher survey (Trou, Main, and Loyd, 981 noed hat falls among empoyees across a variey o ndustes wee a common cause of sttime onset and were assocated with longer periods of sick leave and a greaer popensty o recurrence than wee nuries caused  ohe mechanisms. (Ligamentous damage esulting rom his type o loading is dsussed in chapte 4  I is also nteresting to noe tha pesonal fac tors appear to la som e roe n firsme occurrence BieringSorensen ( 1 984 tesed 449 men and 479 women or a vaiey o physica characterscs and showed tha those wth lage amouns of sne moily and less umar extensor muscle endurance (independen actos had an inease d occurre nce of fir stime ack troues. Luoto a nd coleagues (  995) eached smilar conclusions Muscula enduance, and no anhopomet variales, appeas o e oective Some njuies ust happen as the esult o motor conto errors (Ths interesing mechanism is intoduced in chapter 4 where we descre winessing an injY using videoouoscopy to vew the spne These may e consideed random events and ma e moe ikely n peole with poor moto contro systems (Brereton and MGil, 1999)

How Do Biomechanical Factors Affect LBO? Sevral approaches have povided evidence ino th lnks ween biomechanical facos and BD A ew are summaized hee.

M echanical Loading and L B O : FieldBased Ri sk Factors O the epidemiologca sudes tha have ocused on kinematc and kinetc iomechanica I actors, a few invesigated loadng of ow ack anaomical srucurs These would e consdered to e he sronges evidence The majorty of he studies, how ever, assessed indec measures tha ae nked to snal loading such as the pesence of satc wok postures, frequen oso ending and wising, ling demands, pushing and/or uling exetion s, a nd exerion eetio n. Whe issue overload s he cause o tssue dama ge a nd reated ack toules, these ndirect measures of oad merely ac as surrogates The attacion o using surogate measures raher han direc issue oads er se for epidemological study s ha hey are simpler o quanti and suvey n the ed owever, radeofs exis among methodological utity, ologca realty, and roustness Rsk actors related o specic issueased nuy mechansms are found in chapte 4 Seveal ssues should  e kep  n mnd when ner preing this l teatue. Viruay all reviews of the epdemiological iteature (eg, Pope, 989 Andersson, 1991) have noted that spec ic o tles and tyes of work ae associaed wth LBD (a ho ugh BD

Epdemoogca Stdes on ow Back Dsorders (BDs)

37

is defed dfferely  iffere sudies)  parcula jos chaacerzed y maual hadl of maerials sig  vrag vehices a emaiig seeaY ae al ike wh LBD. However his ype of daa does o evea much aou he lks ewee specfc chaacescs of he work a d he risk of su fferg LB D; speifially  a doseespose elaioship has o ee elucdaed. urthermore a review of 57 papes ha suveyed ow ack disorders reveae o cosisecy ewee specfi sk facors ad he deveopme of hose sodes (Ferguso a Marras 997) his eview demosraed he lae ffereces i he way suvelace was perfome ad  rsk facor measuemes. We ae emided oce aga ha ep demoloial appoaches aloe wl o elu cidae he iooca pahway of h e deveop me of LBDs  a prcess ha mus e udersoo o develop opmal peveio ad rehailiaio saeies. As oed he maoriy of specfi c sk faco s ha are addressed  he epidemio o a leaue (whch s surprisily sparse) ae really suogae facos or irec measues of spe load. hese surogae facors ae sac work posues; seae wk posures; feque edi ad wisig; lifg pug ad push; ad vraio (especaly seae). Static work postures. Reseach has suggesed ha work characezed by saic posures is a LBD risk facor While may sues have sugesed a lik wh saic wok  he key pape o hs op c was peseed y Pue ad cowo rkes  99 1 )  who eviewed  995 ack i juy cases fr om a  auo assemy pla Aalyzg jos fo r posual ad lfg requemes hey foud ha low ack sordes were associaed wh posures ha reque maag md uk flexio (defied as he ruk flexed forwar fom 2  o  5°) ( ods rao  9)  posues vovig maaiig sev ere ruk 5) flexio (def ed as he u k ei g flexed fo wad geaer ha 5°) odds a io ad postures ivoig uk wsg or laea edg greaer ha 20° (odds rao 59) he resuls suggesed ha he sk of ack juy ceased wih exposure o hese eviae posues ad wh ceased duraio of exposue Devaed posues ealy i crease low a ck ssue oadig paricularly whe he y mus e held ( Maas  Lave er a d Leges e a.   99 McGill  1997) 

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=

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Seated work postures Kesey 975 ) ked he seaed work posue o a reae sk of LBD. I a more rece sudy Lia ad coleagues 996) sugese ha al houh whe collar seea) wokes who mus s fo og peods have a reae risk of ow ack oules 8% icease i ods sk) acve ue cola workers ai some prophylac ic effec from s i dow % educ io  odds isk)  hs suess ha vaiale wok ad o oo much of ay sge acviy may have mei i reducg mehaicaly duce low ack ro ules. 

Frequent bending and twisting.he US Departm e of Laor report  98 2) ad may more sudies sum marzed y Adersso 1 98  Maras e a   995 Pue e al.  99 Sook 982) oed he ceased sk of LBD fom feque ed ad wsg I fac Marras documeed  sevea suies he iceased risk of LBD wih hgher trso veoces ( e.g  Maras e al  199 1995 ) oe ha hs is isolae spie moio a o ospecfic oso moo.) Whle hese sudes did o examie a mechasm o expai a lk wih LBD he assocaed moio wihi he spie wll e show  chape  o form a pahomechasm fo ver specifc disal ow ak disordes 

Ling, puling and pushing. he aioal sue for Occupaoal afey ad Healh epot IOSH 198) povdes a good revew likig acivies euiig lfi push ad pulig wh iceased risk of BD 

Vibration. Faly viao parcularly seaed vrao s lked o elevaed aes of LBD (e.. Kesey 195 Pope 989) 

38

Low Back Dsodes

Whe all o the sk factos noted here have een eideioogial linke with an increase incience of BD a subsequent section on tissue daae il rovde insht into the echanss inking echanical oveload the onset of an an disabilit an the natural histo of these injuries as the ertain to ob efoance

What Are the Lasting Physiological, Biomechanical, and Motor Changes to Which Injury Leads? The follown scussion of recent studies ilustrates the sustantial liteature docuenting secf erforance deicts and susequent anatoial changes n BP oulations Several stues have docuente d a change in uscular functi on afte inu ( nice su arized in Steling ul l and Wiht 200 1   These include for exa le stues o the delae onset of seciic trso usles durng suden events (Hoes an Rihason 16  that air the sines ailit to achieve rotetive stabiit duing situations such as slis and alls changes n torso agonist/antaonst activit during gait Arentie lson et al . 1 5 an aset rc usle outut urng s okinetic toso extenso efors (Grainer Koh an Ghazawi 12 that alters sine tssue oadng. Aatoical changes folowing low bak nur include asetri atroh in the ultius (Hies et al.  4 and fiber hanges in the utfius even five ears afte suge (Rantanen et al. 1 Futher n a ver nice stu of 108 atents with histories o hronc BD ranging fro 4 onths to 20 ears Shvonen an colleagues  7 note that 50% ha disturbed joi nt oton and 5% of those wt h adiatin  ain had abnoal eletoyogras to the eia sine extensor usles Fnal a ecent stud o those with a hstor o low back toubles has shown a •

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wide vaiet o lngeing defcits (McGill et had al. ineen ress. bak for troubes were of suficent to cause work oss ut the subjects ackThe to ork an average 270 weeks. Geneal those with a hstor of troules were heaver and ha distuances n the fexor/extenso strength atio and the lexo/extensor endurance atio togethe with the ateral end enurance ratio had dinishe ross lexion range of luar otion and had lingering otor diiulties coroisin their abit t alance an bend down to ick u a light object one o these hanes ould be consere to be ood. The broa lcation o th s wok is th at a hstoY o low ack troube e ven when a sustantial aount o te has elase since the toule is associate with a vaet o lingern deficits that woud equire a ultidiscilinaY intervention aoach to diinish the resence This colecton o evidence is qute oweful n ocuenting athoneuroechancal changes associated with chronic BD These hanes are lastng earsnot 6 to 1 2 weeks!

What Is the Optimal Amount of Loading for a Healthy Spine? uc interretation of the data in the edeiological iterature is lite b the fact that the levels at which tissue daage occurs eain obscure Man are conerne with the known tssue daage that occurs with high agntues o loa eetton an so on For exae Herrin an coleagues 86 found that usculoskeletal injuries were tice as ikel if the worke lubar sine was exose to oressive oces that exeeded 6800 newtons (reicted with a boechanial oel On the other han seveal o the eideioloica stues have not been able to suort a

Epidemoogca Sdies on Low Back Dsorders LBDs

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k btwee heavy wok whe cudey measud ad the sk of BD (e.. Bios t a 1986 Pot 198). Mitiati facos appea to icude epetito of sima movmts ad vaiety i wok I he dscussio of the Ushaped eaioshp betwee activity evs a LBD discussed i chapte   e saw hat st ss a optima  evs sethe s he systm whe to o ie o too much is detmea o hath Kese y ( 195 ) demos ate a eat tha expcted icease i dsc potusos amo sedetaY wokes Whi may cosde sti a o o ad task i fact it ceate s damai coditios fo th iscthe mechaism of w hich wi be expaed  chape 4 his hs oscued the emeece of a muc h cae eatioshi amo iomechaica oadi disc heato ciica impessos ad the aiity o pef om demadi wok. F uthe Videma ad coeaues (990) sudied a cosssecio of tied wokes y compai thei LD histoy wth thei MR scas A histoy of ack pai ad he vise paames of spia pathooy wee ast pevaet i wokes whose os had cuded moeat actvty ad most pevaet i woks with eithe sedetay o heavy wok. May studies compae ust two ves of wokfo exampe iht vsus heavy ih vesus modeate o modeate vesus heavy Because ay eatoship othe ha a staiht e equies moe tha two poits (o eves of acivy o eves of oai) such sudies caot iustate the shaped eatoship Coside the daa comp i a thoouh pidemooica sudy ep oted y ia ad coeaues ( 996) o f LD pevaece ad physica wok exposues. Eve thouh the authos cosideed oy the uppe eves of excess ie oadi they cocuded hat oe quat of xcs back pai mobidiy coud e expaied y physca wok exposues. Rea possiiity e mais that this is a udeesimate. uthem oe the atu of BD ap peas to e aff eced y the typ of wok Vidma ad coa ues ( 1990) oted a edecy amo t hos who had had seday ca es o have maked discasdeeeato at whe those ho had pefom heavy wok (defied ot oy iftiut asoyas equi ae tuk motios ed o have cassic at hitic cha es  he spie (steosis osteop hytosis etc  I a simia study Battie ad coeaues ( 995) epoted a appaet coiuti o of e tc f ac tos to vaious aeated chaes i the spie usi moozyoc ws ive si ficaty eate simiaities i spia chaes ha woud e expectd y chace Pote ( 98 99 2) pefomed two sudies u thei th e oio o f a otima oadi eve fo heath. he fist sudy tackd mes ad omis teat at hospitas fo ack pai Whie ifcaty moe mies epoted fo ack toub compae d with omis fic ay f ewe we diaosed wh disc potusios whi iiicaty moe wee epo ted o have steoss a d ee oo etapm et (codit ios associatd moe with he ahitic spe accodi o the daa of Videma Numie ad oup 1990) h secod study evauaed questoai esuts fom 96 paiets wh symptomatic dsc potusio ad 5 with oot etapmt yome hey wee asked about t hei hisoY of heavy wok betwee the aes of 1 5 ad 20 yeas. Siificaty moe subjects with disc potsio had doe o heavy physica wok i those eay yeas By cotast moe of those wih ee eapmt sydom had doe five fu yeas of havy wok etwee 15 ad 20 yas of ae his coctiv data suess that dffee wok demads cause diffeet spie co ditios ad pehaps ha t he optmum oad s d iffet fo diffeet tissues . No thss the optim um actvity appeas o e vaied wok a  a modeate eve twe seeta ad heavy wok What costiutes a optmum oada oad that s o oo much o oo ite o oo epetitive ad ot too pooed Cuety e ae i eed of assssmet toos fo detemii optimum oad to uide the itevetio towad optmum heah

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o Bak Dsordes

What Are the Links Between Personal Factors and LBO? Some persoa facto rs such a s muscle eurace  o streh ) a less spe ra e of moto ot more) are prophylacc for future bac troues hese ll be aresse  part III ow a Rehablao A fe other persoa factors are oe here A fe specfc persoal facors apear to afec spe ssue tolerace acor to the est leraure ae a eer are wo eamples Ja er a coleaues  9 91 ) comple the avaabe leraure o he tolerace o lumar moo us to ear compressve oa that passe her uso crtera. her results reveae ha whe males a femaes were matche or ae females were able o susta oly appromatey two thrs o he compressve loas o males. urhermore aer a colleaues ata shoe ha wth a ve eer the 60yearo se as able to tolerate oly aout two hrs o he loa olerate y the 20yearol spe. Keep  m ha ae a eer are vey smpe facors  apears ha other persoa facors such as poor moor cotrol system "ftess ca lea o a bac jY u orarly be tass suh as p up a pecl from the loor he moel ata of Cholew a McGll 996) suest ha the spe ca easly bucke u such a tas. he he muscle forces are herety low a small moor error ca ause rotato o a sle spal jot plac all be momet suppo resposlty o he passve tssues Such scearos o ot costute ecessve tass bu patets ofe report them to clcas as the evet hat cause ther jury hs pheomeo wll ot be fou  the setfc leratue however. May mea persoel woul o reor hs evet as the ause of jury sce  may jurscos t wou ot e eeme a compesabe jury hese types of jures seem to be more uece by the ftess of a vuals moor cotrol system tha by f ators such as sreh McG l a colea ues   995) oe that people er  her alty o hol a oa  her has a breahe heavly. hs s very sfcat sce the muscles requre to e couously ave o pp the spe a prevet ucl) are aso use o reathe by rhythmcally cotract hose who mus use her muscles to breathe  ths way sacrfce spe stabty hs s parulary otceable  those wth compromse lu elasty smoers emphysemcs etc) All of these efce motor otro mechasms l hehte� bomechaal susceptbty to juy or re Cholewc a McGl 996) a are hhly varable persoal characterscs. Atoal actors other tha smple loa matue appear to moulate the rs of tssue amae he mechasm of sc herato proves a eampe hle sc heraos have bee prouce uer cotrolle coos e. Goro e a. 99) hey have o ee prouce cosety Our la has bee able o coss tety prouce sc heratos y mmc spe moto a oa paers see  worers Callaha a McGll 200). Specfcally t appears hat oy a very moest amout of spe compresso force s requre oly 800000 N), but the spe specme mus e repeately eemmc repeae torsospe leo fom cotua be o a ully ee posure. he ma relevace or ths ssue s hat the ay  hch worers elect to move a e wll luece the rs of sc hera o hs hhlhts the ee to eame ho orers move  saarze tests at the be of her careers whle they s have vr acs ma  possble to eerme ause a efect Rece evece suests tha those th a hstory of bac troubles are more ely o lt fle the spe a ot the hps creas he rs o uure bac amae McGl et al  press)

Epiemologia Stue on ow Bak Doe (BD)

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What the Evidence Suppos n mmy t i inteetn  to conie y ony ome woe  become tient Tee  no qeton tt me to tie cn be ce y eceive oin n me ce n oeve n i  eception tt  mote by pycooc vie in tion to yiooic iny Cey bot yco oc n bomecnic vbe e ocite wit L n e impotnt n peventn o bc in n te enn concty; coectvey te evence fom eve cientic epective  ovewemn Te etive motnce of eite  oten ct to come co tie  te metc o ec e ife x entbiomecnic vie evibe epote neton n o ot ie pycooci eineote n newonmete oin ce ine to cyce eceton inepenent i fcto cn e compe n o tio) ome inenti epot ve noe biomecnc evence n pomote yco oci vbe  en moe i mpo nt oweve  no ty o p ycooci  vi be  been be to concvey e tbi c n ny  ociton. ome biomecnc y e te toe te it te conc pin itete e tony convincin n te etbiment o ot oction n cty Tn oone! We cn no pcee. c in j cn bein t  m e to one tie bt ti cne te iomecnic nction o te oint. Tie tee cne n ote tie become invove ein to poeve eteioton it time. Tie me oe not y et om too i  o mnte n te ce of c eton epetitive motion even in te bence of e o eem to be  nficnt ctve mecnim Te noton tt te e itin 6 to 1  wee n tt onetin wo intoence  no ptontomc bi e  be fe tie inj t n te cince of conc pin mecnim tony et oteie netnin te oe o bomecnic pycooc n eon cto toete wt te nteeto nip i b te fontion fo ette peve nton in te fte. Te cene  to eveo ve toence ieine ycooc iene n ieeve mec pctice coe. On bnce te evience o te oown ttement: •

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iomecnc fcto e ine to bot te ncence of fittime o bc tobe n benteeim n beent epioe. Pycooci fcto ppe to be impotnt  we bt my be moe ete to eoe  te te niti cete epioe. Pycooc n biomecnic fcto ppe to inence ec ote bot n tem o cton o o bence n n te coe o ecovey e etionip beteen oin n LB pe to be  e fnction it te otm oin bein t  moete eve. Lo bc tie me cn ntte  cce o cne tt my ce in n ntoence to cetin ctivtie n te cne my e iptve fo  to 0 ye in n no tnte few Mny type of tie me cn ecpe etection in vivo ven o m viibe in iection  often not viie on meic ime. T nonecific ini oe not e ot te peence of mecnc me n mt not be e to imy tt mecnic fcto e not ete to L.

42

ow Back Doder

References Aneon, B 981) Epieioogic apect of ow ack pan i nr Spine, 6: -60 Ane on, B   199  The epieol og of pina  ioe . In: ]W. Fo e E  Te adult spine: Prncips andpacice chape 8 ew Yok Raven Pe. Aent-Nielon , aven-elon,  Svae H   a Sveno, P.  19 9) The inenc e of lo ack pain on cle actvi an cooination rin ait ain, 64: 21-240. Batti e, M Han o, DR , Fhe , LD  l ,  io, L.E . an Ve an   199) Siiaitie i  egeneave finin on anetc eonace age of the la pine of ienical tin. Joua ofBo n a ndJoin uge 77-A 1662-1670 Bieing-Soenen F 984 Phical eaeent a k nicao fo ow-back tle ove a one-ea peo pine 9: 106119 Bigo S], Battie, M, Spenle DM, Fhe L, Foce, WE, Hanon H, acheon AL a Wote, MD   199 1  A popec ve  of o k pecepton a pchoocia l facto affecin the epo of ack inj pine 16: 1-6 Bigo S]. Spenge, M, Matn NA, Zeh, A Fihe L Nacheon, A, an Wang, M 96 Back inie n int A etopectve  II In faco pine  : 246-2 Bogk,   De, R , Api,  , Lo, S  an Scha ze R  996) Peci o ia gnoi i n pna l pan In: a pe ]. E.), Pain 1996A n updaed eview pp 12 Seatle: IASP Pe Beeton L an Mcill SM 1999) Effec of phica faige an cognitive chaenge on te potentia fo o ack i Human Movemen cience 18: 89-85 Brton A , Son , L  an Znzen E ., e a  1996 I egono c interv enton a lone  cient to i clokeleal poble n ne Occupaiona Medicin 47 25-2 Bon A , Tlloton, M  Son L, Bke, , an Mahew on,   1996 Occp atn al i k faco fo the fit oet of ow ack ole A t ervng police offce. pin 21: 2621 Bon A. K. , Tilloton, K M  an op, D   1 989 Pei ction of ow ba k te f eqen c in a wokn poplaton pine 14 99946 aahan ], an Mcill SM 200) Ineveebal ic henaton: Stie on a pocine oe epoe o highl epeive exon/extenon oion with copeive foce. nical BioechaniC 16 1 28-7. hoewicki ].  an Mcl , S. M. 996) Mechanic al tait of the n vivo l a pin e Ip ication fo inj an chonc low ack pan. nica Biomechanics 1 1 (1 11. Delito, A ., Eha, R E , an Bown RW  995 A teat ent-ae caf icat on appoa ch o ac te ow ack noe: Ienifin an taing paient fo co neat ive teate hyical Tap, : 40-489. Fegon, SA, an Maa W.S 997 A leae evew of low ack oe eillance ee an ik facto inica Biomechanics 12 4): 21-226. Foce, W.E. E 99 Backpa in in he wokpace. Seate: ASP Pe. Foce, W.E 996) Repone to Thopon/Meke/Teael lete ain, 65 1  2- 14. aa A  1 990) I eotonal tat a pecipitao o a coneqen ce of pain ain 42: 1-19 atche R] olain PB an Mae,  99 The oinant ole of pchoocia ik faco in the eveopent of chonc low ack pain ait. pine 20 2702-2709. oon S Yang, H Mae ]. Mace A.H.]., Kih, vl an Ra n L  1991  Mechan of ic pteA pelin epo. pine 16 40-45 6. ane, M  Koh T. ]. , an hazaw A .E. 992) ecopln of biatea eci aon i bec t ith lo ack pain. pine 1: 219-22. Hale , N.M. 99 1) Ining again wok ncap act f o pina o e In: ] W F oe E. ) Te adu spine e w Yok: Raven Pe  Hale,  2001) Etoal The ane of the aging woke pine 26 2): 109-10 Hen  A  Jaaei, M , a n Aneon   1986) Pecio  o f oveeetion nie ng bi e chanica an pchophcal oe A meican Indusia Hgiene Associaion Jo ! 47 22 0. Hie, ].A ., Stoke, M .].  Sa e M  Jl  A, an oo pe, DH 994) Evence of ba tif  cle ang iplatea to pto i paie wth acte/ace low ack pain pine 19 16177. Hoge, PW. an Richaon, A. 996) Inefficient cla talizaio of the a pine aociae ih lo ack pain pne 21 : 2640-260

Epdemologca tudes on Low Back Dsodes (LBDs)

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Hdgs, PW and Richardsn , C. A  1999 Atered trunk musc rc rutment in ppl th l back pan with uppr im mvement at diffrnt spds A h f ha Md ad Rhaba 80 100-1012. Jager, M, uttmann, A and au, W  1991  umar l ad durin nhand d bricklaying. aaua fdua Eg, 8 261-277 Jnssn H Brng, G., Rauschnng, w halstedt B   1991  Hidden cerv cal spn nuris in tra ffic accdnt victims ith sku ll fracures  ua fa Dd 43: 21263 Klsy   197  An pidemil ical study f the relatin ship tw n ccupati ns and acut hrniad lumar intrvrtera dscs aaua fEd 4  97-20. ira,  , hannn, H . , Chamers, .W., and Haives TA  1996 ng trm ac k prbl ms and physcal wrk epsurs n the 1990 Ontar health suey A ra 'ua fu b Hah 86 3: 382387 rd, M , Barnsly  , Wal is, B , McDnald G  , and duk, N  996 Prcutaneus radifruency neurtm y fr chrnic cervical zygapphysea j int pai n N Ega du a f Md 33 17211726 ut, ., Hliraar a, M., Hurri, H , and Aavanta, M 99 tat c back endura nc and th rs k f l back pain a Bha 10 323-32 4 Marr as, W . Davis  KG , Hean ey, C A, Mar nits, AB., and Aread, W.G.  2000  h in unc  f psychscial strss gnder, and prsnali n mchanical adin f th lumar spin.  2: 304304 Ma·as, W, avendr, .A. , eurns, .E. , et al.  1993 The re f dynamic t hre-d nsnal trunk mtin n ccupatinaly rlat  ack disrdrs The ffcts f wrkpac factrs, trunk psitin and trunk mtn characteristcs n risk f nury  18 617-628. Ma"as, W ., avender, . A., eur ans, E. , Fath ala h, A., Feru sn S.A., Alr ad WG, and Rajuu, . .  1 99 Bmechan cal risk fact rs fr ccupatnally related l  back disrders g 38 377-410 McCal . W., Park, W.M. , an d O'rin, P.  1979 Inducd pan ref rral frm pste rir umbar  l mnts in nrmal subjcts  4 441446 McGill, M 1997 Th bimechanics f lw back injU mplicatins n currnt practic in indust and th clnic  ua fBha 30 46-47 McGil  .M  t Grenir  S., eects Prus s,nR.psychscia, P. and Brnphysilgica, S. in press)and Previ us hist ry fcharactristcs. BP ith rk s s is rlated ngring bimechanical McGil .M , Sharratt, M.. and Seguin,  P  199 ads n spina  tissues durin simutanus lfti ng and ventilatry chalnge Eg 38: 17721792. Mlzack It and Wall, P..  1983  hag fa  Ne Yrk Basc Bks Mendelsn G   198 2 Nt cued by a verdict ff ect f a ve sett mnt n cmpnsatin claiman ts Mdaua fAua2 29-230. Natina l  nstitute f r Occupatina l Safety and Hath (NIO H).  1981  Wk a gUdf aua g Dpartment f Hath and Human Serices (DHHS), NIOSH Publicatin N. 1-122 Nrma n, R. , Wels, R , Nu mann, P, rank, P, Shannn, H., and Kr r, M.  998) A cmparisn f peak vs cumulatv physcal wrk epsure rsk factrs fr the reprting f lw back pain in th autmtv ndust. a Bha, 13: 6173 Ppe, M.H.  1989 Risk indcat rs n l  back pain. Aa fMd 21  387- 392. Prtr, RW.  1987 Ds hard w rk prevent disc prt sin? a ha 2 96-98. Prtr, RW.  19 92 Is hard wrk  d fr th ack T h reatinship betwn hard wrk and w back pain-related disrdrs aau a fdua E  9 17160 Punn tt  , ne ,  Kyrserlin WM, Herr in, G D , and Chaf in D.A.  199  Back dis rdrs an nn-nutral trunk psturs f autmbi assemy rkers. adaaua / k E ad Hah 17: 337-346 Radanv, BP, Sturnger, M, DeStfan, G and Schinrg, A. 994 Ratinship btn ay smatc, radilcal cnitive and psychscal findings and utcm durin a n-yar llw up in 117 patients suffring frm cmmn whiplash Bh ua f Rhua 33: 442448 Rainvil, ., bel B. Hartian, c an Wrg ht A   1 997 he ef fect f cmpnsatin invlvement n th rprting f pain and dsaility by patients referrd fr rehabilitatin f chrnc w back pan.  22 20162024. Rana nn,  , Hurm, M , alck, B. , et al.  1993) The umbar multif idus muscl fve years aftr surg fr a umbar intvrbral disc herniatin  18: 6874

44

ow Back Dsodes

Scwz A W S Dscll D i T, u N d L R (995  bliy  cm my  iiy  iul zyysl ji i is wi lw bc i ine 20 (8) 907-92 Si  Lid K Aisi 0. d M i  (1 997) Mm  disu bcs   lumb si d bml bc mscl lcmyic iis i c w bc i ine 22: 289-295. S    Clss  PG   b     ( 1998)  y  llw-u c ms   c s d ciss  cicic  ysiy s imy mm   bc i ine 2 (7 875-1884. S  S  ( 982) Lw bc  i i ius   Wi AA d Gd  L  ds siu n iihi w bk i n S Luis Msby Sli M  ull G  d Wi A  (200     c  muscls ll i  m c iiy  d cl jn Pin 2 (): 15-145 yl ] wmy   C M (990  d s issu ijuis i ps-m lumb ss Pegi 28 119-129 sll RW (1 997   il  c c i jn Pin Reeh Mngeen, 2: 89 91 sll RW d Si AP (1998 Wls ijuis A  j Pn Resech Mngeen : 8190 ms Msy sll yc (99) Ls ublis i Pin 5: 11-14 u ]D G  m  K    C     w D  ( 1987)   p ci  bc i d  l  syclic ss  li cciy ine 2: 45-57. u ]DG Mi ]  Lly DC (1981) c i i usyA psci sudy ine : 19 S Dm  b (1982) c iuis ssci wi ii (ull 2144 Wsi DC G m  Pi i c V H  cs  L , Siy M A   l  198  li shi   i p ci  lmb  isc dii s s by C/iscpy ine, 12: 295-298 Vidm T Nmi  M   u ] D ( 1 990) Lmb si l l y i cd ic m   i li   is  bc i cci d yscl li ine 5: 728-740 Wdll  G ( 987 ) A w cli cl mdl   m   lw bc i in 2: 2-44 Wdll G ic M ilys D d Mi C (984) Symms d sis Pysicl iss  illss bi? rih Meiju289: 9-741. Wddll G McCllc ]A Kummll  d V, M (1980 Nc sis i w b i ine 5: 1-125. Wlis   d S M    N ( 1 997 Rsli  sycl icl dis ss  wils  is lwi m by icy umy A dizd dbl-blid lcb clld sudy Pin 7: 1522 W M d H  D  ( 2001 ) Clizi pm  s  p sic c  chic lw bc i d disbiiy ine 2 (7) 787. Wi AA d Gd SL (982) Sysis Wsh  idiic w bc  e 7: 14 149 ili vR d McGi ll SM (2000 Ai s  sil mi sms  Kimi cs  ics d suli ijuis bsd i  ci ml ine 24 ( 18 1882- 1889

Functional Anatomy of the Lumbar Spine

T

he aerae reader o thi ook wl hae aleady tudied a anatoy o the pne Th hapte egin y retn oe anatoa eatue, poily in a way not preouly ondered Then thee eatue wil e reated to noal ntion and nuy ehani to ay the oundation or the peention and ehaltaton tate ie that olow  eee that lnian and ientit alke who peiaize n o ak troule do not deote uient eor to iply oniderin the anatoy The anwer to any queton reeant to the nian an e ound withn an anatoal raework The ehania oundation or peentin and rehaltatn ak troule  ontained hee pon opetion o thi hapter you wl undertand the pea anatoial ea tue that hae untona eleane In additon you will hae a ette undertandin o injuy ehani whih wl help enue that you do not unknny inlude nuyexaeratng aneue n therapeuti exerie perpton

Te Vertebrae A you undoutedy know, the pne ha twee thoai and ie lua eterae The ontrution o the ereral odie theele ay e likened to a arrel ith round wal ade o elatiey t orta one ee ure 1) The top and otto o the arel are ade o a ore de orae ailage plate end plate) that i approx i ately  6  . 00 n.) thk ut thnne t i n the entral regon (Roet Menae , a nd Uan,  The end plate  porou or the tranport o nutrient uh a oxygen and luoe, he the inide o the arrel  iled wth anellou one. The traeu lar aaneent within the anellou one  aligned with the tre traetoe that deeop durin atity Three orientation doinateone era and to olque (Galoi and ]apot 92 ee ig ure  a)

5

Tansvs pocss

Pdc Spnos

Tan svs pocss Info a tca act

amna

no aca pocss

_ Spo aca pocss

Accssoy

� ansvs pocss Vba foamn

Spo acla fact

Spo atcla pocss

Tans vs pocss �

Mamlay pocss

amna

Accssoy pocss

 no aca act

Spnos pocss

Figure 4 Th parts of a typal l mba vtba Image cortesy of Prima Pictres.

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Figure 42 Th arangmnt of th tab ula (ist otd by Gal ois and Japot i  925) s alg nd wth t h domant tators of stss. Th th tab uar systms a s how in G,  and .

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nconal natomy o th  mba pn

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Vertebral Architecture and Load Bearing Th very spial arhieue o he vereral bodies deerins ho hy ea opressve oad and ail under exessive oadin. The alls o he verea (or sids o he barel ) eain rigid up on opression u h nul eus o he ds pessuris (h lassi ork is by aheson 160 66) and auses he arainous nd pls o  vebrae o bule inard seeiny o opress he nelous bone (rinkann Biann and Hilwe 18. In a under opression he anelous bon ails rs (Gunning Callaghan and MGil 200 aking  he derinan o lu oerne o he spine (a las hen he spine is no posiioned a he nd ran o oion). I s diul o inur he dis annulus his wy (annular aur ill b disussed le). Ahough his noion s onraY o he onep ha h verebl bods a riid he unonl nrpraion o his anaoy suggss a very levr shokabsrbin and loadbrin syse. aran 973 proposd he noion ha he verbral bodis a as shok asorbers o he spine alhough h sed his mo on vrtbrl bdy uid o han on ndpl ulng.  suesed ha h dss re no h ajo shok asorbrs o he spn onra o virually any exbook on h subj ine h nulus is an inopressil luid bulgin end plaes sugs luid xpulsion o he vrebl bodis speiially blood hrouh he priverbal sinuses (Roa 960 his ehanis sugess a proive dissipion upn quasisai and dynai o pressive loading o he spine. Moe verebra odybasd shokabsorbng ha niss are douened subsequenly In sumay he oon san ound in any xbooks ha h diss are he shok absorbers o he spine no ppars quesonab l rahr  he vr ral odies apper o pla y a doina n roe in pe  in hs union

Uderstadi g Vertebra  Mechacs To ruy ppeae verebra behavior  enouage you o oan a verbra ro  buhr (bovin or poine is idal) old he vereba end plae  nd pl been your hub and iner and squee.  you have nevr don his bor you il be aazed by he deormaion and elasity. Th vreb xpernes siilar doaion as he inopressib nuleus o h dis prsss ovr he ntral end pla during spne ompression in vivo. Deormable verebra is a n noion or any. o d h end pas bul ind ino seeinly rd bone? Th ansr appers o b in h rhur o h anllous bone Verbral anellous bone sruure is doned by  sys o oluns o bon (shown in ure 42 ha run verally r end plae  end pl. The verial ouns ae ed oher ih saller ransvse rabeula pon xl opresson as h end plaes bulge no he verebrl odies hse oluns xperiene opesson and appea end. bony Underransverse xessiverabeul opessive load h bndin oluns will bukl as he o saller raure as dou end by yhri nd Shaler 994 see iure 43 n his y h anllous bon an rbound bak o s orgnal shape (a las % o h orina unodd shap wn he load is rovd evn aer suing aure and delinaion o he ransvers ( rbeu la). Thi s arh ieure ap pears o  ord xlen ela si doraion even a arkd daage and hen o reain is oriinal sruu and union as  hels Daaged anllos aurs appar o heal quikly ivn h sl aon o oseoni aivty nedd a leas hen ompared ih he lnh o ie nedd o rpair ollaenous ssues.

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ow Back Dsordrs

Moraung o he rabulae an our th epeiie oading a leel ell elow th  il ure lel o a n yle o load u and oaue 2001 deonaed that yl oading a 10% o uiate ai lure load aued n o daa or han in i ne ut wh 20,000 yle o oad a 2030% o the uiate ailur load, oh tine and enery orbed a aiue wee dereaed ghly repiti load, en at quie low agnude appr o a us irodaae he oeoporot ertebra i h aatrid by in Figue 43

eral o and deinin bone deny in th treulae Beaue raner tauae are  ew in nuber han longtdinal aeulae and baue hy are generally o aller diaer, h trnsre r eula e piial ly ar h a re or ehnl o proie h oteoooti inea los (ila and Rernted from  Vo 1 51 ), Fyrie and Sceffe Gion, 17 (ee igure )  nteretnly, the a "Fae mecans ms in man vertebra canceo s bone 1 01 09, oyrgt 1 994, wt emssion of Esevier auhor nod a highe ndeny or the transs Science taeulae to diaear n ale with rater ni dn thn in als hs los in ehanial inegrity o the ranee raeulae has  rea inuene on he oprsi trenh o th eae i th hani debd arlie. hus, th oteooroi erbra bins to lowly olape hn expod o exe e load with eri buklin o he oun o bon uiatey d eloin he a de h t i nerin to ontrt h a  othe exree o he one denFigue 44 Wth agi g, the tras verse o horiont al tabeclae th ad y petru The transre tr eventally os e ther a bilty to spport the vertic a trabeca e, which ca n eula hated o spins then bucke, casng verteb a colla pse. () A healthy tab ecular bon e who prored hay ork (in netwok fro m a 7yeaod woman .  erfoato n  a hor izontal tabe cla in a n edery woma. aiu r, eihli r r thk erinted from  Vo. 21 Siva and Gibson,"M odeing te mecanica beavi or and dn In addiion, here h of vertebra trabecar bone ffects of age-reated canges in microstrctre," 1 91  tranrs traeula intrsd 1 99 oyrigt 1 997 wit ermission fom sevier Science ith the ertil oun th join ere harateized with hay ony useting, iilar to ha  ldr would wed o strenghn a righanled oin Th ranere rabulae pr o e ruil in dtrining opree rngth  anohe oseed au ehani o the ertebrl body  terd the so

Under compe ssve oadng bulg g of the ed plate cases b ckl g stresse s i the vetcal trabecu ae whch wh en excessve causes damage in the tasve rse tabecua e. Note the vetcal from compresson) (A) ad hoiota fom tesio) B cracks i the tasverse trabecuae.

uh" in whh extenie trabuar daa is obeed ithout onoitnt lo o ins o abrupt hane in the loadeortion relaonhip (Gunnin, llhan nd MGill, 200 (ee gur ) Sne op hange n th oadoraion reltionhip i oen used to identy the yield oint, or he inil tiue d hi nju an o unnotied Intrtiny nough, rbrae ailn undr ernrsn opssi oad ill radu al y nra in i nss, a tetan to the ondrul arhit tur o the tanr and erta taeula Alo intereting i he lodrt depndn o one tr nh a h  nd plate ap par to ai  ir  lo load rt hil h rtral ony lent a at hiher load rt (ee iur 6

ncto nal natomy o th mb ar pn

49



a

igue 45

Mve rb eul r dg e ound d rg e d ieon nd reov o  o w olow ig  exeive "ow uh opeive od ). ige gniion o e  e i ow in  ve t ive tue w o le o  y or y other exio n ehod . Reprinted wit permssion of  Gunnng,  aaga n, and S. McGl , Clal Bomhas 1 66, 200 opyrgt by evie Science.

N= 14 e < ( C

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 ( ( o

' 

N  10

N= 4

N=6

N=8

80 60 40 20

100



d pl at

1000

3000

10000

16000

d at (N/s)

Vbal body

gue 46 opreo inure  diferen od te A low e o opeve lod e end plte ppe to be e t ue to  i, bt boe wil  tre i t u de ghe rte o o d

ot  is an t vrtbra for i supporin spina loas. nr xssiv oprssiv oain t bulin of  n plas int t v ral ois also auss raial strsss in t n pla suiint to aus ratur in a stlat pat (s fiur 4.7 Ts ratrs or ras in t n p lat ar sotis o allo t vrt iui nulus to squirsufiinly tou lar n plat in t ral body Gill  1997 (s urs 4 an 49.  tis a loal ara of on olapss unr t n plat to rat a pit or ratr tat s on to r t lassi or's nod (s iur 40 ab Tis typ of injy is assoiat wit oprssion of t spin igue 47

Seltep eed edple  dited w row) ou  the u opeve o d, whi h u e it o blge he end plte, i pg ten e ee

eu i  pe uized de 

5

ow Back D sodrs

Nc

Figue 48 Une opeve long e n le  preize ing e en pl e o blge i no e veebrl boy Wi exeive rilenie e e en ple wil   e n e vio n le wi l   og e rk i no e veebrl boy

Figue 49

ollow ng  oe eve e en ple r e,  porion o e n e   i e rog ino e veebrl boy own  e p o e lpel n e ow}Ti i  poine peien

Figue 40 In ion  o enpe  re, oe inrie o e en pe ner opeve lo nle "p ," wi o   b lr bone re in  l e ne e en pe () Tee go on o or Sorl' noe A So' noe i own  e ip oe row n  Adated, by ermis sion from iradyWi  is and Buton, 1 983, Maagg low bak pa, 3d ed (New York Chrci Liingstone, 72

hen th pne  n the neutral rane of oton .e not fexe bent r tted In y experen ts type of pre njury  ery oon and oftn danoed as a ernatd d due to the flattened nerdal pae een on planar X rays Hoer note at n enplate fratre the annulu of th  reans ntat.  s ply a ae of e nuleu lan te d and proren trouh the nd plat nt th anellous ore of th ertebra oete efrrd  a a ertal a tn Oer he yars we ha preed oer 00 pnal unt n a neutral potue an all but two rsule n ndplate fratue a the praY tue aa

nconal natomy o th mbar pn

5

Ed-Plate ractures I y experiee edplae frare wi e lo of lear id ro e ra io e vereral body ofe for Sorl' ode) i a very oo opreive ijry ad perap e o idaoed Lo of e d le rels  a flaeed erdal pae a we ee o plaar X ray  ally diaoed a a eraed di or deeeraed d" owever e al of e di reai ia ' iply a ae of e le qi ro e ed plae ra io e aello ore of e verera Tre dis eriaio reqre vey peial eaal odiio a will e deried orly We o prei pie i e la we ear a adle pop" a e ia of edplae frareexaly a paie repor we ey derie deail of e eve a reled i eir pai I alo roly pe a oe frare are oea be i a o iediae evere pai os Oer owever ay be i aeoly ae  deped o e bioeaal ae a aopay e frare If ere i aial lo of e le fro e d ie i i verially eiaed e iediae lo of di ei ad beqe opoie of erve roo pae will rel A i poi e edplae frare will ii e ypos of re eriaioaoer reao for e oo diaoi

Posteio Elements of the Vetebae Te poerior elee of e veerae pedile laae po proese ad fae jo ave a ell of ial oe b oai a aello oy ore i e i eio Te ravere proee proje laerally oeer wi a peror ad a iferor pair of fae joi ee fre 4 O e laeral fae of e boe a for e peror fae are e aesoY ad aillaY proees a oeer wi e ravere proe re ajor aae ie of e lois ad lioos ali exeor le rop dered laer) Te fae oi are ypial yovial jo i a e arlai rfae are overed w yale arilae ad are oaed ii a aple Firoadipoe elaree or eioid are fod arod e r of e fae alo oly a e proxial ad dal edes od ad Eel 984 w i ave ee iplaed a  a poile r re a old bd" ad lo e fae jo ee fie 4 ab). Te eral ar i eeral pedle ad laiae appear o e oewa flex ible I fa Bedzii 199 deosraed exiliy of e p  dri exio/exeo of adaver pie wile iey ad olleae (1996 doeed p o reederee ae of e ri pedile wi repe o e lef pedile dri qie ild daily aivie i pedile rew i vivo Falre of ee elee oeer i fae daae leadi o py are oeies laed exlively o aerior/poerior ear fore However a ae old be ade fro epideioloial evidee i alee  a ya ad Aralia rie bowler ardale Aear ad Foer 199 a e daae o ese poserior elee ay alo be asoaed w fll rae of oio. Te yi fll pie flexio ad exeio  ee o of aiviie fae e ar wi repeaed re reversal O e oer ad ere i o dob a exeive ear fore ae iry o ese poerior vereral elee oerior ear of e perior vererae a ead o lieo daae  alo failre i e veerae ielf a e ed plae ofe

52

ow Back Dsords

Spns pss

Inf aa pss Pxmal d

Dsa d

a

Sp ata pss

da sd

aa sd

f ata pss

an

pss

 igue 41 tel view  te n rticl process () reveng te cet, e brodpose  eniscods , nd e dpose i sse pd, wc ve been p lced in  ont b nd ng . oss secton o te posero vi ew o te ce o nt  sowing te posons o te ib od pose enscoids nd te dp ose isse pds i n e on.

al om t  t o t  ta o igi g a MGi    igu .2  Bot ou la oatio a iuio it itatioa o lagu a rio ou up tat ti t o ailur ma b mo ommo i t aolt a giati pi ta i t oug a mia ault pi. ur ok i  o ormatio Cripto a olau 1) oumt tat atrior a o t uprior rba au pa a at ratu laig to ooiti wit a tyial tol a o a ault ubar pi o apoximatl 000 N. Atoug imi la ijury maim a tol ra au w ob i oug orci pi pim iglig a MGi 1a, ) t yp o i apa to  moulat  oaig rat iiall, atri a o ou uia ot tiu iju at lo loa rat 100 N/) ut ratu o t ar  at a a ta bo r o at igr oa rat 000 N/. otio ar or appi at lo loa rat pou u al ot tiu ailu a t al o ratu wil to or at igr oa rat ru w ratu a at amag. il ar tolra o t tbra motio uit apar t  i t ra o 00000 or otim loai Nma a olau 8) oti a i ra i rot ak pai i io i o tat xpo ork r to rtiti ar oa grat ta 500 N  oir t t t guili ur rt aailab

igue 412 Ser in es nc lde cre o  e cet bse nd, on occson, endpte vls on ro e verebre 

Functonal natomy o th umbar pn

53

The Posteio Eemets of the Ve tebae Ae Fexibe  dertadg Veera Mea  o page ,  eoeded otag a verea fo te uter Gap te vertera ody  oe ad ad te woe eura ar  te oter Bed te ar up ad do ad ote te flexiiity Ti flexura dpaeet ou  ea ye of fu pe fex io/exteso oo  evet u as oe's gyati ee figure .3 f t yg otiue te tre evesa   evetua y aue a fatigue a  te pars Furer repetto wi aue te a to propagate troug te fu widt of te pa evetuay esutg i fatuead  vvo, te odito of spodyoite igue 413 epett ve gynti ove    ti  e tetn eve in te p In ient n  be tey wi et n  tig e te-edng to pondyl ot ei

Neura Arch Factue podyoiste ad eua ar defet are ede ag feae yasts ad riet owers to ae a few atiet wt spodyoitesi geeray do ot do we wit teapeut exeie tat tae te pe troug te ae of otio rater taity oud e te eatatio oetive  ave ee i voved  tato ae  w ea spodyoiste exted ut wa aeed to e reated to a peif evet fo exape, a eety ourrg autooe aidet)   urgey owever tere wa evdee of usta tia oteoe i ativity sugget te uy wa quite od  fat, tese patet foe gyasts ust ave ad t daage we opetig ut were o it ad teir spes so tae tat tey were ae to ea i opetitio Foowig reteet av dre, ad oi fte a ater ior evet eae te tiator of teir ypto

Intervertebral Disc e iterveera dis a tree aor opoets: te ueu pupou auus fosu ad ed pate Te ueu a a geie arate wit oage fr upeded i a ae of ater ad varou uopoyaaride gv t ot visosty ad oe eat repoe we pertued  vto At te ri of soud rude te et ay to de e a eaty ueu i tat it oo ad fee  e eavy pe ui ivito tetg we ave ad it quirt out ude preure ad teray st to te a Wie tere s o dstt ode etwee te ueus ad te anuus t aeae of te auu eoe ore ditit ovi radiay outward. Te age fe of ea aa are oiquey oieted te oiquity u  te opposte dire tio  ea oet aea Te ed of te oage fer aor ito te

54

ow Bak Dsorders

eteal ody with Shapey' fie in the oteot laellae, whie the inne ie attah to the end plate the end plate wa died in a peio etion) he di in o etion eele a onded tiane in the thoai eion an an ellip in the a eion etin p ailitation of twitin and endin

oad-Bearing Abilities The di ehae a a hydotati tte that allow ix deee of otion etween eteae It aility to ea oad howee depend on it hape and eoety e to the oientation o the ollaen fie within the onenti in of the annl with one ha of the ie  oliqe to the othe hal f the ann l i ale to eit load when the di i twited Howee only ha of the fie ae ale to ppot thi ode o loadin, whie the othe half eoe diaed eltin in a tantia lo o tenth o aiity to ea load he annl and the nle wo toethe to ppo opeie oad when the di i jeted to endin and opeion nde pine opeion the nle peize applyin hydali oe to the nd pate etialy and to the inne annl atealy hi ae the ann ol laen fie to le otwad and eoe tened ea ao aof and oi 94) eleanty deontated that a di with the ne eoed lot heiht t peeed h of it popetie of axial tifne eep and elax ation ate he fat that the nle appea neeaY to peee di heiht ha ipliation o faet loadin hea tif ne and liaent ehani It i notewothy that di daae i ot often aopani y dial one a ae Gnnin Callahan and Gill 200). In fat Kelle and ollea 993) noted the intedependene of one tat and di health Reent eidene alo et that exeie opeion an lead to alteed ell etaoli within th nle and in eaed ate of ell death apoptoi) Lotz and Chin 2000) h the eidene et that inolin lowe opeie load tilat on notd a a opeie oelate of loadin di health) t that exeie loadin lad to tiehealthy adown

Progressive Disc Injury Conideation o poeie di injy i in ode hee A noal di nde opeion defo ainly the end plate eially toethe with lee otwad lin o the annl inann ieann and ilwe 988) owee if little hydotati pee i peent a in the ae in whih the ne ha een lot thoh ndplate fate o heniation the ote ann e otwad and the inne annl le inwad din di opeion ee ie 414 a) hi dol onex lin ae the lainae of the annl to epaate, o delainate and ha

a

ige 414



 n  helthy on t with  conned n cle  ee  mi ni m nn   deomion n der compeive od   the nc le loe pree ( de o n endpe c e, or exmple) e n nl  comp ee, cng dil bgng bo otwd nd inwd (row nd podcng delminng ee  e nnl lye re plled pt

Funona naomy o he umba Spne

55

een ypoteszed as a patway for nuear aterial to lea trou te aellae ayers and finaly extrude reatn a fran ernated dis Adas an olan 199) Anoter interestin proposal as een reently put fort y Professor Adas personal ouniaton) He as suested tat a ealty is uilds intea pressures uner opressie loads tat are so  no nee or asular essel oul suie Folowin inita enpate daae te dis an no oner uid sustantal pressure su tat neres and lood essels are ale to inade te dis. ese are ore possilites to expain te inrease asularization of deenerate" diss an teir ailty to enerate pain Fr a reie w of te literature one an a e four enera onusons a out an nu us inj an te resultn ulin or erniation: . It wou appear tat te is ust e ent to te ful end rane of otion n order to erniate Aas an Hutton 98 . Ds erniaton s assoiate not only wit extree eiated posture eter fully fexed or ent ut also wit repeate oadin n te neioroo of tousands of ties litin te role of fatiue as a eanis of inY Gordon et a 991 Kn 993) 3. Epideiooa ata n erniation wt sedentay oupations an te sittin posture Videan Nurinen an roup 990) In fat Wiler an olleaues 988) douente annular tears in youn alf spnes fro prolone siuate sittn postures an yli opressie oadin e siulated tru rin) 4 Herniations tend to our in youner spnes Adas an Hutton 98) enin tose wit er water ontent Adas an uir 976) an ore yraul eai or Older spines do not appear to exit lassi extruson of nulear ate ral ut rater are araterize y deaination of te annuus ayer an raa ras tat appear to proress wt repeated loadin a nie reiew is prie y Goel onroe et al. 99). A ouple of years ao we sout te ost potent eanis eain to is eiation. Gien tat it was ritia to reate a ooeneous oo of speiens we ose a pi spne oel ontroln diet  pysa atiity eneti aeup is deeneration an d so fort. W found tat repeated flexion otion under siultneous opressie oadin was te easest way to ensure erniation In fat it turned out tat te nu ers of yles of flexion otion were ore iportant tan te atual antude of opresse oa Wle no erniatons were produe wit 60 N of opressie loa and up to 8000 flexion yles erniations were produe wt 867 N of loa an 000 to 8000 yes and wit 1 N an only 000  900 yes Callaan an Gill 001)

iure 15 ehbiliion devi e uh  hi  em o i ote m b moon b y exendi ng gint  eine  d bu ee im utneo lmbr omeion . We ound h eli ing the u l rnge o moion  om ul  lexion o net l nd ung he omeive l od o thee deve were oweu ombntion t o odue di heni ion

Clearly erniations are wt a funtion repeated fullof exon otion yles only aofodest lee aopanyin opressie oad n fat we ied te luar otion an loain of a typal spine reailitaton aine were te seate patent elts down te pelis to solate te luar spine and ten extends te torso repettiely aanst a re sistane oer te da.  Anazinly soe people are trained on tis type of aine een tose wit nown is erniatons!) See fiure 1) Te tie

56

ow Bak Dsorders

Fgure 417 Figure 46 Seril rdiogrph owin g he  niil onine o he r dioon  he ueu nd, w epe ed u lexion oon wi bou  0  o opreio), e pogeiv e poeor rkg o e or u  k ero.

Repeed lexo  eu n  rk herii on or  blge, ow hee   peen wih he  i n reoved o expoe he poeior d, wh n pnge on eve i g ypo . Noe h he nu e w eed w  dye o   e bl ge i ore vibe ro w)

Rented from Cial8iomhas, 1 61 ),.. aagan and S.M McGi "ntevertebra disc ernaton Std es on a ocine mode exosed to g y reetitive fexion/extension motion wit force" 2 2001 wt ermisson fro m sever Scence 

sis rdgrphs (s igur 46) dmnstrtd th prrssin f th ulr mt l trcking thruh th nnulus ith sucssiv mtin yls. h hitd dis s t rsult rm cumultv trum: vn thugh  hv crushd l vr 400 vtbrl mt smnts, w hv nly n r tic bsrvd  hnit ithut cmitnt xin cyls Nt tht  r inclung bth rk hiti d vis ibl  dsc  ulgs (s fgur 17 und r this ctgy  ij mhism As rth ntin hr is th ntuin  duk d my h hv suggstd th ssibility  n nnurhythss sri similr t  sri  th nkl lgmnts Bduk nd wmy, 199 Thy hypthszd tht th utr lyrs f th nnulus xrinc xcssiv stri ud tsin Gvn tht ths uthrs hv prsntd vid fr th prsn  nrv rs ptiully i this ri th nuus pprs t b  gd didt r  surc f .

Mecha sm s of A ls aue (He atio ) Dm t th nuus f th dis hitin prs t b ssit ith fully lxi th spi r  rptd  prlngd rid  tim  ct, hii  th dsc sms lmst impssil ithut ull lxin hs hs impictins  rcis rsiptin rtiulrly r lxin strtchi d situs r r tivitis suh s rn sittn l  hich r hrctrizd by  xd sin m sistn xrcis mchs tht tk th spi t u fxi rptdly must b rsidrd f ths itrstd in spin th pstrir nulus prtins  thir diss

Metho do logi cal Coce s fo Testg Spie Motio Uts Cnusins dr rm xrimnts prfrmd n spi mti uits r imitd by th hc  xrimt thniqus A f  ths ssus r disussd hr.

Position (Angular Rotation) Control Versus Load (or Torque) Control Th us f pstinl vrsus ld ntl wh ldin vrtbrl mti uits hs b htly dbtd r yrs (.. Gl Wldr, t l.,995 Th issu  th hrt  ths mthdlil dbt is Whh mthd mr lsly rlits inviv

unonal naomy o he umbar Spne

57

ding ? h use f p sitin nrl (..  a lad ae  500  /s r 16 in ./s in h invi stdy ineased he pailiy  pduing n intervrta  s h and sl  m sv s h  xsin. This is due  the shap f th lddtin elainship, hih is hihy nnlin, pgessin rapidly t  vry seep final prtin, nd n d ue his is   urrn in eal lif. Ths nsn viy ding psiin nr suls in vey apid inrass in ld in th steep rin. Trqu ntrl e., a ld rte  00 N/s) prvd t e less daain nd wld  e e prsenta tiv f the inviv esuls u nd y Ms nd Grant 199) n ddiin, tq nl uld ply et reprsn pssil pttiv ehaniss prsnt in th dy d t inesd in tatinl siffnss.

s an Anmal Model Usefulfor Human Applcatons? While huan advri atria has pvided  elth  infrin in th ar f spine inj y, yn helthy hun spines ar xteely rr Typial dnrs  ldely nd sik; ynger dnrs r ith sik r had sustaind sstania vilnt taa. This is an iptant isse s ailue pats in th spin  a funtin f ilgil ge F xap, der dgeneratd diss r less susp ti t herniatin Ads and tn, 1982) rndeing the unsitale  in vstitins  herniatin ehnis. Otinin athed yung, hahy hun spi ens r ntr lld stdy siply is nt a rali y F these asns, e hv hsn t se prine ia spines in liu f hun ur spines in ny expeients Prine rvial spins prsnt a hlthy hene s sapl e f speins, spi ay prviding sintii ntrl vr geni akeup, age, ight, physial ativity levs and dit. Whil n tld expients re ny pssi sing anial dls, he vius liility is ht  rlevan fr ppiatin  human ehanis and thpdi  prisn an th geetria, antial, and ntina aspets f th prine ervial spin nd hn lua spin sggss they r reasny iehni y siia i ning, Callhan, nd Mil , 1999)  hav q s tined he se   quadupd ervil spine. Whie pis ar qudrpds suppting th weigh f the head and addiinal lads ipsed y usla tivity reqied t leverae the antilevered head esuls in sustantial prssive ds n h pine ervial spine see ig 418). This lad eing pprs   quite anagus  tha  he huan uar spin. The ipda han rvia spin, hwver, ds nt have t ndre th es fr ninual exns n train, givn inial tqes, as he head sits n tp  the spine in the upight pstr Nnehless, an nial prepa rtin rains  del r he hn spine and t se pin ust e ited and sad r hn ppiatin. ige 4 he pig spe s es y s r rhie ur e ures w h he  u  b spine oside e sl lodbe rig eureens Te iev ered drped ek s desiged o ber rge opressive oe s op) due o e exensor s le ores () eeded o suppor e wegh o e hed in  hs posre , ogeher w l i ied rge o oon. ese e s r o e dends ped o e h  l br spie wen bedg owd o e ven us sdng

58

ow Bak Dsord ers

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Muscles Traditoa aatomcal descriptos o the spie musculature have tae a posterior vatage poit. This has hideed isght to the role o these muscles sice may o the uctoaly reevat aspects are ettr viewed i the sattal plae o a ice syopsis o the sa gittal p ae les o acto, see ogdu 980 Macitosh ad o gduk, 987. urthemore may have deveoped their uderstadi o muscle uctio by simply itepetig the lies o actio ad regio o attachmet, assumi that the musces act as staightlie cales This may e miseadig Udestadi the uctio ad purpose o each muscle requres to perspectives. owldge o Secod, static muscle morphoogy is essetia, though t may chge over aFirst, rage o moto. owledge o activatiotime historis o the muscuatur must b otaied over a wde variety o movemet ad loadig tass Muscs cret orce ut these orces play oles i momet productio or movmet ad  stail  joits or saety ad perormace. urther uderstadi o th motor cotrol system strategis chose to support exteral loads ad matai stability rquires the terprtatio o aatomy mechacs ad activatio poiles This scto ill hace the dscussio o aatomically asd issus o the spi muscuatur ad wl bled the resuts o vrious electomyographc studies to hep itrprt uctio ad the uctioal aspects o motor coto

Muscle Size h physiologic crosssectioa area CA) o muscle determis th orceproduci potetia, whil the lie o actio ad  detrmie the eect o the orc i momet productio staiitio, ad so orth It is eroeous to stimte musce orc based o msce volume without accouti or iber ahitctur or by takig trsvrs scas to measure aatomical cosssectioal areas McGill, a, ad Nora, 1988. s  areas directly otaed rom CT or MR slices has led to erroeous orce estimates ad itepretatios o spie uctio  such cases sice a lae umber o muscl ibers r ot see i a sigle trsvers sca o a peated muscle, muscle orces ar uderestimated. Thus, areas otai rom MRI or CT scas must be octd or i architctue ad sca plae obliquity McGill ataguida ad teves 993.  igure 9 trasvse scas o oe subject sh ow th ch  shap o the torso muscles o ver the thoaco uma egio highlihtig the ed to combie trasvers sca data wth data documetig iber architecture otaed dssectio  ths ex ample, therom thoracic xtesors o ssimus thoracis ad iocostas lumorum see at T9 provide  extesor momet at L eve though Figure 419 rve e  o one bet pne) t te level o,    Lnd  owng te mlte n roeton Note tt mny m e ee t moe peo leve p tedo ove te lowe leve tmitting ore  i l trte te eror  i mply ing   ng le n to etimte mule or e d momet potenti. Rernted from Clnal Bomhans  S Gi  L Santa guida and  Stevens," easure of te trunk musuature from 6 to L5 using R sans o 1  young maes ore ted for mus e fibre orientation"

1 71, 1 99, wit ermission fom Esevier Siene.

Functional Anatomy of the Lumbar Spne

59

they re not seen in the L4 scn. Ony their tenons overlie the 4 etensors. A sgittl plne schemtic shows the error s in mesuring muscl e crosssectionl re rom  singe trnsverse slicewhich hs cuse some to unerestimte the potentil o the muscle. Rw muscle physi ologicl crosssect ionl res n moment rms McG ill, ntgui n tevens, 993) re provie in ppeni A.1. Ares correcte or obliue ines o ction re shon in tle  or some selecte muscles t sever levels o  the thorco umr spine. Guielines or estimting true physiologicl re s re provi ed in Mc Gil n collegues 988. Other recent sources o rw musce geometry obtine rom MR or both mles n emles re oun in Mrrs n colegues 200 Moment rms o the omi nl mus culture re gene rlly obtine  rom CT or MRbse Generlly sujects or prone within the MR or Lying CT scnner n thestuies. istnce rom their spine lie to supine the muscle centroi is mesured. on their cs in this posture cuses the bominl contents to collpse posteriorly uner grvity McGil, J uker, n Aler, 99 6 n rel lie n when stning the omins re pushe wy rom the spine y the viscer contents Recently, reserch hs shon tht C/MR stuies o the ominl musce moment rms obtine rom sujects in the supine posture unerestimte the true vlues y 30%. In summ unerstning the orce n mech nic potenti l o musc es requires n pprecition or the curing line o ction which is est otine in the ntomy lb But unountely these specimens re usully trophie eliminting them s  source or musce size estimtes Muscle res otine rom vrious meicl imging tech niques nee to e correcte to ccount  or iber rchitecture n contrc til e components tht o not pper in the picur scn evel or emple only the tendon psses the level. Further moment rms or musce lines o ction rom subjects who re lying own nee to be juste or ppliction to upright postures mintine in rel lie.

Table 4. 1

Corrected Muscle Cross-Sectional Areas

A ew ex am es o corr ece d cros s-sec ona  areas, aneror/ oseror momen  a rms, an d aera momen 

arms erendcar o e msce er ne o acon s ng e cosnes  s ed  n M cG , Pa, and Norman (1 988). Tes e are e v a es a sod e sed  n omecanca  m odes raer an e  ncorr eced vaes oaned d ec rom sca n sces.

Cro-ec ona area (mm )

ce

omen arm (an/ pos ) (mm)

ome arm (aer a) (mm)

ongssms ars morm*

3-4

644

51

17

Qadra s m orm

 1 2

358

31

43

2-3

507

32

55

3-4

582

29

59

4-5

328

16

39

Exera oq e

3-4

121

Inerna oqe

3- 4

1 1 54

1 10

17 20

89

*Te lin e o ong i u pr l u boru   e L lev e wold ve been ed here by vi re o he r oie b were o ,  hey oud o be dingi ed o l l n  lie

60

ow Bak Dsorders

Muscle Groups Th cton dcr cc muc gou om  unctonl ctv nd nto duc om u undmntl o undrtndng njury vodnc nd th choc of rort rhtton och.

Rotatores and Intertransversar Mny ntomc txtook dc th ncton o th m otto mul o th n hch ttch to djcnt vtr,  ctng x ttng toqu Th  contnt th th nomnctur rottor). Smlrly th nttrnvr r otn nd th rol o ltrl lxon Th rool hv vrl rolm. rt th ml mucl  ur 2 hv uch mll hyoocl croctonl  tht vo ou oi

vo o bvi

oo

v dili tv t

igue 420

Sho sl es o the spe: levo ost  oi, evo os   bev, etsvese edis, etsvese ltel is, ot oes, d  tesp lis hey h ve bee des bed eo eosly s e xl twisi toe mag coutsy o Prma

Pictrs

Funonal naomy o  he umbar S pne

6

they can genera te on y a few newton of f orce and econ d they work throgh c h a ma moment arm that ther total contriton to rotational axia twiting and ending torqe i mnimal or thee reaon I eleve they ere another fnction The rotatore and intertra nverarii mcle are hgh y rich n mcle pind le approxi matey 4.5 to 73 time more rich than the mltid t and eck 986). Thi evdence gget that they may fnction a length trandcer or verteral poiton enor at every thoracc and lmar ont. In ome G experiment we peormed a nmber of year ago we indwellng eectode very cloe to the veebrae n one cae we had a trong   cion that the electrode wa n a rotator mcle The bect attempted to perform iometrc twitng eort wth the pine ntwted or contrained n a netra potre n oth drection t prodced no G actvty from the rotatornly the al activty in the adomnal olqe and o on owever when the bect tred to twit in one directon with minma mcar eort) there wa no repone whle n the other direction there wa maor actvty Thi paclar rotator eemed not to be atvated to create axia twiting torqe t rather n repone to wited poition change. h t actvity wa elicited a a unction of twited potionwhich wa not conitent wth the roe of creatng torqe to twit the pne Th  tronger evidence that thee mcle are not rotator at al bt fnction a poition trandcer n the pne pprioception ytem.



Maa Theapy ad the cto of the Rotatoes ad Itetasvesai We now pect that the rotatore and ntertranverarii are actaly lenth trandcer and thereby poton enor ening the poitionng of each pinal motion nit. Thee trctre are lkely affected dring vario ype of manal therapy wit the oint at end range of motion a potre ed n chiropractic techniqe for example

Extensors: Longissimus, Iliocostalis, and MultidUS Groups The maor extenor of the thoraolmbar pine are the longim iiocotal and mtfd grop Althogh the ongim and iliocota grop are often eparated n anatomy ook t may be more enlihtening in a unctional ontext to recognze the thoracic porton of oth of thee mle a one grop an the mbar portion a another rp The mbar and thoracic poron are archtectraly ogdk 980 and fnctionally dfferent cGill and Norman 98). ogdk 980) partiton the lmar and thoracic portion of hee me nto long im thorai par lmboru and par thorac and iliocotai mborm par lmom and par thora. Thee two fnctional grop par lmborm whch attach to lmbar vertebrae and par thorac which attach to thoracic verterae form qte a maelo archtectre for everal reaon and are diced in a fnctona context wth th ditncton .e. par lmborm v par thoracic). iber typing tdie note difference between the lmbar and thoracc ection: the thoracic ecton contan approXimately 5% low twitch fiber whle lmbar ection are generally evenly mxed (Sirca and Kotev 985). he par thoraci componen t of the e two mce attach to the rib and veeral component and have reatively hort contractle fer wth on tendon that rn parale to the pne to their srcn on the poterior race of the acrm and medal order of the liac cret ee figre 4) rthermore ther lne of ation over the lower thoracc and l mar region  t  nderneath the facia ch t hat force in thee mce have the greatet poe moment arm and therefore prodce the greatet amont of extenor moment wth a minmm of compreive penalty to the pne ee fgre 4 When een on a tranvere RI or C can at a mbar leve par thorai tendon have the greatet extenor moment arm overyng the lmbar blkten over 0 m 4 in) (cGill att and orman 988 993) ee figre 43)

Figure 4 An iole d bud e o ongi u thor r  thor (i eg on h e rib  t wih edo l ted by obe, oure ove he u lu b e to their rl o g. hey hve  v ey lge exteno  oe  O u underneth the 

Figure 4 hi wor ld owe le exelie he hyerohied b uk o he lioo d logiiu  ue een n ined lie r h u le bu l i in he ho egon, bu he endon n he enire ub ne

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no on

Figure 4 3 he oen   o he 

ubo u ortion o liootli nd logi iu A  d B he lrge oen  o the r hori l iooli nd longi iu  ule () gve he he biy o e te o r  ubr exteor oe he lie o ion o he  u boru oo o longi u (D)  he r u bou oion o liooli (E d he  ho ortio o ogiu d iooli F oi  he o on o o src  he l ine he ehnl ulru o he xi bout whih  ule re e oe  indied by he dod he G)

62

unonal naomy o he umbar Spne

Fge 424

Ilocos is  mbom  s lm bom nd longiss ims orcis rs lmborm src ine over he osero sr ce ofe scrm follow  very seficil wy, nd hen dve obl iely o e verebr  chmens his oble oien ion crees oseio she (S forces nd exenso momen s on e c sccessve seror veebe he comressive xs ( C) s indiced

63

The l  cpnens f hese sles l islis lr ps l nd lnssis thrcis ps l e vey dfferent nticlly nd fnctny fr hei thr nes es. They cnne   he il ly ccesY nd trnsvese pesses f the  ver ee nd inte ne in ve he pster sc nd edi spect f he l est Ech vere is cnnected lterlly ih sep rte line f hese ses see fie 424) Ther lne f tn is n prlle t th e pres sve xis f the spine  rthe hs  pseir nd d drecin h cses the t ener te psteir sher frces ether with extensr ent n the speir vertere see fie 425 These pster sher fces spp ny neir ectin sher fces f the pper vetere h re prdced s he ppe dy i s fexed f rd in  ypicl lfng psre  s iprtnt  ri ht ths flexin f he trs is cpshed hrgh hip rn n l flexn These ses lse hei lie line f cn nd rer  ent  he cpressve xs f he spine h l r le xin M il l, H ghsn  nd rs 2000 s h  exed spne is nle  resis din sher frces (see fige 4.26 d This psse njry echns tgehe ih cvtn pr-

fes dng cin iclly elev nt civtes s ddress ed n  lter sectin. The ltfids scles per ie a diffeent fnctn fr thse f he lngisss nd ilicsis ps priy n the r re Fge 425 e obi e nge of  e l mbr in where they ttch psteri spnes f dj oions o f ongissims nd ii ocosis re s een in cent verere r spn tw   the e seents (see vivo n his M  c e hei lin e of force F s shown relve o e comessi ve xis (C) . fire 427. Their lne f tn tends  e prl lel  the cpressive xis r n se ses rns nterirly nd cd l n n l e ir tin The jr ehnicly relevnt fee f he tdii, hever s th since they spn nly  fe jints their fres ffect nly lcl res f he spine. Therefre he tfids sces re invlved n prdng extensr tre ethr th ve sll nts f wisin nd seending e  nly pvde he ili ty fr r ecins  ent sppr t specific j ints th t y e the f ci f sesses. nterestiny he lifds sles ppe  hve ie l sce spn de ensit yce nly less  hn the ilcs tlis  r lngisss s ces A n fi 983. This y e de  heir re edi lcn nd sseen sller lenh excsins (see e 53 fr sce enth hnges whh we ssessed sng  ner f extree psres ht e depiced in fgre 51 n pe 9. An ny echns nvin nppprite nerl tvtin sinls t the lifds s ppsed in chper 5 sn n exple f n seved in the lry. I s s wrh nin here, iven the recent ephss n ltifi s, ht se pepe hve cnsdered re le pins f the exensrs  e ltifs. T hs hs presened se prles n  h fntnl n erp reti n nd rehittin.

a

b



d

Fge 26

e obl iue ge o  e l b poos o he i oostis l bo d ogiss s o s potets e spe gist rge erior sh e ore s Howeve, his b iy i s  uo o spie  vre  A eut spie (a) d the ob ue ge o these s es s v ewed wit  rsod ge  e loss o this gle with spe exio () so th teo s er or es o be ou terted (d).s es ues she sblity d i s other eso o osider doptg  eur spe d rig exed wegodg sks

ige 27 Midus s uly  se ies o e t t  sp oe o thee verte br segets  e li es o o do ot sppor  eror se o he sperio veebr e b tuy oribue o  xi g e  rossseo re evels h the u lidus is  eively s l  br exteso  oo

64

oi

mage outesy of Prima Pctures

Tale 4 .2 Muscle Lengths i n Centie tes (In clud ing Tendon Length Otained Fo Upight Standi ng Position and Fo V aious Extee Post ues * 25 latea  ending

0twst

274

300

 7 7

326

30.5

229

55

 3 3

1 8.0

 92

1 5 6

95

 62

 82

1 2. 2

76

1 00

22

1 2

69

9.5

 07

Upght stadig

60 flexio n

R e s doms

30

1 98

L e s dom s

30

1 9.8



67

44

26

L ee oqe 

67

44

2 3

R ee oq

 5 8

 29

07

1 2. 9

2 0

R ee oqe

e 2

b b

the

L ee  oqe

2

 5 8

R e oqe

1

1

99

9

L e oqe





99

4

R e  oqe

2

 03

88

76

L e oqe

2

 03

88

32

b b b b

b b b

Comed"

b

b

b

b

(L 

51

200 b

42

 5 4

 87 b

L so s m om (L 

15

200

68

57

207

R sos mom

25

1 64

18

 29

1 5 6

1 2 5

1 64

 38

 30

 70

(L3

99

1 29

95

00

1 2 5

L so s m om (L3

99

 29

09

98

 33

R so s m

om (L4

75

94

74

76

93

L so s  mom (L4

75

94

80

74

9.5

R ooss mom

230

297

89

235

264

L ooss mom

230

297

255

228

38

R so s  mom

(L2

L so s m om (L2

R so s mom

b b b b b b b b

b b b b b b b

b

continued

65

66

Lo Bak Diorr

ud

Table 42

Uprigh saig

60 flexio

R ongm orac

75

337

L ongm orac

75

337

R qadra

1 6

 B

  mom

b

b

b

25° ae a eig

 0 wis

omie"

5.

76

3.

BB

7

3B

 l 9

1 

9

b

b

L qadra m

orm

1.6

B

 7

15

09

R am do

(5)

9.

3

6B

9B

9.0

L am dor

(L5)

9

3.

315

9.1

36

5

5

7

5

5.5

7.5

50

51

70

5

5.1

7

b

b

R md



53

73

L md



5.3

7.3

R md



5.1

7

L md 

5.

7

oa (L  )

9

B.6

B

90

7

L oa (L1 )

9

B6

30

95

96

R oa

(L)

5B

5.3

5

57



L oa (L)

5B

53

65

60

6

R oa

(L3)



B

17

0

1 

 oa (L3)



lB

5



3

R oa

(L)

 B7

 B6

1 B6

 B7

 B.

L oa (L)

 B7

1 B6

B9

 BB

 B9

b

b

b

b

b

R

*e nge o exree posures sed o ssess sle leg ges s ilused in igure  o ge 91 ·ob in ios o 0° lexio, 25° g lel bend 1 0° oeowise wis  Ms le eg s  die by oe n 20% o ose ob ned d rg upri g sdng Repinted by pemission om SM MGi 1991 neti potentia o the umbar tunk musuatue about thee othogona oho paedi aes n eteme positions Spine  9(): 091 5. ©Lippnot Wiiams and Wikins

unonal naomy o he umba Spne

67

A Note on Latissimus Dorsi tissius drsi is invlved in lub exten sr ent genetin n stbitin due t its rigin t ech ub spinus prcess vi the lubdrsl sc nd insein n the huerus see igure 28 Durng pulling nd liting tin, the ltissus is ctve see chpte 5), hch hs iplictns r its rle nd h it is trned r unctn tin ptterns

igr 428

i dor oigne ro eh lub inou roe  vi he l u bodol   nd iner on he huer u o e or boh l b exenon nd bilzon oe mage ortesy of Prima Ptres

Lmbodosa fasca

ass i m us dos i

Exercse for the Extesor Musces of the Low Back Reserch hs shwn tht the thrcc extensrs (lngissius thrcis prs thris nd ilcstls lubru prs thrcis) tht ttch in the thrcc regn re ctully the st eicient lur extenss snce they hve the lgest ent s s they curse ver the ub regn. F this resn, it is t ie t revisit t he clinicl prctice  islting uscle gups" in ths cse the ur extensrs r th lubr spine Speciiclly, wht re reerred t s the lub extensrs (lcted in the lubr regin) cntribute nly  prtin  the ttl lubr extensr ent rining  the u extensr echnis ust invve the extensrs tht ttch t the thrcic veebre hse bulk  cntctle ibers les in the thrcic regin ut hse tendns pss ver the lubr egin nd hve the gretest echnicl dvn tge  ll ubr uscles  hu s, execses t iste th e lubr usces cnnt be justied r n nticl bss nr r  t cntrl pespectve n hich ll plyers in the rchestr ust e chlenged durng trning (ntnued)

8

Lo   ore r

ne mpran cncal ssue nvves e anamcal eates  te exen ss. Wle e mar secns  te lngssmus and cstals msces ta atac t e umar verebae ceate extens qe, ey als prdce ae pser sear ces  sppr e seang lads at develp drn rs exn pstres. Sme erapsts nknwngly dsale ese sea rce pec trs y avng patents uly ex ter spnes drng execses, creatng y  qescence n ese muscles, r by ecmmendn e pelvc l drn ex ng acvtes suc as ltng. scssn  s nctna anatmy s crtcal r devepng te stateges r njuy prevenn an d reatatn descred ae n s bk

Abdominal Muscle s n s sectn we wl cnsder several mptan aspecs  umar mecancs n c e abdmna muscles are nvved

Abdominal Fasa Te admnal asca cntans te ects abdmns and cnnects lateray  e apnerss  te ee ayes  te admnal wal. s nctna sgncance s made me mprtan by cnnectns  te apneuss wt pectals majr,  gee wt ascal eements ta css te mdne  ransm ce t e asca and admna msces) n e ppse sde  te abdmen Preed and eRsa, 18) see gure ., ab Suc anatmcal eaues ndepn and jsty execses detaled ater a ntegrate mvement paerns at mltanesly callene e admnas, e spne, and e slder msclate.

Reus Abdominis We many cassc anatmy exts cnsder e admnal wall  e an mpran lexr  e tnk, te rects abdmns appeas  e e mar trunk lexand te ms acve dung sups and cups ker et a., 18) Musce actvan ampludes taned rm b ntamuscuar and srace electdes ver a varey  tasks are swn n tale  pae 3) It s nteresn t cnsder y e recs admns s partned nt secns rae an ben a sne n musce, ven tat e secns sare a cmmn neve supply and at a sne n muscle wuld ave te advantage  radenng te celengt reatnsp ve a greater rane  leng cane. Peaps a sngle msce wud lk pn stenng, cmpressng te vscera,  e s and ressan  endng t nly des te sectned ects admns m bukng upn stenng, ut e secns as ave a ead eec, c allws endng at eac tendn  actate s lexn/extensn r adm nal dsensn r cntactn as te vsceral cntens cange vlme M elaner, nversy  Qeec a Mntreal, persnal cmmncatn, 16) Te eaded recs als perms ante rlete latera ransmssn  rces m te blqe musces rmng a cntnus p and e admen Pered and eRsa, 8). Te nemuscuar endns and asca pevent te es  ecs m eng rpped apar aeraly m ese p sresses Ts aspec  admnal mecancs s elucdaed uter n e nex secn, wc dscsses e rces develped n e que muscles. Ane cnca sse s te cntversy regardng uppe and le admnals. We te lques ae regnally actvaed and ave uncnal separatn etween pper and lwer egns, al secns  e recus are acvaed teter at smla leves durng exr trqe enean. A sgncan unc  nal separan des n

Functonal Anatomy of th e Lumbar Spin e

Exenal abdomnal obiqe msce

Aponeurosis of extenal

abdomin a obque

I

Anterio layer of ecs sheah

Aponeurosis of inena abdominal oblique

Recus abdomns muscle Linea alba

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Intena abdominal obiqe msce Tansversus abdomns msce

ansvesal s asca

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Rcs shah

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Rcs abdomns

Innal obq

Exnal oblq

b

igu 429

e abdoa asc a conecs e obles o e abdoal wa w rectus abdo s (a ad, to a lesse ext et, ectorais ao ad e s to ans it oop stesses aod e abdo e 

ppe to es eeen ppe n loe ecs Lehmn n Mcl 200 n most peope Resech  eences n he pp e n oe ctvon some tmes ses omepotng he sence o nomton o the M sgnlecs ng pocessng Bey eseches hve se  mples o myoelecc cvy n mlvols to concle ht hee s moe o ess ctvty eve to othe secons o the mscle t the mgnes e ecte y loc concvty chcescs Ths, ptes ms be nomle to  stne contcton n expesse s  pecenge o ths ctvy he thn n mllvols see ge .0. Reseches my lso hve nvetenty monoe pyms n oponl mscle t he se o he ects hch ol co ne peton

ow Bk Dsords

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ig 430

Sdes h hve epo red n ppe nd lowe ecs bdom n s genely evle d n nom ed EMG sg nls-or e xmpe, n he sdy o men pe orm ng c nche s However, when he s gn s e nom ed popely, h e ppr en derence d sppes  Wh e here e egon cvon ones n he bdom nl ob es, here s  le evdence o sgges h  nconl pper nd ower re cs bdomn s exss n mos peop le Rerinted b y ermssion, ro m G ehman and S.M McG 1 999Journal o Manipulative Physiological, Therapeutics.

r and Lower Rects A distnct uper nd lower rectus does not exist in most peole (though some indviduls my hve the ily to reerentily ctivte one section slghtly di erently rom he other in select ctvties). hus trining the rectus c n e ccom plshed ith  singe exercise. his is not true or the oiques s they hve severl neurl compmentslterl medl upper nd lower

Abdominal Wal he lyes operorm the dominl (externlAlolique olique trnsversethree domnis) severwll nctions. three ntel re invoved in nd lexion nd per to hve their lexor poentil enhnced ecuse o their ttchment to the ine semlunrs (see igure 4.31) McGll 996) which redirects the olique muscle orces down the rectus sheth to eectively ncrese the lexor moment rm. he oliques re involved in torso twstng (McGil 991 1991) nd lter end McGil 1992) nd er to ply  role in l umr stiltion since they incre se their ct vity to  smll degree hen the spine s lced under pure xil comression uker McGill

unonal naoy of he uba Spne

gre 43 e obue ses EO eror oo o exel obl ue; 0 eor oo o ierl ob l ue; sve rse bdoi s) rsi oe og e iber egs d e redre o re og res bdo is vi e  he o e l e sei lu s o ehe eir e eive lexo oe  Reprinted from Journal ofBomechanics, 2(7) S.M McGi, "A revised anatomica mode of te abdomina muscature for toso fexion effots," 73-77 1 6 wit perission from  sevie Science

7

nd Kp 18) This uncinl ntin  l e develped  n this chpte.) The iques re ls invlved n hlned lung ventiltin ssstng ith ctve expirtin enke et . 88) Th impn untn impl itn   ctiv xpirtn il e discussed n  susequent sectn. Resechers hv cused  lt  enin n he trnsvrse dminis r tw resns. Firs sm eeve i s invved in spine stity thrugh its eltike cninment  he dmn nd ls in he enerin  intdminl pressur AP. Rchrdsn nd cllegus (1) nicly summrizd th secnd sn  the cused tentin n this mu sl its n recuitment during llstic rm mvemns n thse ih crnic lw ck cnditins. Specic l y studes reveled th trns vr sus hs  delyed nse  ctivtin time n ths ith ck rules prir   rpd m mvemnhe hyphsis ein ht he runk mus irst  mde st nd se N du ths is eviden tht n errnt m ptrn exiss in rpid ctivity; hever the questn remins s  hether ths s imp nt in mre nrmly pced ctviies. Delyed ns nirms mt deis u  10 t 3ms ns et dely ul d e irl evnt durin  nrml mvement in which these musces re cninully cntced t ensue stility. t is ls intesn ht cnt  ppur thught he trnsversus nd inern ique re very smilr in he ier rienn. n u vry imited intrmusculr EM eectrde k uker e . 18 e s  high degree  upling etween hese t musls in  wid e viety  n nllis ic exerins n  du  sm my-

eletric crsstlk existd). netheless sevr gups Csse nd leues 1 nd dges nd Richrdsn 6 r the mst experenced) hve ntd the exr ivy  tnsver sus when AP s eleved. The cminn  trnsvrs tv in nd lmst lys cncmitnt liqu civty) with eved AP nhnces sity ithut quesin. n ct Chlewicki nd cllgus (1) reny cnluded ht uildin AP n its n dds spine stility. In th rder unc inl pespetive t he cmpnents   h dmin s (recus  liqus nd rnsversus) wk eher u ls indepndnly. While  vrety  suces hve prvded myeecric evidence rm  vriety  sks n ntmcl unctinl nterprettin s needed As nted erle he lques derentily civte  re ising trqu nd cn enhne xin rque. Rctus is pimrily  xr in t hse pple h hve  et del  mtr cntl in the dmn s cn peeenilly cive ech musce see igue .3  thuh d). Finly sm hve susted n uppe nd lwe prttining  th dmins. As prevusly men ined this impressn is prly n rtic resultin rm p electmyrphi

echniqu nt pper t e nd  unctn uppeOn nd nd Mclthee 001des Verrci enie Mcll 000). hler herectus hnd Lmn rinl dierens d exist n the iq ues; sme secins n e pre erentilly eud h medlly nd  tely gether th upp er nd lwer pins. Fnly the l iques ethe th trnsverse dmns rm  cntnng hp und he ent d men ih th nterir  he hp mpse d  the dmin  s nd t he pseri cmpsed  he lumdrs sci. The resutn hp sresses nd stiness ssist wih spine stily.

72

ow Back Dso drs

a

b

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

Soe eds people hve bi ly o di eeiy speciic po o h e bd 432 hs Figue scure seuece hows (a)  the cve bdoil wll, ctvte he bdo l wltos "bllooed," doil  coc io o tsverse bdo i is, wh ch dws d "ho lows" t he wl. Plcg he hds o he hig hs d pus hi g (d) ows  lexo oe to develop whee good u sculr corol s be to civ te  s he ecus bdoi s wh the pevousy ctive d tsverse d  tle ob iue ctiviy

Abdomial Musce Exercises The uncn divsns  he dminl muscle usiy he need  sevel eecise echniques  chlenge hem in ll  hei les mmen genein sine sbiy, nd hevy behng While he lques e egnlly cived, ih seve neu cmmens hee es  be n uncin sen  ue nd le ecus dminis Thus,  culu eecse cves l tns  he ecus dminis. eve ue nd e ins  he biue bdminl musces e cved seey deending n he demnds ced n he s Finly deiled eminin  he scil cnnecins eves ce nsmissin mng he shude muscuue, he sine nd he bdminl muscles, usiying eecses incng lge mvemen ens  he d vnced iens h cn be he hihe lds.

Psoas The ss  uscle h csses he sine nd hi, s unique  mny esns While  hs been climed  e  m sbize  he lmb sine, I believe h his cm needs neein. lhugh he ss cmle ches  2 nd  eveY um veteb n is cuse ve he elvc ing (see gue .33), is civin

toa atom o t  mb a Sp

73

pril (s Jukr MGil nd rpf,  Jukr, MGl r  . 1 nd Andrssn,  . 1 fr indwlin MG d is n nsisn h tht   sn stilizr in th urst sns ut rhr indits tht th rl  th ss is uly s  hi x r. Du rin ur wr k t imln i ntrmusulr ltr ds in th s musl  w prfrmd th insrtin hniqu svrl tms n uslvs. Th irst tim th lds r in my n ss  trd svrl w k xrtins tryn t vt it nludn fxin xtnsin sid ndn .. n f hs rly usd th ss t fir. mpy risin th l wh stnding with hip flxn usd mssv tivtin lry indting tht th ss is  hip xr. Aftr this it rk n  rgr study w und tht ny sk rqurin hi lxin invlvd th ss. Althuh w tind this imprssin frm sudyn h tiv in pril  th ss thr nsidrtins stm frm its rhitur. Why ds th pss trvrs th ntir lumr spin nd n ft urs l th y t h lr thri sin? Why n lt  ust th ius rfrm hi xin f nly th i liu s wr t flx h hi h pvis wuld  torqud int n ntrr plv tilt rin th lumr spin int xtnsin. hs ors r uttrssd y th pss hih dds stifnss n h plvs nd th umr sn n  it n  thuh f s  sin stilizr u ny in th prsn f ignint hip xr trqu. Als n ivd nd stifnd ss will ntriut sm shr stffnss t th lumr mtin smntut n in nly hn hi xr trqu s rquird. Th  is tht th ss nd ilus r w spr musls s ntguid nd MGill 15 untinlly rhitturlly nd nully Thr s n suh thin s n iiss mus! n ddtin sm linil disussn hs n ntrd rund th issu f hhr h ss is n inrn r xtl ottr  th mur/h. Alhuh t hs sm

lac ct Figue 4

Qadat lmbom

Poa majo

Tanv poc

e po e o eh ub vereb (ler verebl body nd nvee poe) wee e o hee line o po ue nd o  oon endon h ou e hroug h e l iopein el n oh o e  e r he d lu boru he e h nvere proe wh he r b nd  li re,  or ng e gy wre uppo ye mage cortesy o Prima Pictres

4

ow Bak Dsordrs

rhitturl vntge t externly rtte th hip, Juker, Gill, Krp t l. 99 bsvd nly sm ll tivtin bi s uri ng hi p rttin tsks. wever this my hve ben u t th ned r signiint hip stbiliztin resulting in substntil hip ntrtin. n  reent study e exmind  mthd h  wrkrsh o hm hd  histy  disblin w k trubles whil the thr hl hd nevr missd wrk. Thse wh hd  histry, but wr symptmti t th time o the tst, hd  signiint ss  hip extensin nd hip internl rttin but mr extrnl rttion. This is n interestin bservtin, given muh ini disussion rerdin th tiht" pss Even thugh e d nt lly understnd th neumhnis, this musl s  lini nern is rth studyin urther

Psoas uctio yltri evidne nd ntomil nysis suggest tht the psos mjr ts primrily t lex th hip tht its tivtin is minimlly linked t spin dmnds nd tht it i mpses substnti lumbr spin mpressi n hn t ivtd. Cutin is dvised whn trining this muse u t the substntil spine mpressin pnlty tht is impsed n th spine whn th pss is tivted.

Quadratus Lumborum The udrtus l umbrum  QL is nthr spil musl or sv r rsns. First th rhitture  this musle suits  stilizing role by tthing t h lu mbr vrtbr etivly uttressing jent vrtbre biltrly tgthr ith tthmnts to th plvis nd rib  (se igu 433 piilly the ibrs  the QL osslink the vertbre n hv  lrge trl mment rm vi the trnsvrs press tthments. Thus, by its dsin the QL ud buttress shr instility nd be eetiv in stbilizin ll ding mdes Typilly under mpressive ld th irst md  buklin instbilit y is lterl (Lus n Brs ler 961 th QL n ply  signiint rl in lol trl buttressin. Als, th QL hrdly hnes lngth duin ny spin mtin (se tbl 42 n p 65 nd Gil 199b) sugsting tht it ntrts virtuly ismetri lly. Furthr insiht int its spi ntin mes rm n rlier bstin tht th mtor ntrol system involves this musl tgether ith th bminl ll hen stbiity is ruird in the bsn  mr mment demnds Th musle ppers t be tive durin  vriety  xindminnt, xtnsr dominnt, nd ltrl bening tsks. te tht myletri ss t th QL is uit triky, nd it is diiult t nirm where th inrmusulr etrdes r ithin th musle Certinly ur tehnius n this musl wre nt vry prise. n dditin, they tend t mirt upn ntrtin, her ludin interprettion o th sinl Andersson nd ollegues 99 un tht th QL did nt relx with th lumbr extnsors durin the lxin/relxtion phenmenn. The exin/rextin phnmenon is n interst in tsk sine thr re n substnti lterl r twisting tus nd the xtenr trqu pprs t b supprt pssively urther suesting sm stbilizin l or the QL n nother expriment nt in tht our lbrto thniues t btin QL tivtin er rthr impreis t th time subjets std upright with  buket in eh hn. We inrmentlly inrsed the ld in h bukt (rsultin in prres sivly mre spin mpressin. Our dt suggst tht the QL inrsd its tivtin lvl (tether ith the lius s mr stbility ws ruired Gill, uker nd Krp 996b. This tsk rms  spil situtin sin only mprssiv lodin is pplid t the spin  in the bsn  ny bndin mmen ts n s umm, the str nth  th videne rm severl prsptives leves ne t nlude tht th QL prrms  vry speil stbiliZing rle or th umbr spine in  wid vriety  tsks.

Funconal naomy of he uma ne

75

Qadats mbom The quadratus lumrum appears t e highly nvlved with stailzatin f the umar spne tgethe w ith the muscles suggestin g that a clin ical fcus f this muscle s waranted ercises emphasizng actvatin f the quadratus lumbrum hile sparin the spine are desced in the rehailtatn sectn

Muscle Summa This sectin has prvided an vervie f the res f the muscles f the tunk in suppting pstures and mvng and stailizng the lu mar spin e The pste ir musles were presented in f ur l age functnal gups The deepest gup the small tatrs) appear t act as psitin sensrs ather than as trque enerats The me supefi cial etensrs multiidus and ilcstalis lumbm and lngissimus thracs fall i thee categries t  generate arge etensin mments ver the entire luma regin 2. generate psterir shear r 3. affect and cntrl ny ne r tw luma segments The rles f the admina musces in tunk ein an in tunk stabilztin wee highlighted tgether with the rles f the psas and quadatus lumbrum earl many muscles play a lage rle n ptectng the lw ack f rm inury hapter 3 apples these findings t eercise regimens fr individuals with lw ack pain

Ligaments hen the umar spne s neither fleed nr etended   nly muscle cntr iutin s need e cnsider ed n t he mechanics t s uppt the spne  weve as the spine flees ends and twsts passive tssues a stresse the resultant fces f thse tissues change the intepretatin f nj eacerbtin and/r the discussin f clinica issues r this reasn, I intduce the mehancs f passive tssues in this sectin flwed y sme eamples llustatng ther effects n clincal mechancs ls fascinatng is the distriutin f mechanreceptrs dcumented in eve lumar liament and fascia. Smn and clleagues' 2 000) recent evidence suggests a gnfcant prp iceptive rle fr spna ligaments

Longitudinal Ligaments he verteb ae ar e i ned t f m the s pna  clum n y tw  ribnl ike l aments t he anteri lngitudnal and the psteri lngitudinal ligaments, which assist n restrcting ecessive ein and etensin see fgure 434 th liaments hve bny attachments t the verteal dies and clagenus attachments t the nnulus. Very lttle evidence eists fr the pesence f mechanreceptrs in these liaments Psterir t the spinal crd is the lgamentum a whch s characterzed by a cmpsitin f apprimately 80 elastin an 20 clagen, sinifying a very specal functin f ths ligament It has een ppse that this hghy elasti structure, whch is under pretensin thrughut al levels f fein acts as a barrier t  material that cud uckle an d encrach n the crd i n sme regins f the range f mtin

7

w Bk D 

amm avm

Spasp os am 

spos amt (osal (m (val

o loal am Fgue 434

Poso loal am

Maor ma igamns No  conrovsy sroundng  inspinous igamn in igs 5 and

4.36. Adapted, by permiss on, fom  Watkins 1 999 Structure ad Fuctio ofthe Muscuoskeetal System. (ampaign, L Hman inetcs , 49.

Interspinous and Superspinous Ligaments T intrspinus and suprspinus lgamnts ar ftn assd as a sing strutur in anatmy txts atug funtnaly ty appar t av quit diffrnt rls. h ntrspinus ligamnts nnt adjant pstrir spins but ar nt rintd parlll t th mprssiv axis f t spn Ratr ty av a arg angl f blquity  as n a pnt f ntntin. r yars mst anaty ks v sn ts ligamnts wit an iqu angl tat wuld aus pstrir sr f t suprir vrtbra s figur 3 Tis rrr is blvd t av rgnatd arund th turn f t ntY wit t yptsis ing tat an artist ld t vrtral stin upsid dwn n drawng tr artists spy pid t prvus art ratr tan lk t a spn. Ts as rrtd by Hylings s figur 36) ntng tt ndd ths lgamnts av t bliquity t rsist pstrr sar f t suprr vrtbrabut als mps antrir sar frs during ful fxin Hylings 97. Wi many anatmy txtbks suggst tat tis ligamnt srvs t prtt aginst xssiv flxin

unctona l natomy of the umb ar Spne

77

Incorrect fiber orientation

Fige 4 35 For most of the past  00 yeas man y aatomical artsts have draw  the terspinous gamen t upsde dow  as so wn  n tis example Suc drawngs have cause d te  gamet functio to be misi terpet ed as tat o a su pporter of antei or shea r wich is icoe ctTe srcal igure o ths exampe  om J Watkis  999, Structure and Fu ction of the Musculoskeletal System, Campa gn  : Huma n Knetcs was dawn corre cty but it as bee atered to il ustate te ncorect edeing may atsts have drawn  te past Adapted, by perm ission from  Watkins, 1 999 Sruure ad Fuo fhe Mususkeea System(Champain, L Human Kinetics ) 1 49

Fige 4 36 e iterspnous lgament uns obiquey to the compessive axis ad tus has lmted capacty to chec lexion otatio o te s upero  vetebrae. Rather  te ntespious lgamet may act as a colatea igament cotroll ng vertebal rotaton ad m posng antero shear forces on the su peior vertebae (ZG) Zagapopysea joit or acet ot (2), (L3) lu mbar spnous pocesses. Adapted by permission, from  Heylings  1 978"Supra spinous and inte rspinous gaments of te uman lumba spne oura ofAaomy 1 25(  : 1 29 opyri gt Bakw e Publsing

sed n errneus nty), I d nt eliee this ntin is ect eylins (19 suestd tht the lient cts ike  clterl lient siil t thse in the knee hereby the ient ntrls the veterl rttin s it lls n rc thuhut the exin nge his in tun hels the cet jints rein in ntct, lidin ith ttin. Futhere, ith its lique line  ctin, the interspinus ient rtects inst psteri shering  the superir ete e nd is ii cted in n inj ury sceni discussed ter in this chte. n cntrst t the interspinus ient, the suesinus ient is lined re r less rlle t the pessie is  the spine, cnnectin the tips  the steir sines. It ppers t ride resistnce inst excessie rd lexin. Finly bth suspins nd interspinus ients he n extensive net k  ree nerve endins tye IV recets) hi, en, nd ird, 19 tethe ith uini crusles nd cinin crpuscles hi et , 988 Jin et , 199. th hi nd lleues 1988 nd Sln  nd cleues 000) suest  prrice tie rle r the ligents t peent excessie stin in uly exed pstures nd in their rchitectequite pssiy hen unde excessie she d.

8

ow Back Dsoes

Itesp os  iga met Achitectue The terspous lige ppers o provide  coller ctio s t uides the slidig otio o he ce joits d checks posteor she o he supeo vetebr he ip side o this uciol roe s th duri ll lexio the superior vertebr s shered erioly, oe ddig to the eto she oes prduced i  orrd bed postre Therpeutic execse recoedig ul spie exio strehes us osder he result sherg orces iposed o the joit by iterspous lge stri Too oe eve those ptiets ih she pthology or exple those ith spodyloshesisre prescibed exio stetches hs ppes o e lldvised

Other igaments in the Thoraco-umbar Spine Oher igets i the thorcour spie ilude the ertrsvese ies d the ce psue •  g These ligets sp he trsverse posses d hve bee rued o be shees o coecive issue rher th true lies (Boduk d Toey, 991  ct Bogduk d oey sues tht the etrsverse ie ee ors  sept betee the terior d poserr usulure tht s  ebyoloicl holdover  the developet o hese o setos o uscle •  p The e cpsule cossts o coective tssue ih ds tht resrit oth the joit lexio d the dstrcto o the e sures tht esult  xi tis The lies tht or he cpsule hve bee docueted o be ri  proproeptive orsPcii d Ruii corpuses vugh et  996 Li d Pic kr  99)d hve bee obseved o respod to ulti dreiol sress i et , 995) t lest i cts

Normal igament Mechanics and njury Mechanics Det the roles o ligets hs ivoved qulittve iterpretto usi their thets d les o ctio togeher th uctol tess  hih sucessive liets ere ct d the j oit otio essesse d Ely sudies ttepti  o detr ie the out o retve otriutio o ech liget to restrictig lexio ere peroed o cdverc preprtos th ere ot preoditoed prio to testi his usuly etils  lodi regie so tht the cdveric species better rele i vivo behvior Speiilly hey dd o ke io cout the  ht, upo det, diss be hydrophilic icrese hei er coet d cosequetly ther heih he sole discs i dveic species produced  tiicil preod o the iets closest to the disc  ippropritely suge sig tht the cpsur d litudil les re ore iport i esisi exio th they ully re  vivo For this reso these erly dt descri he ctiol rles o vrious lts ee ioect Theexio ork o  collegues 1995 Those shoed th studies the jor lies  resst eShr the suprspious liges erly soi the psterio loitudil liget d the cpsul ligets re iport r resisti lexio did ot epoy the eessry precodiiog discussed bove echi ilure o he ie ts is orth osdei Ki   993 oed h sot ssue jures re oo durig hiheergy, trut evets such s utoobile olisios Our o oservtos o pig d hu speies loded t slo od rtes i bedi d sher odes suest th excessive tesio i the loitudil

unctonal Anatomy o th umar Spn

79

limets cses vulsi r y filure er the ligmet ttchet site. Nyes d cllegues (994) ted tht sl str rtes 0.66%s prduced me igmet vulsi uries, hile fst stri tes (66%s resulted i mre midlimetus ilure t lest  mey ee limets. The ciicl results by sse (960) hever shed tht pprximtely 20% f rdmy selected cveic ses ssessed vsibly rutured lum itersus ligmets hile the sl d vetr ptis  the terspius limets d the supspius liets re itct. hese culd be csideed t represet the lvig ppulti. Give the bl ique er direct f the itersius cmplex see f iure .36  ge )  very iely sceri  iterspius limet dme is fllig d ldig  es behid drvig the pelvis rd  mpct d cretig  sterir sherig  the lumbr jts he the spie is fully xed. The itersus ligt is  mj ldberi tissue i this exme f hiheergy ldig chrcterized by terir sher dislcemet cmied ith ull exi. Csderig th vilbl dt r beieve tht dmge t the lgmets  the spe pticulrly the itersius cmplex, is t iey ur lift r the rml ccutil ctivities. ther ligmet dmge sees t ccur primrily durig tumtic evets, s escribed e lier The susequet jit lxity is el  t cceerte hrtic ches (Kirdy Willis d urt, 992 Wht hs bee sid i referece t the ee jit, imet dmge rs the begiig  the ed," is s pplice t the si i terms  eig the iititr f the cscde f degeertve chge.

Tr sil limets pper t e the esult  blistic ldi ticu lrly sls d flls r trumtic sprtig ctivity th the spie t its ed re  mti. Thse th recetly develp spie symts d ccmpyg sie ist ility c te recut pri icidets i hch the igmets culd hve bee dged.  f the tumtic e vet ccurs t r  ut t he delyed sequel e devep lter dur  evet t hme s this cmese? Aruig these tyes  ques ts requires  slid uderstdig  ijuy mechisms.

Lum bodo rsal Fascia (LDF) While  uctil iterpretti f the lubdrsl fsci D) (ls clled th thrclubr sci y sme) is prvided lter  shrt tmcl descrt s gve here. First, the sci hs y ttchmets  the tis  the sius rcss excet the shrter  i my idviduls) d t the psterirsuerr ilic sies  Sme scil cects css the midlie, suggestig se frce trsmissi thus cletig the hp ud the dme ith the revusly descried bdil sci teriry The trsverse bdmiis d iter blqu usces ti their strir ttchmet t the sci, s des the ltssimus rsi ver the upper rei s  the sc. The sc i rpi rud the c rms  crt met rud the lumbr extesrs (multidus d ps lumru grus f ilicst lis d gssius) d hs ee imlicted i cmprtmet sydrme (C et , 95; Styf, 97) see figure 4.37. ecet studes ttribute vrius mechcl rles t the ludrsl fsci DF.  ct, sme hve recmmeded liftg techiques sed  these hypt heses. ever, re they csistet ith exerim tl videce? Grcvetsy d cllegues (98 rly suggested tht lterl rces eerted by the iterl bique d trsverse bdmis muscles re trsitted t the D

80

ow ack Dsor ers

vi thei tthmnts t the t b, nd tht the s uld suppt substnti exns mments. They hypthsizd tht tis  tensin n the LD insed ngitudn tn sn by vitue  the gen fib bquity in the LD using th psti spinus psss t mve tgthe, sting n umb xtnsn Ths pps squen  vnts md n tttive ppsitin bus the L hs th gst mmnt m  l th xtens tissus s  esut ny xtens s ithin th D

oage ibe arangee i he LDF bnd  the l ba exeo r u ce and tedo ro  he hoacc cle togeher a they coe o the acral atache.  hu one o the unctio o the LDF appea o be actg a a exeo uce eac u -and a ara abdoinaback belt

Figure 4 37

Figue 4 38

tre  l e in the  bodoa a cia nd icate ha the ai doi i he do nant o ce activaor- a ea  h exapl e

wud impse th smst mpssiv pnty t vteb mpnnts f th spn. ev, thee studies,  pubishd but th sm tim, etivy leng th vibity  ths hypthi T sh n  gues 9 h pefmed mehni tsts n dv mt i; Mintsh nd gus 9 h  gnizd th ntmi innsistnis ith th bdmin tivtin n MGi nd mn 9 wh testd the vbity  D nvv ment ith the ltissims ds s  s ith th dmin s se iu 43 Ths tiv wks sh tht the D s nt  signiint tiv xtens  th spin nthess th D is  stng tissue ith  we vpd tti  lgn ibes suggestn tht ts untn my e tht  xtns 94, mus Bgduk ndnMintsh  inuum ntus bk bt In ditin th fsi ds ntin bt Ruini nd inin puses tge th it di s innevtin  hi t  . , 99 . Th tndn s  ngissimus this nd ilistis umum pss unde the LD t thi s nd ii tthmnts It pps tht th  my pide  fm  tinu stpping f th  bk msutu in y, th bdm in    n t ltissimus si s d tensin t th si nd stiness t th spin t pvnt spii typs  unstb bhvi nd tissu dmg (x plined in hpt 6 n spin stbiity

Lum bodorsal Fascia Anatomy N vin ustii s spei lit ing tehnqus t nv v th LD  xtns in  the spine. wev tvtin  th ltssimus ds nd th dp bdmin iqus ntuts stinng nd stbilizing s t th umb spin v th s guiins  tvting ths musles e pvid in pt  u theme, th D ppes t t s  tinuum nd pbby us  ppi eptiv untin. It is pt f  hp" und th bmn, hi nsists  th LD pstely th bdminl fsi nty , nd th tiv bdm in musls ltey th the tgeth mpte th stbiizing st (se fgue 4

uncon nomy o h umbr Spn

81

Abdomal asca

mbodosal asca Fgue 3 e abdom ina  asia aneoy, a nd te  DF, posteioy  ae passive pas o e abdomina oop. e laea ave musu laue (a sves e abdomi s and ienal oblqe seves to eso e oop (das ed aows).

Clinically Relevant Aspects of Pain and Anatomi c Struct ure Recall rm the inrduction of this bk that tissue amage can altr th bimchan ics f a spina joint an that once he biomechanics have change any innrvate tissu can be he canidate for sympoms. Pain srcinates with the fr ne nings f te varius pain eptrs that tyically fom small ne ibers As nt in Guyn (98, nt a f the sma fiers oriinate in pain recepors: som iginae in ans sensitive t temperature prssure, o thr "uching sensains Pain ay als be initiate at hiher eves in the pain pathway Howe and ceagues 977 emn stra that mechanical pessues on the orsa ro ganglin prouce ischars fr up t 25 minutes foowing the remva of the mechanica pessure In aiin Cavanauh 995 shwe that nee endings are sensitive t chemica meiats reeasd uring tissu amae an infammaion Sme stuies have attempt  examine inammatoY pocesses by th injction of various chmicas F example, Ozatay a n coleagues 994 in ete crrageenan in to th reion of nrv e rec ptrs arun the fact joints f rabbits an eporte hat the ischarge rm th prssure sensitive nuons laste fr thre hours This fining sugess that tissue aag

8

ow Ba Dsor ders

poduc foy pocsss  cobu o  og- sc sps   c uy Cuh (99 psd dc o docu h possb o of ous chc do h  ou copo o h p phwy o h p  poducd du  h  omy ooo. Much s o  udsood Bogduk 983) podd  xc w of h o of u ss. o p, h f c s w v d wh   o f ow d hghh sho d s susg boh p d occp fucos  v dgs h s b obd oud h supc s of v dscs

Tissue-Specific Types of Pain  h hd o po pc wh dc chc o f spcfc ow bck su d h u p. ddy h sus  d g h sg sbjc (ys) d h subjc u of h oseos b I b hy  woh pog ohss  obd hs sghs fo dwg EM x ps  whch d w usd o p f w EM cds  h psos, qudus uo ufdu, d h  of h do w My pop h  pcd h bu o  h d p s h sk  Ths s cuou p, s h ppco of oh c d  ho  f sm  h d pps pssu o d pucu hogh h bodos fsc h p s f s  scp sso  d sos s  cc cu h sm s  of p s f  h d posss houh h dff hhs bwe h  of usc of h do w  s sg o o h fbgc ps so s p hs scch yp of uscuy cd p s y ss wh pu/fsc o Oc h d ws d h uc o p ws pcd, ju  ccso f of chc pssu  h d ouchd h pou of h do c  y oco  g y sck fg ws poducd  h bd  focusd oy o  s  jus ow h . s h d ochd h bo of h eb  wh Y gh pessu  y pd d b p ws poducd s o h p p cd o  kckd  h shs. Oc g h d u  h hs  h xpcs of   pso Noh, h d pd cd u sgh o h p of p poducd  spcfc sus.

Can Pain Descriptors Provide a Reliable Diagnosis ?  s y poducd f ssu o pcu chc od m h ud h so s u  y o y o b  cdd s fo oucs  f p bsd  h pc o bc of occp  dgs h y   dsoY gu f h ood s suffc s o dg su d podu bchc chg  h j h h dg ps of oh sus  dubd hs  hugh o ssu y o b cpb of pdc p f  s dgd scy  sf od o oh sub d ss p  esu. o mp  d uus d dsc d ps   ouc of p s  coc f d p fcu o u ho Bu dp fcu c cs sgfc dsc hgh o whch c d o  p copx jo by, d ubs u fc ood, d o o Oc h bomchcs of h jo h   d,  s  o og ffu o p o d go s spcf c ssu dmg;  h pc s cmp. uc dss s h o fb op

unconal naomy of he umbar Spne

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A Final Note n this chapt a rudimntary anatomicalomhancal knowld i aumd n th art f h radr Ung thi fo unda ion om anatomica faturs w r rvw that ar not oftn conidd or dcud n a anatomical txt. iou disussin of anatmy must involv funtion and, y xtnion mut nsidr biomhanis an motor control. opfully  th funtion al dicuion thughout th hat hav stimu at you o v mor conidration to h archtctur of th lumbar pin Th halln for th scints and cincian alik i to com convsan with th fun tiona imliation of th anaomy which will guid dcions to dvop th mo apropriat prvntion prgram  for th u nin ud and th bst tratmnt f r patints

References Adams M , and Dolan, P  199 ) nt adancs n lumbar spinal mchans and thir ln al significan Clinical Biomechanics, 10 : . Adams M A a nd Hutton W.  98 Gradual dsc rolap s. Spine 10: 24 Adams, M.A. and uton W. 982 Prolapsd inrbral dsc: A hypxon iu i 7: 14 Adams, ., and Mui H 196 Qualitai chans th ag o potolyans of human lumbar diss Anals ofth  Rheuatic Diseases : 289 Amono-Kuofi, H. 98 Th dnsity o muscl sinds in th mdia, intrmdiat and latral olumns o human intnsic ost rtral muscls. joural ofA ato 16: 09-19 Andrsson A Oddsson,   Grundstrom O.M. lsson ., and Thorstnsson A 996 MG atiitis o th quadatus umorum and rcor spna muscls durng flxion-rlaxaton and othr motr tasks inical Biomchanics 11 92-400. Andrssn . Oddsson L, Grundsrm . and Thrstnsson A. 99) Th rol of h soas and Scandinavian iliaus musls for stability and momnt of th umbar spin lis and hi oual ofMdicin ad Science in So, : 1016 dznski   992  Applicaton of s ckl photoraphy mthods to th instiation s of dfrma erimental mchanic.  York: lsr ion of h rbral ach In: ittl .G d) ogduk,   190 A rappraisal of h anaomy o th human u mbar r tr sina oual  Anato 11 : 2 gduk   98 Th nnaton of th l umba sin Spi, 8: 286 ogduk  and nl  984 Th mnisi of h umbar zyapophysa ints: A r o thir anatomy and clinal sinificanc. Spine 9: 44 i 9: ogduk  and Macintosh  1984 Th ad anatmy o th thoralumbar fasa 164 ogduk , and o my   991  Clnial anat omy of th lumba spin  2nd     ork: Churhill ingsn  nkmann P igmann, M, and Hil,  1988) aigu fractu of human lumbar rtbra. iical iomchanics  Supp 1 : S2 nkmann P. igmann M  and Hilg,  .  1989 ditio n of th mr ssi strngth of human lumbar rtbra. linical ioechanics 4 up 2) Car D Gibrson , rymy r,  , Kra, M an d o M  1 98) umba paaspina l omart mnt

syndom: A cas port ih physloi and anatomic studis Spine 10 816. Callagan P and MGill S.M. 2001) Intrtral disc hrnation: tudis on a orcin ml sd t hhly rtiti flin/xsion moton ih comssi foc inical iohanics 16  : 28-7 Caanaugh  M  199  ual mchansms of lumar pain Spine 20 16): 1804 Caanaugh M, Oaktay A., amashita T, and Hin A 996) Lumar at pain: iomhan is nuoanatomy and nurophysioloy jo al ofBio chanics 29: 1117-1129

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ow ac Dorder

Cholewicki, , l, K, and Mcill, .M 999 The inaadoinal pee echani fo ailizin he la pine jor al ofBoea s 3 0): 13-17 Cewell A.   Oddon   , a nd Tho enon, A . 99 he infle nce of dd en pe baion on unk cle acivi in inaadoinal peue whie andin. ereal Bra Resear 98: 33-31 Cipon, P, Beleen, .  Viaino ,  .  Beea n, P, ole,  P, and Paad  P 995 Repon e of he la pine de o hea loadin n: I reeo rog boeasp 11 Deoi: Wane ae Univeiy Dicke, JP Pienowki, MR. and Bedna, DA 99 Deoaion of veebae in vivoIplica ion fo face join oad and pino poce pin inuenaion fo eain eqenial pinal kineaic Peened a he Canadian Ohopaedic Reeach ocie, Qeec Ci Ma 5 Fafan HF 973 Meaal sore ofe low bak Philadelphia: ea and Febie Fhie, D.P. and chaffle M.B. 99 Faile echani in han veeal cancello bone Boe 15 : 105 -109 . alloi J , and apoi, T.  9 5 Achiece ini ee de ve e d poin de ve ai qe e phioloiqe. Re r Pai, 3: 88 oel  K , Monoe, B.T , ileon,  . and Binckann, P. 995 Inelaina h ea ee and anaeepaaion in a dic: Finie eleen anai of he 34 oion een jeced o axial copeive load Se 0 : 89 oel VK Wilde, D., Pope, MH., and Edwad WT. 995 Conove: Bioechanical ein of he pine: oad conolled ve diplaceen conolled anali Se 0 354-357 Se 1 50 odon .J, e al 991 Mechani of dic peA peliina epot acovek, , Fafan F, and a, C 981  Mechani of he la pine Se  : 9 nnin, J, Callahan, P, and Mcill M 001 The ole of pio loadin hioy and pinal poe on he copeive oleance and tpe of faile in he pine in a poine aa odel Clal Boeas 1 : 7-480 on, A C 98 1  eno  ecepo and hei ac echan  of acio n. In: Texbook ofeal ysolo6h ed p 588 Philadephia WB ande Hadcale, P Annea P, and Foe, D 99 pinal anoaliie in on fa bole joral ofBoe a jO Srge, 74B  41 Henke, K., haa, MT, Peeow D. and Depe JA. 1988 Relaion of endexpiao ln vole din execie. joral ofle Pysolo  135-1 Helin D A   978 papino  and inepino lia en of he han ba pine. joral ofA aoy 13: 17 Hode, PW and Richad on, C .A  1 99 Ineff icien cla abili aion of he lba pine aociaed wih lo ack pain: A oo conol evalaon of anve abdoini Se 1 0-50 owe .F. oee, JD, and Cavin WH 977 Mechanoeniivi of doal o ania and chonicall inoed axon: A phioloical ai fo he adicla pan of nee oo copeion Pa 3 5 Jan, H, Rel , Rao, , Moea, MJ, Hl, D, and Banall, K.M. 995 The nae and diiion of he innevaion of han papinal and inepinal liaen Se 0: 89-87 Jke D. Mcil, M and Kopf P. 998 Qaniaive inacla oelecic acivi of la poion of poa and he abdoinal wall din cclin joal ofled Boa 4 4 8-38 ke D Mcill, M, Kopf, P, and efen . 998 Qanaive inacla oelecic acivi o la poion of poa and he adoinal wal din a wide vaiet of ak Mee a See  Sos a erse 30 : 301-310 Kele T., Ziv, I, Moelano, E, and penle D.M 993 Inedependence of lma dic and bdcal one popeie: A epo of he noal and deeneaed pine. joural Q( Sa Dsore  : 10-113 Kin A I. 993 Iny o he hoa cola pin e an d pelv i  n: Nah and Melvin Ed.  Aeal  boea s a ree o  ew Yok: pine Kikald-Willi WH  and Bton, cv 99 Maagg lo baka 3d ed  ew Yok: Chchill ivinone ehan, , and Mcill, M 001 Qanificaion of he diffeence in EM anide eween ppe and lowe ec adoni din eleced nk execie Pal era8 1091101

nctonal natomy o t he mb ar Spne

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z ., and Chn, .R. (000) nrrral dsc cll dah s dndn n h magnd and dran f snal ladn Sp 5 ( ) 1477 -148 3 , w.w, uk, KK, Chun KMC, Fang, , lms, A, and Lng, C (001 Enrgy absrn f human rbral dy undr fag ladn n: Asracs, nrnanal Scy fr Sudy f h umar Sn, Ednrgh, Scland, n 193 Lcas, ., and rsl r . ( 96 ) Sa f h lgamn s sn. T ch. Rrt N. 40 , mchan cs ara, nrsy f Calfrna, San rancsc. Macnsh, .E, and gdk, N (1987) h mrhly f h lumar rctr sna Sp  (7 658 Macnsh E, gdk, N, and Gracsky, S (1987) Th mchancs f h hraclmar fasca Clal oma : 78 Marklf, KL , and Mrrs, M  ( 1974) Th srcu ral cmnn s f h nrrt ral dsc joal 0/ o ad jo S 56A (4) 675. Maas, WS , and Granaa K. ( 997) Changs n runk dynamcs and sn ladng durng ra d xns Sp : 564-570 Maras, WS., Jrgnsn M. Granaa, K.P. and Wand,  (001) Fmal and mal runk gmry: Sz and rdcn f h sn ladn runk muscls drd frm MR Clal oma 16: 38-46. McGll, SM. (199a Elcrmyrahc acy f h admnal and l ack msculaur durng h gnran f smrc and dynamc axal runk q: mlcans fr lmbar mchancs. joal 0/ opad Ra9 9 McGl SM . ( 1991 ) Th knc nal  f h lumar rnk msculaur au hr  rhgnal rhadc axs n xrm surs Sp 6 (7) 80985 McGll S.M (99) A mylcrcally asd dynamc 3 mdl  rdc lads n lmbar sn sss drng aral ndn. joal 0/om a 5 (4) 395 McG l .M ( 996) A rsd anamcal mdl f h admnal m scula ur fr s fxn ffrts joal o/oma  9 (7: 973-977 McGll S M (997 nd ar: mchancs  f l ack njury mlcans n crr n racc and h clnc. jo al 0/oma  30 (5): 46-47. McGll .M kr, , and Axlr, C 996) Crcng runk mscl m band frm MR and C scans f sn srs fr s n sandng srs. jo al 0/om a  9 (: 643646 McGll SM, Jkr, , and Krf,  (1996a Arraly lacd surfac EMG lcrds rflc d muscl acy (sas, qadras lumrm abdmnal all) n h lmbar sn joal o/oma 9 (1): 1503507. McGl  M , Jk',  ., and Krf, P. ( 1996 Quana nramscuar my crc acy f Clal oma 11 (3: 1707 uadraus lumbrum durn a d ary f asks McGl SM Hghsn RL and arks, K (000 Changs n lmar rdss mdfy h rl f h xns muscls Clal oma 1 5 (1): 777-780. McGll, .M, and Nrman, RW (1987 Effcs f an anamcally dald rc sna mdl n L4/L dsc cmrssn and shar joal 0/oma  0 (6): 591 McGll SM, and Nrman, RW (1988) Th nal f lumdrsal fasca frcs  gnra ack xnsn mmns drn sqa lfs joal o/omdal E 0: 31 McGll S M  a, N , and Nrman RW 988) Mas urmn f  h runk msculaur   ac  mas sng C scan radrahy: ulcans fr frc and mmn gnrang caacy ab h L4/L jn jo al o/oma   (4): 39. McGl l, SM, Sanaguda L and S ns,  ( 1 993) Masur mn f h runk musculaur fr m 6  L5 usng  scans f 5 yng mals crcd fr mscl f rnan. al oma 8: 171 Mcan RF, and cka, G (998) Mchanrcr ndns n hman hracc and lumba fac jns. p 3: 168-173 Nachmsn, A.. ( 960 Lmar n rdscal rs sr. Ata opada Sadaa (S\ 43). Nachmsn A ( 1966 Th ad  n lma dscs n d rn sns f h  dy.   R4 107. Nz, A, and ck,  (1986) Cmarsn f muscl sndl cncnrans n arg and small hman axal muscls acn n aralll cmnans.  ma So 5: 73-77. Nrman RW, W lls, R, N umann,  an k,  ., Shannn,  , and Kr r M 998 A cmasn f ak s cumla hysca rk xsur facrs f h rrng f l back an n h am ndusry. Clal oma  13: 61-573.

86

ow Back Dso rders

oys .R. D Luas .. a Tik PJ 994 Biomhais o gamt faiu: A aalyss of stai-at sstiy a mhaisms of aiu i pmats. jrnal fBne and JOn rge 56A 26. Ozaktay A.C t al. 994 fts of aaga iu ifammatio  abbit lmba fat jot apsu a ajat tssu. jrnal fNe rcence Reearch 20: 55. Potil .A.  a  DRosa  C .  1 998 Mechancal l back an: Peece nnctnal ana Philalpha: WB aus Rihaso c ull G  ogs P a His ].  1 999 Thaput  s fo spal sg a staiatio i low ak pa. iugh otla: Chuhill Ligsto. Rssa P.M. 960 Th sugial aatomy a pathology of th spaspous ad tspius Aca hadc lgamts of th luma sp with spal f to ligamt uptus. candnaca ppl. 46 jrnal fBne a ndjn  urge 42B: Roa R 1960 A stuy of th mhais of spia ijuis. 810 Robts   Mag ].  a  Ua ]. P.G  1 989 Biohmi a a stu tual pop tis o th at lag -plat a its latioshp to th tta ds ne 14 166. atagua P a MGill M 995 Th psoas majo musl: A th imsoa haial mllg stuy with spt to th spi as o MR1 masumt. jrnal Bmechanc 28: 945 hama M  Lagama  A.  a Roigu  ] 995 Rol o ligam ts a fats  lba sp stability ne 20 8: 887 ila MJ a Gbso 1.] 1997 Molig th mhaia bhaou f tal tabula b: fts of aglat hags i mostutu Bne 21: 9199. ia A. a ost .  1985  Th fi typ ompositio of thoa a luma paa tbal msls i ma jrnal fA na 141  oomow M Zhou B Has M. Lu Y a Baatta R. 2000 Th gamt-sula stab iig systm of th spi ne 2: 25522562 tyf ]  1 987 P ssu  th to  spia musl g x is ne 12: 675. Tsh  M  D u ].  a as  H. 987 Th aom ial musls a  tal stablity n 1 2 5 50 VaGaia J. Gi  G . a MGl   .M  2000 Abomia spo  dug u-ups o  both stal a lail sufas. Phcal era80 6: 564569 Vma T. umi M ad oup ].D G 990 umba spal patho gy  aa  matia  lato to hst of ak pa oupatio a physal oadg ne 15 8 72 Wl D.G. Pop MH a ymoy ]W 988 Th iomhais of lumba s hat a th fft  ola a stality. jrnal fnal rde 1  16. Yaha H  wma   a Ria  C.H   1 988 uo hstology o th  lumba  s Aca rthaedc candnaca 59: 508-512 Ygg R. Calagha ]P. a MGil M 1999 Th po ial spi as a asoabl ml f th hma luma spi A aatomal gomtal ad fctial opaso . jur nal nal rder 12 5 41 542. Ygg .R. ad MG .M. 1999a Mhaial poptis a falu hais of th spi u posto sha loa Osatios fom a po mol jal fna srd 1 2 6 : 501-5 08 Ygg R  a MGll  M 999 Ato sha  of spial motio sgmts: mats kt s a sultg js os  a poi mol. ne 24  18: 1 882889.

Normal and Injury Mechanics of the Lumbar Spine

C

ater 4 escbe te tsses or e anatocal ars, an ter rle n ncton ts cater wll escre te noa ecancs of te l lbar sne Snce os becancs texts oe escrtons of sne n,  ll aress t n brefl ere nstea,  wl focs on e nctona lcaons of ta ton, c are far e otant I wl also exlan n ecanss an te canes tat folw nj Controers reans as to weter ese canes ae a conse qence of nj r or n fact la a casae ole on coleton o ts caer o wll be ale to exlan te e f tsses n aos tass an conseqentl ent bacsan tecnqes n atn  ll nestan e canes tat folow nj  wc ae an act on fncna abt an reabltaton ecsons

Uy

Kinematic Properties of the Thoraco-Lumbar Spine Te anes o oacc an mar semental moton abot te tee rncal axes (son n able 5.) emonstate te reate exon extenson, an ateral benn caablt o te l ma eon an te relat el reate r tstn caabl t o te toracc reon le te semental anes sown n e able are olaton aeraes ee n mn a a are aat exsts an eole amon ae  s (McG l, nln  an Peac,  999, an amon se ents tn an nal Jont stffn ess ales cone te amon o f translatonal a n rtaonal eaon of a sne secon ne te acaton o force o oent Te aerae stfness ales (son n tale 5.2 coe  AstonMler an Scltz, 19 ocent te ranslatonal stfness of te sne n a netra ose te ncate reater stff ness ner c resson tan n er sear loas  In rotaonal oes eate sfn ess occrs rn axal orson tan rn rotaton aot te lexon/extensn an laeral benn axes le eneall te rane of oton ecreases  ae cetan nres, arclarl to te sc can ncease te an e o oton n benn an sea

87

88

Low Bac Di sodes

Tabe 1

Leve

Range of Motion of Each Spine Leve (in Degrees)

Fexion

Fexion and exension ombined

xension

Laea bending

Axia wis

T-







T-





8

T-







T-







T







T





8

T-







T-







T-







T-







T-







T- 

8

 

8 

 

-









-





8



-









-









A daa are om We and Panabi (19 78) excep fexon and exenson lumba daa wch ae om Pearcy e al (98) and Peacy and Tibewa (198)

tasla to  S  Ml , a Sltz 19  Kal ls a  t 9  l at ts la stabl ots  fat jot at t ata a qat th cas  t a o oto abot al t s axs as s at cs fo a  t as  a IV. aal tas f t als a ost alt  ts stas t ts xta oto s la b xt lss o ot  a V scs whch a aatz  collas a stt fa to Taaa t a, 2001)

Normal ad Ijury Mechaics o the Lumb ar Spie

Tabe

S2

verage Stiffne Value for the dult Huan Spine Comp

xal oon

Bending

hea n./Po.

La

ex!xt

Lat.



/



/









/



/





-



/



/





ne level T-T

9

Compesso and sea r vaues are gven in ewos pe mllimee and bendg and axia orson n newonmeers per radia. TT daa from We and Pajab (98) 1 daa om Scuz e al. (199) and Bekson Nacemson and Sulz (199)   S1 daa from McGasen e al. (1987)

L



As t spn os n t nsons (flxonxnson aral n n tws t  lnn of scl  ctos can  wt rspct to   tral ortopc xs Ts cass  ro of t aros s cs to can o t s r r at contrton to procn a spcfc ont cans alon wt  rsltant jont coprsson an sa. Msc lnts an  ont pontal as a ncton o spn post ar sown n ta 42 p 65) an tal 5. 3 A ran of  xtr pos s  sown n   5    o scl s clos o t spn oosly o no t n ro rt lnt xcrsons

Motion

or Normal

metry?

tffnss asyrs wn nn to t r copar o  lf an wn twstn clockws copar to contrclockws at spcfc rtral lls ar not ncoon Ts fnn s of rat poranc o  clncn wo y sos sspct patoloy t a spcfc ocaon t s sply xprncn noral anaocal asytry Rcnt wok y Ross an collas 999) xplfs  pr n assn tat  on wt n sytrc fl pon palpation s poloca Cncn wo o to a typc al oton palpa on p losopy wl oftn nt fy an ano n t  spcc spnal  as  art o rapy os t asy tc sffnss ay sply  asytc skltl anatoypraps a sn fc w a nq anlar orntaon Oosly sc a jon wol  st to ny "olzn trapy



Table 3

Momen oenal (N  m) of Some Represenaive Muses in Varous osures Shown in Figure 

use

Fore

Uprg sanding

(N)

b

B

T

350

-28

1

R tna l obliqu ()

35

-

R ntnal

280

2° R aeal bendn

° exon F

B

T

F

B

6

-35

1

2

28

2

27

9

-7

24

15

-

-15

19

6

-9

8

3

455

36

23

9

35

23

R pas umboum (4)

595

23

23

-

23

R iliocostalis

210

18

5

1

280

24

10

15

5

40

R multiidus

R psoas (L1)

R ctus

1

ws

Cmbned



B

T

4

-33

20

5

28

6



20

22

-14



8

2

2

33

9

3

24

5

38

23



23

8

23

22

8

23

25

6

8

15



8

15

2

8

15



0

24

3

3

24

12

5

24





4



5

12

6

6

3

4



4

0

8



-4

8

6

5

9

5

5

8



-6

3

5

1

2

5

1

3

5

1

2

5

1

2

3

5

9

2

1

9

4

1

6

3

-4

8

T

F

B

8

-29

5

28

1

-8

3

8

20

8

36

24

24

-4

23

8

4

2

3

22

0



5



9

5

-3

98

5

1

54



9

T

abdomnis

obiqu (1) R pas

umboum (L)

lumboum R ongissimus

hoacis R quadatus

umboum R atissimus dosi (L5)

4 continued

Norma ad Ijury Mechacs o the Lumbar Spie

Table 3

9



ly a poo o some msces ae repeseed; for example te amiae o psoas o  1 s sow raer a e woe psoas.  Combato o 60° fexo 25° g aeal bedg ad 0° cotercockwse twis i oe posre; fexo;  laeral bed; T axal tws

bF 



 

eprinted, by permssion, f om SM McG, 199 ,"Kinetic potenta o fth e umbar tunk muscuature about tree orthogona othopaedic axes in extreme postions, Spine 19(8): 809-815. ©Lippincott, Wiams,and Wikins

Fgure

5' A rage of exteme poses wee cose o assess mscle egt cages (tabe 4.2) ad e poe ia to podce ree dimesioa momets (abe 53) Posres depicted are (a) prig sadig  60° lexo 25° R aera bedg 10° twis ad combied.

()

()

()

Lumbo-Pelvc

hm

The of orso fleon sess ha he frs 60° rs n b aespcal paceescrpon n he l ar spne whe an fher fleon s f acclsh feon abo he hps see fre 52) Ahoh hs noon s e lar n

>60'

Uprgt sanng

Spna fexin

Spnal fexn an pelic iing

Figue

52 Te mbo-pevic ytm is te texbook descipo of ow peope bed over. Te rs 60° takes pace  e lmba spie (exg) wile fe roaio o e oso s accom plsed wt roao abo e p. We ave eve measred ts seece i ayoeom pofessioa aee to back paie.

()

92

Low Back Di sorders

ccal exoos, we have never mease hs sc seqece  aoe  ac Ompc wehles aemp o o he opposehe oc he mbar spe cose o he eal poso a oae almos erel abo he hps he he mba spe a hp  epla s qafe  os eople,   s apa  e ha orso lexo s accomplshe wh a combao of hp moo a mbar spe exo I fac ve he ame a a ls s esses ass ocae wh lma exo avoace o ll spe lexo s boh pohacc a herape c o mos paes he ee ha he lmbopelvc rhh (w h sc separao of spe a pelvc moo s eeca l, as escbe  so ma exboos appears o e a ccal mh a o he pro c of q a fe spe a pelvs moo

Kinetics and Nomal Lumba Spine Mechanics eeao o he co of he aaomcal copoes of he lar spe reqes

• aass o her archece a eal acvao of sces, a • owlee o foces  he val sses (b oh acve a passve r a we vae of ass

Ths formao s ccal fo esa how sse overoa a jres occr a aso fo opz  reame  s ae es o spec c spe j U able 54 a fre 5.3 pove acvao eves qafe wh srace a amscl ar MG o a vare of  orso m scles a ove a va e o acves These wl  be reere o hoho hs boo Ths seco wl aess seveal sses a coove rses ao  he coa  epe ao o he ho acomba a aom Gve  he  a l o he c ca a  sces o eas v a sse  oces  vvo, he o eae opo s o se sophsca e eas e ec hq es o coec varos boocal sas m v secs a erae hem wh sophscae oel appoaches o esmae sse oas  chaer 2  e scrbe el he echqe we se o assess he varos sses  hs chape ( he va spe

Standing and Bending Forward Sevea ses ove he eas have show he exo/reaxao pheomeo, o he appae moelecrc sece of he ow ac exeso mscles  a sao lexo aeve The hpohess has ee ha as fl exo occrs ehe he exesors sh ow her eral rve  refex or he passve sses sl ae he loa as he sa e  exo A s b McGl a Kpes 994) s he va spe appoach escrbe  chaper 2 qafe val sse orces, hs a moe sh o he ersa o hs as As oe es far he spe flexeshea he exesos ero coraco As lelev fexo s poache passve sses rapl aeeccec ove mome co, heap msces o hs ole a acco o her moelecrc slece Fe 54 shows he relave coo o he mscles a he passve sses (lames, sc, a ) o he eaco moe hroho he moveme, whe able 5 . 5 oces he sbo o sse forces a he momes a o oa coseqece ees , he "reaxao of he lmbar exeso sces appeae o occ ol  a eecrcal sese ecase he eeae sbsaal foce eascal  l spe exo hroh srech Pehaps he em fexion/reaxation s arae

Table 4 Subjec t Averages of EMG Activation N ormalized to Tha t Actvity Observed During a Maximal (1 %)-Mean Effort and (Standard Deviation in Parentheses) Psoas c han ns nal obl iqu  n nal obiq u, and ansv s abdomins a i namu scula  c ods whil cus abd omini s cus mois and co s pi na  a su ac  l cod s.

Psoas 

ask

2

24(7)

IOi

Ai

5(±5)

1(±9)

48(±8) 55(16)

14(7)

6(9)

5(2)

15(±2)

4(±3)

12(±9)

62(22)

8(±12)

6(±)

7(6)

32(2)

8(±5)

6(±8)

6(±4)

37(24)

23(±2)

7(±)

28(±9)

69(±8)

8(7)

6(±4)

44(±8)

74(±25)

42(29)

5(4)

24(±4)

2(±1)

57(±22)

(±9)

5(8)

21(±16)

5(±3)

58(±24)

2(24)

5(8)

7(±)

28(7)

43("12)

6(±4)

0(±7)

Pssh siup

28(23)

34(±8)

5(±4)

22(±14)

2(3)

7(8)

(14)

9(±4)

4(±)

24(5)

25(±8)

22(±7)

8(±9)

35(2)

33(8)

26(±9)

9(±8)

6(±16)

6(8)

68(±4)

3(±28)

56(±28)

58(6)

53(±2)

48(±23)

5(±3)

4(±4)

23(2)

5(±3)

5(5)

24(7)

Isom hand on (l  han d igh hand

 igh n

 l n)

Coss culup (igh shoud l should

 acoss,

 acos s )

Ss 4(3)

nn  siup

Saighlg ais

RFs 6(±)

5(±2)

nn  g as

RAs

Oi 44(±9)

Saighlg sup

nn culup

Isom si d suppo (l  sid down)

2 (±7)

12(±8)

43(±3)

36(29)

39(24)

22(±3)

1 (±1)

24(±5)

yn. sid  suppo (l sid down)

26(±8)

3(±5)

44(±16)

42(±24)

44(33)

4(±2)

9(±7)

29(±7)

Pushup om 

24(19)

2(5)

29(±12)

1(±4)

9(±9)

29(±)

(7)

3(±4)

Pushup om ns

4(±1)

(±7)

19(±)

7(±9)

8(±8)

9(±)

5(±3)

3(±4)

9(±)

3(4)

3(3)

6(±7)

6(±5)

4(2)

6(5)

37(±3)

16(±8)

5(±6)

5(±4)

(±1)

(±9)

17(±23)

6(±5)

62(±2)

i ligh load (2 g)

W

Psoas

i havy load (51 g)



Table 4 1 +

o

Task

soas 

soas

2{4

30 g (66b

2



I



(

{4

Rs

RFs

s

5(3

5(1

0(

3{3

3{4

(

3{6

9(5

6{4

6{±

0(8

3{3

40 g (88b

3(5

4{

 (±

0(6

8{6

6{2

0(8

3{3

 g

3{2

(2

O(l

2{1

2{2

2{

10(±9

2(

2(1

Satd isom twist CCW

30(20

1(5

8(±8

43(±25

49(±35

(22

7{4

4(±6)

Satd s om. twist CW

23(20

1(±8

52(3

5(

18(9

3(O

9(0

13(±8)

Standi ng h p i ntnal rota ton

2(18

0(±9)

18(12

24{23

33(±20

3(9

9{±7)

18(6

Standi ng hp trna rotaton

2(20

22(19

(13

2(9

31(±

3(8

19(1 

1(9

Sittng ip intrnal otaton

9(5

21(±18

36(31

30(30

3(29

8(8

20(9

2(8

Sitting p trnal rotato n

32(±25

25(±20

1 (±9)

5(1

6(13

5(9

6(3

8{±8)

2(

7(5

3{6

3{3

4{2

1(9

4{2

5(8

Symmtic buct hold, 20 g (44b

Sitting upight Sitting slouchd/rlad

4{4

3{3

2(5

2{2

4{±3)

(1

3{2

5(8

Qut standing

2(

1(1

3{4

5(±3)

4{±2

5(±5

3{3

1(1

{2

2(1

12(9

6{3

5(3

1 (5

4{3

{8

9(0

 (2

1(8

8(14

2(

3(

3{2

1(3

Standing latral bnd, r ght

6(5

 (±2

9(18

18(14

25(20

14(9

3{1

8{8

Satd atal bnd movng t

2{3

1 (1

21(±9

{

(1

13(8

4{±3)

6{

Satd latal bnd, movng rght

18(2

12(2

5(26

10(

12(

(20

5(4

5(8

14(9

8{4

6{4

5(3

5(±5)

9(23

5(3

6{8

Standing tndd Standing latral bnd, lt

Uprgt

eprinted, by permiion, rom DJuer, S.M. McGi, S.M Krop,TSteffen, 18,Quanttative intra muuar myoeectric activity o umbar portion o poa and the abdomina wa durng a wide varety o tak," Mdcn and cnc n ports and Excs 3013 ©Lippincott, Wiiam, and Wikin



O

Straigh-leg situps



Bentknee sups



Pressheel situps







L  

Bentknee culups

 

Bentknee leg ase



Sraightleg aise



 J:  �

Ismeric hantknee ( hn knee/ han knee)

Css (t / shule) curup

smerc sie suppr (le sie wn)

Dynamic sie supp (lef sie wn)

 �

Pushup frm eet

Que staning

Saning exene

,

Saning lateal ben let

Sning latel ben rght

"

See atel ben mving e

Seate aera ben mving ight

,

Seate upight

Seate smetrc tws (CW/CCW)

Sanng hip atn (intenal/extena)

Seate hip atn (ntenal/extena)

f t �

n

�

t I 

Siting uprght

Pushup m knees

Symetic bucke h (20/30/40/0 kg)

Fgure

53

\

Siting sluche, reaxe

Li igh a (20 kg) Li heavy la (501 00 kg)

 \

Semat doumetg vaous asks during wi EMG sgnas were obanedThey ae sted n able 54



Reprinted, by pemissionfrom DJukerSM McGi SM Kropf, Steffen18"Qantitative inramuscular myoeectric activiy of umbar potions of psoas and the abdomina wa durin g a wde varie ty of tasks Mdicin and Scinc  n Spo and Exci 302) 301 310. © LippincottWiiams and Wikins

95

96

Low Back Di sorders

200

150

E 

C  

 100

'                  \  \ / lj  V :, \,

50

 o

3

w mmet

I

 ,        9

6 Tme (s) Dscq

Liq



Msceq

12

GTq

Figue

54 During sanding to full forward fon h nsor uscls ccntrcaly conract ut transfr hir on supportng ro (MusclT) o h passiv ssus at fu fionh dsc (Disc) th uckd gu (GutT) and  igans (ig) No that so forc rans n t uscls wi passiv srcing

picy fo hoe who my be empi o mmze foce i he mue i ciic ei. Fhemoe he he od  bi ee chpe 4 fo  dicuo of he ime muce veco diecio d he o of he uppo i he eeo wih  feio d wod e cu o fo hoe wi h podyo hei o ohe moe b e he ibiie. Cey, ihe oe ouche or ee oche  eche wod cue i mi   coce.

Loads on the Low Back During Liing Du fi muce d ime oce euied o uppor he pore d fciie moveme impoe mm moh od o he pe. Thi  why if ech ie  o im po o  educe ow bc mome demd d he i of eceive o. The oowi empe demore h cocep. A m  ifi 27 k 5 b hed i he hd i   f ye. hi podce  eeo eco mome i he ow bc o 450 Nm 32  b. he orce i he vio e h uppo h mome mpoe  compeive od o he umbr pie of ove 000 N ( 1 568 b . Tbe 5 6 de i he coibo o h e o ee o mome d o he foce rom he mc compoe. Thee oce  hei efec e pediced ui he ophiiced mode ppoch which e iooi c obied diecy fom he bec eeochpe  hod oe here hi 7000 N (568 b o compeo bei ce 2). dme i be vey wek pie,  houh he oece of  he um b pie i   vere hehy yo m po y pproche 125 N 26883360 b Adm d Do 15 I eeme ce, compeve o o he pie of compe i ive weih ie hve fey eceed e 20 N (4480 b Choewici, Mc Gi , d Nom 1   )  edi he dividu muce foce, hei coibuo o ppoig he ow bck d hei compoe of compeio d he foce h e mpoed o he pie i vey uefu . I hi picu  empe, he ie voded f pie eo

able 

ndividua Muscle and Passive iss ue orces a nd Moments Duing ul exion

h mom nt was 1 Nm (38 Nm by muscl  13 Nm by li gam nts and 0 Nm by passiv tissu s such as th disc sin  and buc ld viscra) . h join t comprssion was 3145 N and shar was 06 N

Fre N

omet (Nm)

Cmpress

Flexi Laeral wist

N

Ser (N) Ateropserr Lera

Muscl R rcts abdominis

6





1

5

5

4

L rctus abdominis

6





-

15

5

4

0

1



1

8



3

L xtrn al ob liqu  

0







8



3

R xtrn al obliqu 



1



0

6



3

L xtrn a obliqu 







0

6



3

R int rnal obl iqu 

35

0

3





9

0

L intrnal obliqu



35

0

3





9

0

R int rnal obl iqu 

9





3

8

17



L intrnal obliqu

9





3

8

1



R par s lu mborum (L )

1





0

1

6



L pars lu mborum (L1)







0

1

6



R pars lu mborum (L)







0

6

8



L pars lu mborum (L)





-1

0

6

8



R pars lu mborum (L3)

3





0

9

4

6

L pars lu mborum (L3)

3

1



0

9

4

6

R pars lu mborum (L4)

3

1



0

30



6

L pars lumborm

3





0

30

-7

6

R ilioc ostais lu mborum

58

5

4



5

4

-

L iliocos talis l um borum

58

5

4



57

4



R longissimus thoracis

93



4

0

9

3

6

L longissimus thoa cis

93



4

0

91

3

6

R xtrnal obliq u 





(L4)

 97

o

Table 

Foe N Muscl

Moet N)

Copessio

Flexio Latea wist

N

nnd

Se N) teoposteo Lte

R quadat us l um bo um

25

1

2

-0

25

-1

1

L quadatus lumboum

25

1

-2

0

25

-1

-1

R la tissimus dos i (L5)

15

1

1

-0

14

-1

-6

L latissimu s do si (L5)

15

1

-1

0

14

-

6

R multi idus 1

28

1

1

1

26

6

9

1

28

1

1

-1

26

6

-9

R mu ltiidus 2

28

1

1

0

28

6

0

L mutiidus 2

28

1

1

0

28

6

0

1

25

1

2

0

24

9

6

L psoa s (L 1 )

25

-1

-2

-0

24

9

-6

R psoas (L2)

25

-1

2

0

24

9

6

L psoas (L2)

25

-0

2

0

24

9

6

R psoas (L3)

25

-0

1

0

24

9

7

L psoas (L3)

25

-0

-1

-0

24

9

-7

R psoas ( L4)

25

-0

1

1

24

9

8

L psoas (L4)

25

-0

-1

-1

24

9

-8

0



L multiidus

R psoas (L

 Ant io longitud inal

0

0

0

0

Postio lo ngitudi nal

86

2

0

0

261

44

-

Ligamntum lavum

21

1

0

0

21

2



R inttansvs

14

0

0

0

13

3



L inttansvs

14

0

-0

-0

13

3



R aticul a

74

2

1

1

65

40



L aticul a

74

2

-1

-1

65

40

-

98

0

Normal ad Ijury Mechacs of the umbar Spe

99

o

Table 

Foe 

Moen )

Copession

Feon Laeal Twis



Sea ) Aneoposeio Laea

nnd R aricar 2

103

3

2

2

84

-3



 aricar 2

103

3

-2

-2

84

-3



ersos 1

301

0

0

273

42

-

ersios 2

345

4

0

0

233

268



ersios 3

98

10

0

0

1 94

238

-

rasios

592

41

0

0

59

79

-

R moorsa ascia

122

8



-0

09

-1



  moorsa ascia

122

8



0

09

1

-

18

Passive isc

-

9

0

0



-

-

G, ec.



11

0

0





-

b flxn t t , nzn lnt n oer pssv tss tnsn n rtn e ent eneton resonsbt te sltr An xe n w t sn s flxe s presente lte n ts pter. As escre n er 4  rs trs extensors re ver effetve lbr sne extensors, vn tr r nt rs. Aso, sn  ls er bo s lxe, lre ecton sr frs n e sne re ro (e r ce s n to ser ow on t vs Ts sr ores re sorte to  veY l eree b te ps lor extensr sles reror, te bon sles re tvte  poe  nele ontr ton to oentose sppor  r t tve Tese ses re tvae to stlze te snl oln, lo ts l bonl ctvt ses  ores son enlt  e sne A ore rost exnton  stzn ns s sbe n tr 6. Te ren xe eonsrtes ow fsl te os r srt n llstres w roer clnc nerreon eqres ntoll etle r bo rs t reresent rel (s c s ose nroe no te v s ne .  beleve t overslfe ree o s ve overlooe e nt e cncl orssve n esecll ser oonents of sar fore Ts s oose  ssessent of n enss n e forton of o rt exerse



00

o Back Dsorrs

Table 6 Musculature omonents or Moment eneration o 40 m During ea oading or a Squat it o g (9 b)

27

Force ()

Muscle

Moment Nm)

Compresson N)

Ser ()

Rctus a bdomini s

25

2

24

5

Ext rnal obl iu 1

45

1

39

24

Ext rnal obli u 2

43

2

30

31

Intrnal obl iu 1

14

1

14

2

Intrnal obl iu 2

23

1

17

16

862

35

744

436

ongissim us thoracis pars l

um borum 4

ong issim us thoracs pars  um borum 3

1514

ongissi mus thoracis pars lu mborum 2

1 342

ong ssmus thoracis pars l um borum 1

1302

1422

518

121

1 342

0

110

1 302

0

93

Ilioc ostalis lu mborum pars thora cis

369

31

369

0

ongissimus thoracis pars thoracis

295

25

295

0

Quadratus lum borum

393

16

386

74

atissi mus dors i 5

12

6

79

2

Multif idu s 1

36

8

1 34

18

Multif idu s 2

226

8

189

124

Psoas 1

26

0

23

12

Psoas 2

28

0

27

8

27

6

27

5

Psoas 3

28

1

Psoas 4

28

1

,

giv ots corrspond to fon, w ngiv sr corrspods o L4 sring posriorly on  .

Loads on the Low Back During Walking Thod of oweve od cyce e eded by he pe eve dy  wk Whe he m od  he ow bck d wk e    fe d oe be cvy cc hve fod h wk povde eef o ome vd    pf o ohe Rece wok h eed h wk peed ffec pe mechc d my cco fo hee dvd dffeece D wk he compeve od o he mb pe of ppomey 2. 5 me dy weh

0

Normal and njry Mechanics o the mbar Spine

  

Oi  

   Fas Nora So

100

 o

 a















4

4



















 

S ()





.   < &  

Fas Nora So

    - - -1 5

Si () b

 as 



 

oal Sow















4

4

-5



- -15

Si ()

c Figure

55 oads on t ar spin (noraid o ody wgh) drng tr spds o wakng and wih noral ar swing. T rvs ar norad or on srid (rgh l ona to righ hl onta)  (a) 4/ oprssion () anror/posror sar fors n wi posiv ndas antrior sar o  sprior vrtra ara sar or n w posiiv ndiats rigt sar of t spror vrtra.



JP

Reprnted from Clnal Bomehans, 14 Caahan AE Pataand SM McGi"Lo back three-imenona joint foe, knemat an kineti drin akin" 2032  61999ith pemi on fom evi er Siene

toether with the very modet her force re we beow y kow iitro fire od ee fiure 5 5 ) troi reduce pe moto d produce mot   ic odi of iue howeve whe  e wki wth rm wi cue cycic  od of tiue Ch Pt d cGi 1 ) e e fiu e 5 6 ) Th ch e  moio  my bei to ep he reef eperieced by ome Arm wii whie wki fter with  other ctor cotroed reut i ower umbr pie toue muce ctiviy d od ee fiue 57)  fct we hve obeed up to 0 eductio i pie od from rm w i ome idvdu Thi my be becue wi the m

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fitte effiiet toe d eovey of eti eegy edui the eed fo o et mue ottio d the uppe body eetio oite with eh tep o iteetig  the ft uefu tht ft wi hfom bee ow how to be  poiive ofto pevetio of d moe eovey b toube Nutte, .i

Fas Walkng t w i geey thepeuti  Nu tte 1 88) eve mehim ppe to out fo thi: eipo mue tvtio d tue od h ete moto d edued pie od with eegy oevy fom m wig  o tt, thee beefit do ot ou duig ow wig o m toig whih eebte ymptom i my eue of the tti od tht eut.

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57 Acivaion profies EMG signals) ro 14 orso uscles during hree speeds o waking wh nomal arm swing and noralzed o RHC o RH The msce pairs ae RA) recs abdons EO) eena oble inena obie LD) lassms dosi TES) hoacc ereco spinae ES) lbar eecor spnae and MULT) uiidus

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Low Back Dsorders

Loads on the Low Back During Sitting Naheo 66  tadia pee eaeet, doeted the hhe oad o the d  aio tti pote opaed to the tadig pote. Noa itti ae feo  the ba pie, ad peope, i eft ae eeay it i a aiety o feed pote Caaha ad MGi 21b. tti geeay ie owe abdoia wa atity patiay the deep abdoa  opaed to tadg ad eeay hihe eteo atity with ppoed tti ee Caagha Pata ad MG, 1 fo wak ad Caaha ad MG 2b f ittg. ttg ohed ze e atity whie itti oe pight ee hihe atia tio of t he poa ad the et eo  ke MGi  Kop et a ., 18.  e o ieae di a tee th pote ha poded d heati i the ab e . .  Wide Pope, ad yoye  88 I at, Keey 75  doeed a peif k betwee poed itti ad the dee o heati Moe pght ttg pote ad the ootat poa ad othe e atiati ipoe additioa opee oad o the pe. Chai ba pote ae a gatio of the oad fo oe te to aothe. Caaha ad MGi 21b eted that o ige idea itti pote eit; athe a aabe pte i eoeded a a tategy to iiize the ik f te oeoad.

Stting Postu re epite the yth pepetated i ay egooi dee egadi a e dea pote fo itti, the idea ttg pote  oe that otiay hae th peet ay ie tie fo aati too h tai ittig tatee ae peeted i hapte 8.

Loads on the Low Back During Flexion Exercises



Vey few tde oy o ow that we ae awae hae atied the tie adig o the ow bak tie d aio type o too eo eeie athogh e hae eaed the EMG atiity o  eeted e e . . .  i t 65 ; Hape ad ek 7 ette idey, ad Citti, 84. hi type of ifoatio aoe a pde iight ito eatie e haee, bt it i etitie fo dig eee peipti deio beae the etat pe oad i kow. The oa i to haee e at apppiate ee bt i a way that pae the pie. oo ay eeie ae peibed fo bak ffee that eeed the toeae of the opoied te  at I beiee that ay ooy peibed eio eee et i o h pie opeio that they wi ee that the peo eai a patiet o eape, the taditioa itp ipe appoiatey 33  abot 73 b of opei o the pie e ad MGi 17. ie 5.8 itate poa ad abdoa e atatio ee i a aiety of feio tak whie fi e 5 i  tate atiatio patte wth betkee itp adatiatio fie 51 itate atiatio witht betkee p tethat thatthe e ee ae epeed i patte oaized (% MVC. Thi ea atty i epeed a a peetae o what wod be obeed dig a aia o tay tatio MVC th atify atity i a phyioga ad f tioa tet. the, the pie i ey eed di the peiod of thi oad MGi, 8. The atioa ttte o Opa tioa aey ad Heath N IO H  81 ha et the atio it  ow bak opeo at 33 N epetitie oadi aboe thi ee  i ked with hihe iy ate i woke, yet thi i poed o the pe with eah petitio f the itp! Tabe 5.7 how the atfiato of a aiety of feio eeie.

Normal and Injury Mechanics o the Lumbar Spine

05

My rom pog tu with th k t th thoy g tht h o  rig o u opi o g r ph th po i hor o h ght io rtohip o tht th rutg for r ru Afr xg h  h  w fou th o  ut W l  gru of wo wo w  ough to fit t  MR r   th k  hi g whil thy w u gu  MG 15 . Th o   o h g it

Cross cul-up

Cur-up

som si suppo

Sragh-lg sup

i of  tio o ou   t i th  h trl oy  tr r  th ur pi i ori th  fw i u Th   o hg t  ro  flxor o  xt   uto f rh itrto rror ou o o i whh th o w rrt   trigh i pulr.  t h  w h oot ur  th lur  x  xt Futh r i t i tu h th o  hort  wth hp lxo ut  ti   highr uig k u uk MG Krf t  8 ot ow  h   ouy thouh. h i u h  flx torqu ut o ro owr  h ht po u ot t hghr 

Push-up om 

Bntkn lg ras

Oyn si suppor

Bn kn sit-up

Straight-g

f tio g t oo gh G th th itup ipo uh  rg ori o o th p rg f th g Prss-h ig  or trght th u  t whh ty situp of tu hou  ro thr t u hu ot  r  l y  o Fr tt wy xit t rr  som r han  u hlg w   g lw o I kn   Th who r rg for hh r  to po  itu o tg 0  0 20 30 40 50 60 70 80 for ro y g  rut y u uy opotig th to th ut Pcnt MVC Wh p  of th ook o k hto off pii rfrr xr   Psoas 1 g to  u  f xo x Psoas 2   w hr rt hgg t t r cus ab fr  or r  xg t  o r xt obliqu n oblqu t g  oft tho to o o   rans ab u th oy i hgg  ot o ro. T i uty o Th hgg xr  Avaon of he psoas and he adomna grt wl or  N of  trq msles in a varey of fexon ass om a grop o hghy Axlr  MG 1. Ti ro ot ained secs (ve men and hee women x oi tio h    o or for o  p  t 5.. r tt l    t  th  ri ho lr   iu i t  wt r  o . ais

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Fgure

59 civato -im hisos o h sam suc s as   fig 58 prfomg a k  sip  Sufac ad idwllig lcrod s ar  d cad

Hng te th hoe not nterete n prng ther k n who re rnng th perforne ojee y eneft fro the hgh po henge, toether th ret n n oqe tty. Cery the rp prr tret the ret oth pper n ower n genery oher exere ho e perfore to trn the oqe. oe he ggete  twn rp to ee he oqe, t th ret n  por rto o olqe e hene to pne opreon opre t the e rge exere Aer n MG, 17kng the e rge  preferre exere.

Loads on the Low Back During Extension Exercises A wth the exon exere e n he preo prgrph penty of EMGe te he expore extenon exere,  ony ne tepe t qnt the retn te . Exere prerpton  not e ef f the pne ong  not ontrne for  k. ng the rt pne pproh Cghn,

Normal and Injury Mechancs of the Lumbar Spine

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Psoas  ind Rectus abd sur Ex obiqe ind Int oblique nd Tans abd nd

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Time (s)

Avao-me sores o he same group peormng rlps.

G g  MG   8 at to rk xso xr ss o h s hg th st s oa a h ota to Th ky to rg  th t s tto  wh   th sp oa s to at oy o s of th s sat  t a t  Th pos s aoy to  har 4 srs h ftoa sarato of th thoa a ar oos of th osss a oosas. For th os of ths ssso w  thk of th xsors  fo stosrght a ft thora potos  rht  f a otos Th oo xtso taskxt of rfo torso wth gs r  th ar ppr oy or th xtso of a h o th Ro h f r 5  1 a  att s a for xtsor gs a tyy poss or 400 N (ao 80  of oprsso o th s E wos  h ooy r sr k xtso sk  s,  whh th pa s ro a xts th   ostrth rs  ths ga atats a fo xtso stos t os  to 6000 N (or 1300  o a hypx s (fg 5 Th s o jsf for ay pat Sra aratos of xrs thq  a ps ato

 08

o ak Dsors

Table 7 o Bac Momen, Abdominal Mus cle Aciviy , and umba Compessive oad Duing Seveal Types of Abdo minal Execis es Muscle acivaion Momen Nm)

ecus abdomins % MVC)

Exernal obliue

Compression N)

Straightg situp

148

121

70

3506

nt l g situp

1 54

1 03

70

3350

Curlup, ft anchord

92

87

45

2009

Cu rlu p, ft fr

81

67

38

1991

Quartr situp

1 14

78

42

2392

Straghtlg ras

102

57

35

2525

82

35

24

1767

89

67

2964

ntlg ras Crossn curlup

12

Hangng straight lg

107

90

2805

Han gi ng bnt lg

84

12 78

64

3313

som tric sid  bidg

72

48

50

2585

MVC corctos were isoetric Actvio ves higer th 100% e oe see durig dymc exercse

i oio o he eeo d ey e he pie o high od. o p keei o  o d eedi oe e  he hip ey iv o ide o he b  eo o ove 20% o i d ipoe oy 2000 N o opeio ie 5     Pe oi he bi ddog, i  whih he o ppoi   i eded   he hod  whi he e  i  ied e 5 1 1 d , dd ivi y o o id o h ho i eeo geey od 3040% o i d oi h i od o o 3000 N.  ddiio, he ei ehie how o hi ie i he ee ie p eiio h e hp e  3   e  o eh h oo o ye o oove iizi pe o d deii hee eeie e e 5

Dubious Lifing Mechanisms I h 15 d 6 i bioehi ed  pdo. h ie ie ode o he dy died h he pi wod be hed o h oi o iy dig ei iig k, ye whe peope eoed hoe k, hey wkd wy ied hi o ived eve eeh o  o heoize bo  ehi  h od o d oive  ee o he i . Reehe o oed he o eh i: h ibdoi pee hi, he bodo i ehi d h e hyd i  iie. A hoh oe h  vivd  iy ii vi e i ei  Noehee, oe opoe  povided ii h o qe dy d ed o h dedi h we hve ody. o hi eo hey wi e eviewed iefy hee

Figure

51 Specfic exesion exercses atfied o msce acvaio and te resuan spne oad (shown in table 58: (a) run exesion () proe eg and run extension singeeg exeson and sngeleg and cotraaea

(

am exenso (biddog).

()

±

able 5.8 Mean Actvatin eves 1 S)  1 4 EMG hannels  1 3 Sbects Peming a Vaiety  ExtensDminant Execises (Expessed As a Pecentage  MV) xtesi letygpi el

Rigt leg

Rgt leg and Left eg left 

Left leg and uk Clibti igt  d legs uk pstue

Right RA X

33

2.7

40

3.5

4. 7

3.1

1 .4

SO

2.4

 .9

2.0

2.0

2.2

.8

1 .0

Right E X

8.4

49

1 6.2

5.2

4.3

3 7

 .0

SO

4.9

1 .5

6.0

2.3

2.5

1.7

0.6

1 2. 7

1 .9

1 08

1 2

Right X



120

82

15.6

2.0

SO

6.8

25

8.2

42

10.1

Righ t O X

8

58

1 2.0

1 2. 5

1 1 .2

6.5

59

SO

5.4

3.5

96

6.2

4.3

4.0

85

RghES X

5.7

1 3 7

 15

46.8

661

45.4

2.0

SO

2.0

7.5

6.6

29.3

88

10.6

9.0

12.1

 ' 0

Tble 58

ct xteso

tomyop l"

Rt 

Right ES 

1 9.7

SO

9.

R t e  Let e et m

k

Clto post

2.3

28.4

1 94

59.2

57.8

4.9

0.2

11.0

1 1.7

8.5

4.6

21.9

1 0.8

31.5

16.

5.9

47.5

6.4

SO

6.3

6.0

8.2

1 2.0

4.7

2.3

5.6

ft RA 

4.3

3.6

44

42

6.5

3.7

2.2

SO

3.4

3.6

3.8

3.9

3.4

2.4

2.

ft E 

5.4

9.0

6.2

15.9

6.3

5.2

8

SO

20

3.8

2.5

6.6

3.2

5.2

1 .0

60

 1 .3

22. 6

15.2

2.5

1 .6

8.6

7.0

9.2

6.7

5.9

6.1

13

4. 5

50

1 0.7

6.2

9.2

5.

6.1

SO

4.3

4.5

18.2

4.4

5.

4. 1

8.5

f ES 

1 5. 0

4.5

42.9

10.5

63.6

41 .6

2.2

7.5

2.0

205

5.9

22.7

10.0

9.8

ft ES 

 1 .3

16.8

9.5

 25.5

56.8

57.0

233

SO

6.6

7.3

14.5

4.7

8.4

Right MF 

ft 

0

SO f O 

SO

ft MF  SO 

1.9 7.0



11.7

et e  k t m  s

4.5

7.4

1.0

22.3

16.6

33.8

573

533

6.

7.2

6.7

1 14

120

 

 

87 43

Eeroyogap i  a e: A retus abdois use, EO exeal obue use eal oblue usle D lassius dorsi use E toai eretor spae use  E lubar eetor spae usle MF ufidus usle Calbaio posure stadg uk fexed 60°, eua luba postue 1 0 kg (22 b ed i ads wit as agg sagt dow.

=

 0



Norma and nuy Mechancs of the umbar Spine



Intra-Abdominal Pressure Doe aaoal peu A play a ipoa ol i he pp f h la pe, epecally  eo lf a ha  lai fo ay ye aoia accay i epeeaio of he ole ie ha ee fla  h a he eeach o lifi haic ha foe a coeoe fo he ppo of aoal el fo ial wok a ha oae he pecpo of aoal ehe poa May eeache hae aoca h  f iaaia pe a chai o ly  la pi copo a 96 hoo 988 How o eeahe eie ha h l f    pal loa  ha ee  phaz e Gw, 980 Ka   a  , 9 

q

Anatomical Consistency in Examining the Role of Intra-AbdominalPressure oi Lca a ele 96 f opaioaliz h haic f h l ppal i a o a i i a f ollow izi  he aoe y o h gli a a ow ig a exeo ex hyalic foce o  h peli oo a p o he iapha, ceai a eile eec oe he l a pi o a lea allea oe of he copeio Mi  he ealy calcla f hi hyali peal w h fll ackwlee of he eceaY aoal acy oac  he aoal wal po exa op io o he pie   ela of he aof f ewee he exa aoa l cl cop  a  h hya lc elef epee o he eoeical apo ae oe of h ap appea o e oe of ioloical ealiy I fac expeeal eece e h oehow  he poce of ili p A he e copeie loa o he p  eae! Ka a cowke 986 oee iceae lo ack EMG ay h ceae A i oaY Valala aee Nacheo a Mo 964  aho, eo a chlz 986 hoe a ceae  aal p   Valala aee icai a e ceae  pe copeo h  ce  , pealy a el of aoial all clae acy   w igaio, i whih w  ou ial p oe e oe ha  pi opeo wa iceae fo he eceay cocoia aol  y o ceae A heoe he ize of he coecoal aea of h  ph a he oe a e o eiae fo ce a oe a he ow   lel poce y A hae a ajo effec o coclo eache ao h  f  MGill a oa 987 he iapha fac aa wa ak a 243  ,  h ci f hi aa wa pla 38  aio  he c of he T2  opa  h ale wh ho ue  oh  : 5    fo h pl f  45  fo h apha a oe a  ac of p o   4   whh  o h h  o people  qa lf h  effc of he il of he aial clae a A ee o e o iceae copeo h h alliae j la A aile ecipio a aalyi of h fo a i MGll  Na  987  hi ho a fi ag  wih he xpiel eiee f K  olla 986 who e EMG o eala ff f a  h ee f h exo o oa hy  a of h Naho colla 96, ho ocee ceae iaical pee wih a iceae  

Role Of lAP During Ling h aio of appecale A i lahali k  wll o h ol of A  o Fafa 973 gee ha A ceae a puze  cay o a a he h ooplke eoe of he aoa    ece k  h h hy eae he iace of he aoal o he pie oe a MGl

 2

ow Back Dsorders

Juke a Axle 996 wee uae o cof susaal chaes  aal eoeY whe acvae  a sa posue. Howeve h css paly of aal acvy cao e scu he spe appeas  e we sue o susa ceas copesso loas f sc sa y s ceas. A usale se ukles u exeey lo copssve oas e.. appoxaely 20 N o au 5  ucas a esle 196 he eey o he spal usulaue suss ha  vu a poes exe laea a a/pseo  foes  he spe ha a e huh f as uy wes o a as  peve e a cpessve ukl Chlwck  a McGl  1996 As we l acv ae ao a s eae a   cye f h uk esu  a sfe sucue Recey oh Choewk a olleaues 999 a G a coleaues  pess ocuee eas oso sfess u levae AP eve whe accou fo sla aal all cac levels hus ahouh he cease AP cooly osee u  a  ele expee ack pa oes o have a ec le  eu spal  pss   a  he exes e  oes sffe h uk a pee ssue sa  faue fo uk

Lumbodorsal Fascia Ree sus have aue vaous echaal oles  he luosal fasca LF). I pacua soe have suese ha he F eucs se lassv he paax e eale  a se have ecoee l sues ase o vaus peas f he echacs f he LF. Gaovesky Fafa a ay  98   ally suese ha laeal f ocs eeae y eal lque a asese as ae ase  h LF a he aahs  h laal  hey als cae ha he fasca cu supp susaal xs s FUhe laeal s fo aoal wall aaches was hyphesze  case l ual s fo Poisson's effect, caus he ps sus posses  v ehe esul  lua exes hs seque f eves e a aave pposo ecause he LF has he aes oe a f all exes ssues. As a su ay exes fes wh he F wul se he sales cpessve pealy o veeal cpoes of he se he epee sues hwve exae he echacal ole f he LF a clcvey qusoe he ea ha he LF oul supp susaal exs  s (Macosh a uk 1987  McGll a Na 1988; sh u a Eas 98) As pevously oe ealess of he chc f F ava saey he LF uo o he esav exeso oe as ele opae h he uh ae low ack ea oe eque  supp a la  he has s fu ay e ha  a exes usle ac u u uk a Macsh 98 Huks Aspe a Hckey 990 pose  hal ous ha he LF as o ease he oce e u of cssseal aea ha use a pue y u o 0% hey sues ha hs ease  fe s aheve y s a u  of he usles � he hey shoe. hs e as  pove. esh u a Evas 98 sus ha he LF ay  a f

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suppo aeal e Fhe hee s  ques ha he DF s vle  ha say of he lua cu see hape  N u ple assesse f hese os wl  pusu  he uue

HydraUlic Amplifir he fa echas hypohesze  ua copessv sesss f he sp as h hyauc aplfe hs hy has ees  he s Fs h lvae AP eseves he hlke eY f he aal all u x

Normal and Injury Mechanics of the Lumbar Spine

3

l

The u ao ee hydauc peu poeoy oe he p a puay houh o h uee of he luooal aca Fally a h o ucl a oa,  a popoed o "uk upo hoe aa a h hy aulc pue ue he faca Th ocha cal aaco of h pu  u he faca  ha ay lo ud a oc eae  h e aa u he  d fo h uely ul o coue eeo fo, heey ow h cop loa o h p oh of hee popoal  dd G h z of h faa hyaul peue oud ae ach lel o hud of H Pu of h aue ply a o oeed du eco Ca  a 195. Moo h peece o a of AP ake le dee o he hooplk eoy of h aoal wa McGl Juke a Ale 199) a h  oe oulae y h pou



AP, LDF, and Hydrauic Ampifier: A Summary AP he haa oe of he L, a h ec of he hyau aplf  popo o aou fo he paao ha popl w ale o pfo lf ha h pe ol ud woud cuh h pe  alhouh oh AP a h LF appa o pay o o  f oe of h he popo ha a a eale eplaao o h paao o uhed pe ud hay loa hh coee epaaly o coed h h oh wo Th po lay  h pl oe of h e a ou dcad e ao No oly we  he ahe opl ha  o pe h he eceaY al u alo he eh of h u o a oa a alo que uea  h ealy  ha u o aac aple ha ee cuh  afcaly  a of aeal ah ha au u oo aly

Other Important Mechanisms of Norma Spine Mechanics ea ohe feaue of pe echa uce fuco a ulaly up aee fo  ju po a ehal ao he o poa a p  he

Biomechanics of Diurna Spine Changes Mo pop ha peeced he ea o ak of he ok a h opa o pu h o  h o Th ual aao  pe lh h p  loe af a h d e) oh h he aly o e foa ha e ll oue Rlly Ty ad Toup 9) aue o   hh o a day of up o 19  Thy ao o ha appoaely 5% of h o ocue  he f 0 u af  Oe h cou of a ay, hydoa pu cau a  oufo of u o h  ul  ao o h pa  h ae hh  u eue o  h lae Whe a po l o a h oo pue  he d ulu cee he hyoa pu, au he c o pa Aa ola a Huo 97 o ha h a of lua flo a y 5 houhou h ay The cea lu o a  o  au h ua pe o  o a o e, hl h uulau  o appa o opeae y e  h e ae Aa a ollau a ha c ee  ae y 00% a la  y 80%  h o opa o h  hy oclud ha h  a a  k of uy o h ue wh  fad aly  h o Rcly ook a olau 99 oa ha ply ao ful lua flo  h o u ack ypo W  ae e o ua h  ha

4

Low Back Disorders

Exercise Peole sul no uneake spine exeisesaiculaly ose  equie full spine flexin o eninjus afe isin fo e en e elee issue sesses  esul is wou ol ue fo any occuainl sk equiing full spine ane f oin

Spina l Memo  Te funion of e spine is mouae y ceain eious aiiy Tis us ecause e oain is eemines isc yaion an eefe e size of e is sace an isc eomeY) wi in un moulaes liaen es eng oin moiliy siffness an loa isiuion Consie e fllwing senai: McKenzie  7 ) poose  a e nule us wiin e nnulu s ig as aneio ly uin sinal exension an oseily uin flexin MKenzis a of passie exensin f e lum sine wic is cuenly oul in ysial eay) was ase on e suposiin  an aneio oeen f e nuleus woul eease essue on e oseio poions of e annulus wi is e mos oeaic sie of eniaion  ecause of e iscous poe ies f e nuea maeial su esiioni n of e nu leus i s no i mmeiae afe a sual ange u ae akes ie Ka an cowokes 87) osee aneio een of e nuleus uin uma exension alei quie minue f n eae ex peien a lace aiooaque kes in e nuleus f aaei lua oin seens Wee is osein was cause  simy y  eisiuin of e eni f e weesa pe nulea aiy moin fw wi flexion o was a oemen of e wole nul eus emains o e seen onless y u ic eoY wou sues uin f es nf  e poseifannulus if e nul e enoi e ane lowe ioy  uin exension opessie ces wee aie o a is in wi e nuclea maeial wee sill poseio as in lifing iialy ae a longe eio of exin)  a concenaion of sess wul u on e oseio annuus Wile  i s speif  aea of e sea nees e eeloen  i  nsan sees o e assie wi e eisiuin of nulea aeial f is esul is e i wu l e unwise o lif an je ieiaely fllowin lng xin suc s siin  soin e a sooe ene sou no sn e n iaely lif a ey oje) uemoe as an Huon 88) sugse  lng ful exion y ause e osei liens o ceep wic y alw agin fexin osues o o uneke if losis is no onole uin susequen lifs n a suy f osei passie issue cee wile siin in a slue sue MGi an w n   2) sowe a oe e 2 inue s folowin 20 inues f f ul flexin sujecs eine only af of ei ineeeal join siffness En ae 0 inues of es se siua join laxiy eaine Tis finin is f iul ine f iniiuals wse wk is caaceize y yic ous of ful en ange f in osues f llwe y exeion  Bf lifing exeins followin a se sue  ae plone siin  a case cou e ae f sanin o een nsiusy exen in e sine fo a s peio llwing e nulea maeil  "equilia  oe aneily o a osiion associe wi noal loosis ay ees e fs n e oseio nuleus in a susequen lifin ask Liaens will ein se o ecie siffness uin a so peio of lua exension n conclusin  anay an eoey f e sine ae no sa i Mu eseac  ei ns o e ne  une sn e ipane f issue oain iso on susequen ioenis eailiin aies an injuy eanics

Normal and Injur y Mechanics o the Lum bar Spine

F u n ct i o n a l

115

of Spinal Mem

I woul appa po ci o ao loai  ealy af a u f polo flxio I  occupaoal wol i as eleace o aulac is fo xapl wo i o a acci sc wiou  luxuy of i  wa up o   pa iue) foe  lfi Ty wou  wis   w a lua pa o ao lua exo a  aocae cp T ac wo poi oo exaple a well uc a  o  ec f ai i play T wi eiie ack  wou  o wel o aoi i o  c wi a flx lua pe we wai o pfo We ecey quaif  s of coplia ce i  l ua pe w c ii ewee ou of alic p  Vsosfoac Ge, Geie a McGil i p i elie oleyal plays  i also a coiaio i polo pou ic "ial fici ica wi polo aic pou ii   way a  asocia cas  siffes a coiy i eal  ale pefoac a icas ei ik of ijuy We wil ae  iu o copleey i caps  a 9

Anatomical Flexible Beam and Truss: Muscle Cocontraction and Spine Stability T ooliaou pi i owa of a aaoical paaox i is a weai upi flxile o Oaioally e ailiy of  joi of  lua pi o e  ay iecio i accopli wi la aou f uscl caciai uc coaciaio pa ae coupucie o ea i  oqu csa o uppo  appli loa Coaciaio is also coupouci o ii  loa paly ip o e pie fo ucl cacio Reacs a psula

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seea iea xpla ucula coaciaio: e o aoial auppo l i  ao of iaaoal pu ai 959 i poi focs o  lua p a e luooa l facia (Gacoesky a fa a ay  9   s a a o ee wiou oppoiio ( peous cis Ao xplaaio fo ucula coaciao  eale A iaous spi will fail u cpei loa i a uckli oe a aou 20 N au 5  uas a sl  9 1 .  oe wo a a p  s uae o a c pssi loa!  pie ca  lik o a flexile o a wll uckle u copssi loai Howe if  o as uy wi coce o i like e ii o a ip as alou  copio i ul iaely xpce y   i  al  a uc o copi loa ce  is iffee a efoe oe esisa uckl T cocoaci usculau of e lua p e (e flexle a ca pe e ol of ailii uy wi ( u) o ac lua eea ac i aai uckli Rece wok y Cico a Pajai 990 oee wi Colewck a McGill 99 olwicki uluu a McGill 999 a GaMoe oks a ail 99 a u o qua ify e i ue ce of ucl aciecu a   csay coaciaio o l ua spi sai liy Te aciecu of ay o o ucls i s spcially su i fo e l of ailaio  Maco a  u k 97 McGi ll a Na 197  

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 o o ioke i aiuckli a ali ecai w lfi o coul uify lily cocoac  uculaue o iii  pa of pi uckli

6

Low Back Dsorders

nju Mechanisms Many nan ennee and eronomt beleve that redun the rk o lo bak n ury nvove the redut on o appled oad to the varou anatomal omponent  at rk o nj Wthout queton eduton o eeve oad  beneal but th  an overly mpt ve Optmal tue health re qu e an envelope o oadn not too muh o too lttle Whe ome oupaton eque ower load to redue the rk n edentay oupaton the k an e bette redued th moe oadn and van the natue o the loadn o dede whh  et the nan mut have a thoruh undetandn o th e bomehan  o nu ry whh ome n two part Frt  a be revew o the nj ury mehanm o ndvda t ue eond  a derpton o the nury pathoene and everal njy enao Alo needed  an undetand n o ene tuaton o low bak tue damae derbed n the tue ny pme at the end o hapter 1 

Summa of Specific Tissue Inju Mechanisms h eton povde a vey e depton o damae rm eeve oad Al njue noted ae known to e aeeated wth repettve loadn

• End plats. Shmor' node  ae thouht to be heaed endpate r atue Ve rnon Robet and Pe 93 and pt that om om oaled underlyn tabeular bone olape (Gunnn Callahan and MGl 2001 and whh are nked to tauma (Araal et a  1 979 n at Konb e ( 19 doumented (va MR traumat Shmo' node ormaton n a patent ollong  ored umbar leon that reulted n an njuy People apparently are not on wth Shmor' node the peene  aoated wth a more atve etye adatle Annear and Foter 992 nde eeve ompreve loadn o pna un t n the laoratoy  the e nd pate appear to be the rt ttue to be nured (Brnkmann Bemann and g 9; Calahan and MGl 200a Stude have revealed endplate avuon under eeve anteror/poteo hear loadn • Vrtbra Vetebral anelou bone  damaed nder ompreve loadng  Fyhre and Sha ler 199 and ot en aompane d henaton and annular delamnaton (Gunnn Callahan and MGl 2001 • Dsc annulus Sevea type o damae to the d annulu appea to our Ca d henaton appear to be aoated th repeated eon moton th only modera te omp reve oadn eque d ( Calahan and MGl 2001 a  and th ul e on th atera l endn and twtn (Ad am and u tton 95  Gordon e t a   991 nln an d MGl (999a and 1 999b doume nted avuon o the lat era annulu under antero/poteror hea loadn • Dsc nuclus Whle Bu kalter ( 1995  when reern to the d nuleu tated that "no other muulokeletal ot tue truture undegoe more damat ater ato th a e the relatonhp amo n loadng d nutrto n dereang  onentraton o vabe el aumulatn o deraded matr moleue and atue alure o th matr eman obure owever eently Lotz and Chn 2000 doumented that ell death (apopto thn the nuleu nreae under eeve ompreve load Interetnly thee hane ae enerally not detetae o dagnoae n vvo • Nural arch (postror bony lmnts) pondylt atre ae thouht to our rm epeated tetan revera aoated wth y ull leon and e tenon (Burnett et al 996 adate Annear and Foter 1992 Cpton and o leaue  1 995 and nn  and MGl (  999a ao dou mented that e eve hear oe an ratue part o the ah

Normal and Injury Mechanics o the umbar Spine

7

• Lgamen Lamens seem o vuse  lowe oad aes bu ea n her mdsusane a hhe load aes (Noyes euas and ovk 199. MGl 99 hypohesed h andn on he uoks rom a all ll ruue he nersnous omle ven he domened ores (MGl and Clhan 1999 nd jon oer ne aln on he behnd neases he rsk or poloned dsably (u Marn and Lloyd 91, whh s onssen wh he ooned enh o me  kes o amenous ssue o ean sruural nery hen ompared wh ohe ssues Woo Gomez and Akeson 1985

Reducing Tissue Damage Summrn njuy pahways rom nvro esn evdene suess h eu on n se ssue dame ould be omplshed y don he olon: 1 . Redun ek (and ml ve sne ompessve loads o redue he rs k o endle raue 2 . Redun reeaed spne moon o ull  eon o redue he rsk o ds  hernon (redun sne eon n he monn redues symoms 3. Redun repeed ullne le on o ulra ne eenson o redue he rsk o rs (or neua ah aure  Redun eak and umulave shear ores o redue he rsk o e and neura arh damae 5 Reun ss and alls o redue he rsk o ssve ollenous ssues suh as mens 6. Reun he lenh o me sn auarly eosue o seed vbon o redue he sk o ds henon or aeleraed deeneon

Injury Mechanics Involving the Lumbar Mechanism ny researhers have esalshe ha oo rea a load laed on a ssue l resu n njy Ede moloal ses (lkka e a . 990; Maas e a.  993; Norman e  a . 998; Vdeman Nrmnen and rou 990 have rven hs noon y enfyn ek loadn mesures (.e. shear omresson runk veloy eensor momen hevy ork e. as aors ha elan he requeny an srbuon o reorn o bk an  nease rsk o bk njuy oever he seah or re evdene ha lnks sne lod h ouonal Ds my have been hampere by ousn on oo narro a rne o vaables. Reserhers have ad a massve amoun o aenon or eamle o  snle vrbenmely aue or snle mmum eosure o lumar omresson. A ew sues have suesed ha hhe eves o ompresson eposue nrease he rsk o  (e.. errn e a. 1986 alhouh he orrelaon was ow. e some sudes sho h hhe es o Ds our when levels o lumar omresson ae resonbly lo. Wh ohe m ehan al vaables modulae he rsk o LDs? As noe n her 1  hey re as ollows • oo many eeons o ore and moon and/or prooned osures and loads

hve so been ndaed as poena l nuy or pan asn  mehnss. • Cumu lve lodn ( .e . ompresson she r or eenso momen has been den-

ed s a aor n he repotn o bak pan (Kumr 1990 ormn Wels nd eumann 199. • Cumulve eosure o nhann work has een lnked o reon o o bak n (olmes ukns an Freemon 1993 and nevereb ds njury (Vdeman Nurmnen and rop 1990.

18

Low Back Disorders

Many peronal ator appear to a et pne tue  oerane or eampe ae and ender n a ompaton o the avaable lteraure on he toerane o lumbar moon unt to bear ompre ve load Jaer and olleaue  199   noted tha hen male and emae are mathed or ae emae are abe to utan only appromaey o thrd o the ompreve load o male Furthermore Jaer and olleaue data hoed hat hn a ven ender a 60yearold a able to toerate only about to thrd o the load toleraed by a 20yearod o omplae the pure Holm and Nahemon 1983 hoed ha nreaed level o moon are beneal n provdn nutrton to the truure o the nterver tebral d hle muh o our ab reearh ha demontrated that oo many moton yle to ul leon reuled n nervertebral d hernaton Bukaer 995) aoated ntervertebral d deeneraton th dereaed nurton Meanhle Vdeman and oleaue 990 hoed that too lttle moton m edentay ork reulted n nerver tebral d n jur y W he orker ho per ormed heavy o rk er alo a nreaed rk o developn a pne nur orker ho ere nvolved n vared type o ork med ork had the loet rk o developn a pne nury Vdeman Nunen and roup 990. h preent he dea tha too lle moton or load or too muh moon or oad an modulate the rk o pnal nj In ontra Hadler 199 lamed that the ndene o bak njury ha no delned over the pat 25 year even ater nreaed reearh and reoure dedated o the area over that me rame Hadler ueted tha the ou be turned rom bomehana aue o nj  to developn more "om ortable orkpl ae Hoever the ork derb ed hu ar n th tet ha learly doumented ln k to mehana varabe Ceary BD aualy  oen etremely omple h all ort o ator nteratn We ll onder ome o thoe ator n the ollon eton

Into Pa ctice Whle the noton tha too muh o any atvty hether t be ttn at a dek r loadn heavy boe onto pallet an be harmul  dely aepted t  rarely taken nto aount n prae or eample ndutral eronom ha not ye hoeheartdly embraed the dea that not all job need to be made e demand n that ome ob need muh more varety n the pattern o muulokelea loadn or that here  no uh thn a "bet poture or ttn t  tm or th proeon a a hole to remember that n any ob the order and type o oadn hould be ondered and the demand on ue hould be vared Al ednary orker houd be auht or eample to adopt a varable poture that aue a mraton o load rom tue to ue redun the rk o trouble

Stoop Versus Squat in Ling Inju Risk Whle the ent mehod an prove hat a phenomenon  poble  obrved alure to oberve the epeted reult doe not elmnate the pobly One may ony onlude tha the eperment a nentve to the partular phenomenon The ol on duon a th many n h book atempt o norporate th lmaton and temper t th lna dom n a prevou eton ltn th the toro en abou the hp raher thn en the pne a anayed and derbed Spealy the lter eleed to mantan a neutra lumbar poture rather than allon the lumbar reon to le Here e ll reeamne the ltn eere but the ter ll e the pne uenty to aue the poror lament to tran h ftn tratey pne on) ha qute dramat eet on hear loadn o the ntervertebral olumn and the reutant njury k he

Normal and Injury Mechanics of the Lmbar Spine

19

domnan deon o he pas lumboum  o he lonssmus hoas and oosals umbou ul when he luma spne emaned n neual lods pag 6 aused hese mues o podue a poseo sha oe on he s upeo eea.  n onas,  h pn leon he saned nespnous amen omple gena os wh he oppose oquy and heeoe mpoe an aneo shea oe on he upeo eba s gues 512 and 513 ad. es eamne he spe oes ha ul m lng he lumba spne. The ued gamens appa o on ue o he aneo shea oe so ha sha o els ae lkey o eeed 000 N (22 lb. Suh lag sha oes ae o a onen om an nu sk epon. oee, when a moe neual od posu  adopd, he eenso musulaue s esponsle o ang h 512 hs gadeer appears to be adopig a ly lexed mba spie s his enso momen and a he same e pode a poe wse pose? The oce aaysis  fgre5.13 o sha oe ha pp he aneo sheang aon ggests i is ot o ay on he uppe ody and handhe la Th jon shea oes ae edued o abou 200 N au 4 l. Thus, usn muse o suppo he omen n a  neua posu ahe han en ully eed wh lamens suppotn h oen al dues shea loadn see ale 5.9 Quan aon o he sk o  n equ e a ompaso n o  h  apple load  h  l an e o he  sue. Cp on an d ollea us  995) ou nd h e shea o a n o h pne o e n he nehbohood o 2000200   n ad u adaes,  n  m ladng. Ren  ok y n ln and MGll 999a and  999 on pg pn

Fgure

ha hn ha load ae s no a mao moduao o shea oeane unls h load  e als uh as wha h ou dun a sp and  all . Th apl

a

b

Fgure

51 3 hese srca compte mage bmas om the expemet codced aond 987 illsrae he fly fexed spe aJ hat s assocated wth myoeecc slence i he bac exesos and srained posteor passve sses and hgh sheang orces o the mba spe (om boh eaco shear o the ppe body ad nespnos igamen sran (see ge425) A moe etal spne (J pose ecris he pas lmborm mscle grops . .  (otued)

Muse fores

Flexon/exenson

700 Re ab

600

 Ex oblque

  �

500 z 400

 

nt obque Lumba eretos Lat ors hora ereors

300 200 100 0 0

2

3

4

5

c Compresson an Shea ore

4

3 z

C

CMP

2

 SHRS

�

o 2

o

3

4



d

Figure

iue



513   spp e rec ser (see fgre 41 9)  d hs redces    she pprxel 2 N  s exmpe)

) (

Rerite rom Jounal of iomechancs 30 SM McGi"vited aer Biomechanics o ow bac ijury Im catios o crret ractice and the ci c" 4647 1997 with emisson  rom sevie Sciece  

0

Table 59 ndividual Muscl e and Passive Tiss ue orces uring ull lexion and in a More Neutral umbar Posture emonstrating the Shift from Muscle t o Passive Tissue The extensor moment with ful l lu mbar flex ion wa s 1 7  Nm produci ng 3  45 N o f compression an d 954 N of antei or shear. he moe n eutral posture of 1 70  m produ ced 3490  of comp ressio n an d 269  of shear.

ully fexed ar spie

Netra lbar spe

orce N)

orce N)

R rectus abdomn is

6

39

L rectus abdominis

6

62

R extena obli que 1

10

68

L extena oblique 1

10

Muscle

40

R externa l o bli que 2

7

62

L ext ernal obl iqu e 2

7

31

35

30

R internal obliqu e 

35

L nterna oblique 1 R int ernal ob lique 2

29

1 02 88

L internal obliqu

29

16

R par s lu mborum (L 1 )

2

253

L pa rs um borum (L  )

2

285

R pars lum borum (L2)

27

281

L pars umborum (L2)

27

317

R pars lum borum (L3)

3

327

L pars lumborum (L3)

3

333

R pars lu mborum (L4)

32

402

L par s lu mborum (L4)

32

3 55

R ilioc ostalis lu mborum

58

100

L iliocos tals lu mborum

58

1 37

e2



 2

Tble 59

ct Fully flexed lumbr spie

Neurl lumbr spie

Fore (N

Fore (N

 lon gissimu s thor acs

93

35

L longissi mus thoraci s

93

79

R quadr atus l um borum

25

155

L quadratus lum borum

25

94

 latssmus dorsi (L5)

15

101

L latissimus dorsi (L5)

15

15

 mutifidus 1

28

80

L multifidus 1

28

02

R multiidus 2

28

87

 multifidus 2

28

90

 psoas (L 1 )

25

61

L pso as (L 1 )

25

69

 psoas (L2)

25

62

L psoas (L2)

25

69

 psoas (L3)

25

62

L psoas (L3)

25

69

 psoas (L4)

25

61

L psoas (4)

25

69

0

0

Posterior l ongitudna l

86

0

Ligamentum lavum

21

3

Muscle

nnd

Anterior longitudinal

' 22

Norl nd Injury Mechnics of the Lub Spine

 23

ct

able 59

Fully fexed umbar spie

Neural lumba spie

Fore (N

Foe N

nnd R nernsverse

1

0

 nerrnsverse

1

0

R r

7

0

 r

7

0

R rr 2

1 03

0

 rr 2

 03

0

nersnos 

301

0

nersnos 2

35

0

nersnos 3

298

0

rsnos

592

0

R  oors s

122

0

  oo rs  s

122

0

>

demosaes ha he spe s a mu ch eae sk o susa   shear  000  apled o he jo) 22 b) ha compessve jU 3000  appe o he jo) (2 lb) s mpy eca use he spe s uy eed. For a more compeh esv e dscusso, see McG  1 99 he mar o saey s much ae  he omressve mode ha  he shear moe sce he sp e ca sa ey  oerae well over  0 k   compre ss o bu   000  o f shea  caus es u ry wh cyc oadg. h eample aso lusraes he ee d o c cas/e oomss o cosder oher oa g modes  addo o smple compesso.  hs eampe he real sk s aeo/posero shear oad. eesly, orma ad coleaues' 199 suy show ed jo  shea o e very mpora as a merc or rsk o ju ry of auo pa wokers pacuarly cumuave shear hh epeos o sufaure shear oads) ove a workay. e aohe cosderao mpes o he epreao of ury rsk he aby of he spe o ear oad s a fuco of he cuvaure o he se  vvo Fr ea le, Adams ad coleaues ( 199 suese ha a y f ee spe s weaker

2 4

ow Bak Dorde

 oe   odeey  exe   ree udy Gu g, C, d G 2001, owed   fuy exed pe u  oroe pore pe ode  200% weke  f  wee   eur poue.

Stoop Versus Squat So u  ee wre o e oop ye veru e qu ye of fg. Typy ouo were ed o vey pe ye  eue oy e ow bk oe. Te eo oe   fuo of e ze d poo of e o   e  d e poo of e eer of  of e upp e boy. A e expe deoe  uy ore opex e pevou ub pe urvue deeee eue g of eu o bewee e ue  e pve ue  ddo e dvdu ee e wy  w go  o e oved Tu, e pe ke oo pe oeer w e ue vo pe, evy fuee e e pe o d e y of e pe o er o wou dge. Te rk of u  e re ue  oved o of ee ype of ye, ye  w o dreed w ue de  o re  ore ouo

Motor Control Errors and Picking Up Penls Aoug  ofe e pe epor ure fro eey be k u  we pkg up  pe fo e foor)  peoeo w o be fou  e ef  erue Beue     woud o be eeed o pe be  y udo, e peroe rrey reod  eve. Ie ey bue e ue eewee oeover, we uy fo g xero  uderbe, expg  our we perforg u  k  o. Te foowg  wor oerg A u ber of yer o,   vdeo o opy for  g vew of e ur pe, we vege e e of power fer pe we ey ed exreey evy o (Coewk  G 992). e rge of oo of e er pe w bre  oze o fu fexo by fr kg te o fex  e w  uppor e uppe boy g gvy w o o  e . Drg e  toug te fer ppere owy o ve  very fexe pe,  f, e b o were 23 per

Fgure

514

A group of powr

rs ld vry vy wighs w hir mr vrr moion prns wr und Eh jon ws skiy onrod o fx u no fuly fx  join ws wy rom  fuly fxd lrd ngl (s fgur 55

2-3

Fgure

Ths fuorosopy mg o  powr  iftr's lumr spin sows how individl umr on moion n  unid in vivo Whil rordng n inry ourrd  n on ir wn h vrr  jus on join wn o is full xon ngl nd surpssd  y o on-l dgr. 515

o fro (ee fgure 5  fu fexo 5 1 5 . T exp ow ey o  f u fe o (up o 20 k or pp roxey 62 b) wo  e ure  re upee o e ke  fu ubr fexo

Norml nd Injury Mechnics

 the Lumbr Spine

25

owever, drg he eecio of a if oe e epoe dscomo ad pa. po eamiaio o he video uoroscop ecos, oe o he uma os spe cifica he L2L3 o) eached he f eo carae age whe a ohe os maiae her sac poso  23° sho o fu feio) he spie ced a aused u see fiure 516 hi is he rs oevaio we ow of re poe  he scec ierare ocmeg proporoae moe roaio ocu ri a  a sige  mar o hs u iq ue occre ce app ears o have ee due o a apropriae seqec o msce forces or a empoar oss o moor oo wsdom hs moivaed he wor of m coeae a ormer aduae sde Professor Jace Choewici o ivesiae a oous q ai   he sai o he u mar s pie hohou a wide vaie o oad a ss C hoewc  a M cGi  1996. Geera speai, he occurece o a moor cool eror ha res  a empora recio  acvaio o oe o he ieregmea musces (ehap, for eampe a ama o o sims,  iocoas, or mus) ma aow oaio a u a se oi o he poi a which passive or oher sses oud ecome iriaed o re Choewci oe ha  he s o such a eve was aes  whe  high oe were deveoped  he are mes ad ow forces  he sma iesegmea msces a osii wh or powe es) or whe a mse foe were ow sch as ri a oweve eeo hs   rom q ie o w es  ed g is posse Aams ad oa 1995 oed ha passive sse egi o epeee amage wh e momes of 60 m his ca occr sim rom a emora  oss o m uscar sppo whe eg over  hs mech aim o moo coo eror resg i empoar appropriae ea avao ea how i  migh occ  e eme ow oad sa os, o eampe g   a pec om he oor foowg a o a a wo peomg a ve demadig o

Figue

56 e power lfter fle xed to grb te weigt b a) nd begn to extend te pine duri ng te lt (b). A te weigt w  few ine rom te floor   nge  oint fexed to te ull exion  ngle nd te pine bucked indcted by te row



LL3

2 6

Low Back Dsorder s

Sou ces of Moto Conto  Eos noe isse st be consiee wen eaing wi e ossibilt of ckling ta resl ts fo specifc otor conrol er os  n o  cinical tesing we obs e silarl napropriate otor pates n soe en wo wee calenge b oing a loa in e ans wie breating 10% CO  to eeate beating (Cal enge beatng cases soe of e spnesorting scate to ro o naproria te low ees in s oe eole ; see McGil l Sarat an Seg in 199 ) Tese efcient oo contol ecaniss wl egten boecanica sscetibilit o inj o rein (Colewcki an McGill 199 M ab is crrent in oe n a lagescale longtina inesigaion to assess te ower of ese oo control araetes togeer wit soe pesona erforance ariables an eir roe in casing back inj oe a iear eio

Sacroiliac PainIs It From the Joint? ogk an coleages  1996) roe at so e low ac k ai n is fro e sacroiliac joint sef Te folowing scssion offers oter consieraions Te work at an ae reporte oe recent ears as eonstrate te extraorina agnites of forces witin t torso extensor sclatre een ring nonstenos tasks We tese for ces ae een in terrete for e r ecanical role cl incian s ae exres se nteres in teir oential to case inj One ossibili wot coniering is tat te ig sc la foces a aage e bon aacens of te core soning sce tenons. Sc aage as eras been wrongf atribte to ateate ecaniss One sc exae folows ain in te sacoiliac region is coon an ofen arbte to isores of te sacoiac (S) joint itsef or e iliolar gaent For s reason te roe of te scatre a ae been neglece. I is known at a lage ooton o e exenso sclare obtains its orgn n e S an posteror serio iac sine ( SI  egon ogk 1980  Te area of ten oneri oste ata cen  an exensor aoneoss s eael sall n reation to te ole of scle n series wit e tenon coplex. Fro  a potesis eole at te seeing isatc of arge sce isse to sall atacent area fo connecie isse aces e connec ie tisse a ig rsk of sstanng icrofailre restng in ain (cGill 987 Knowlege of te colecti e scle foc e ie istores enables specaion abot onete faire loas an clate taa For exaple if te foces of sces ta srcinate in e S region are tallie for te trial illsrate in tale  (age 93 ten te otal for ce trans ite to te SI region ring peak loa wo exc ee   k N Sc a loa wol lf a sall car o e gron! Te fae toleance of ese connectie isses is no known wc akes seaton oer e otena for icrofaire ifficl. No obt te rsk of aage st incease wit e ncrease n e extreel large loas obsere in te extensor sclae an wt te freqenc of aication. Insrial tasks copaable fting



ree conainers in excess 1 kg (0fo l) clatie er nte traa oer anisegto nsal sggestng ta teofpotenta signifcana are no Ts ecanica explanaion a accont fo local teneness on aation associ ate wit an of te SI snroe cases. s wel sce stan an sas often accoan SI an Noneeess reaent s often irece towar te aiclar jon esite e exree iffcl n iagnosing te jont as te pria soce of an Wile rection of spas trog conentiona tecnqes wo rece e ss taine loa on te aage connecte fbers paients sol e consee on ec niqes to rce inernal scle loas rog effecte fing ecanics Tis is a

Norma and nury Mchancs of th Lumbar Spn

17

nl x f w ere  b rl n w knwlg f nul ul r  re wul ugge  n fr njur r    n bl lreen l ul b rerb

Bd Rst and Back Pain Wl b r  fln fr r  r en  genrl r n ue  n fr r u  ju nw rn  be uner A ne n e 1 1 3 b r  ru   le l r) bl    rure run n  ne nfw f fu Mll n Wjk   16 Ml n ler 6) uene  grw n n lng r e uul  ur  b re n n r nnu be re r nr 32 ur T  unuul un rur n  ue  u bk Ogn n llgue   ) uene nr nerl n n e rbr e lng rlng  rl elene;   nbe beue r bn l nrl en  n   n w ue  l wn bn n rne  ger l; n   e er  w u   wln  T nlg n e  lng n b fr r lnger n g r ul r  n

Moeration in All Th Te r "rn n ll n r  nue  l  ne benl ; n lng ug nn nge n   ufbl Obul er  rbl bu e reu exl   n lng n be  ln  rble nre nnulu nl n e brl re

Bnding and thr Spin Motion Wle e rrr  ru  rnn unr nl nn (eg n   1) Clln n Ml 200)  bn bl  n enl ru  ernn b kng  ne n n l rn en n wrkr. ell  nl  eY e un  ne ren r  e  be rqur nl 800000  r 77220 b) bu e ne n u b rel fex kn reee r/ne flexn fr nnul bnng   full flx u e e   ). In e xren w un  r  gr rkng   nuleu er rln err rug  nnulu f   w fnl equern   nueu er  w ne  ur run 1800025000 e f flexn  lw lel  ne ren bu 1 000 , r 220  b)  b u  wul  ur  u  fewer e   bnng w gr ulneu ree l (bu 5000 le w 3000  r 670 b f ren) M nrn w e f   rkn  nulr rl n r e n n ll wrk rl uwr ung    ben  ln rkr re  e ben lle nn  uue g unl  ulnng een

Repeate Sp ne lexion Wle u ern efr  ben n run ne l   beng lerer  ree ne fexnen n e bene f ere ll le  gn ruble. rn guelne wl be re ef ne fr fr lxn ren r nlu

 28

ow Ba Dsorers

Confusion ver Twisting Whe tn ha been name n everal tue a a rk faor for lo bak njury the lterature oe no make e tnton eteen e knemat varable of n an e kne varale o eneran ttn torque. Whle many epemoloa urelane tue nk a hher rk of B th ttn tn t lo tt moment e man reult n loer mu e atv ty an loe r pne lo a (MGl  1 . Fu rther pave t ue loan  no ubtana u n the en o te t ran e of moon (unan an hme 1 Hoever eveopn tn momen lae very are ompreve loa on the pne eaue of the enormou oavaton o the pne muulature (MGl 1. h an alo our hen e ne  not tte but n athe neutra poture theorably o tolerae loa varable  her.oEther ne varae knemat an ofhh n eneratn he kne  torque hle no ttn eem e anerou an epemooal urey u e Hoever elevate rk from very h tue loan may our en te pne  ully tte an there  a nee to enerate h ttn torque (Gll  Several tue ten have uee that omreon on e lumbar pne  not te ole rk faor Bo aboraory tue te an e uelane uet that hear oan of e pne oeer  are t oupe h ttn orque  nreae the rk o tue nury.

Is Vira Invovement Possibe in Low Back Pain? Reearh ha uete that e nene o ome muuokeleta orer o te uper exremty are eevae  olon expou re to a vral n feon. Coul vral nfe tn ao be reponle or lo bak orer? Wle h enaro  poble n nvua ae t oul ony aount or ome Sne anma moe ue ue anma a are reene or eae t only approve pemen ben elete fo ten onrole mehana eem to aount or o heevelopn nan fnn Vra neton ave eenloan nke oul to an nreae probablty u eae a arpa unnel ynrome or ar (Moy an Cam 7 lp 17; Sam et a.  Hoever Rono an olleaue 17) foun at okreate ao r aoune for the majo ry of te au e attrute to evelopn ara unne ynrome. Fuure reear ou examne he lnk beteen vra nfeton ean o pnal tue eeneraton an o ak njury eoloy ey eem to be nvolve n ome ele ae

Section Summa From th erpton o njury meanm th everal moulatn fator   ear tha mutatoral lnk ext nterpretaton o thee nk ll enhane njury reventon an rehablat on efort. n fat e etve nerenon l no our u an unertann o ho e pne ork an ho t beome nure

Biomechanical and Physiological Changes Following Injury Wh le th e ounaton for oo l nal prate requre an unertann of te mehanm or nj an unerann of the nern onequene  ao hepul

Normal and Injury Mechani cs o the umbar Spine

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Tissue Damage Pathogenesis Pain and Performance any d pne injy a thogh   a tai enty that i y fong n eifi te daae. Howeer ne te dae e han e to the j on ieh n  her te wil e aeed and drawn nto the lnal pre nderndin the ln in h ie egin wth the onep o pan e da ae ae pain Soe hae ad here i no proo tha h i teen i te ne ain  a ereption and no inren an eare it drety. hi ntin gnore the are ody o pain literae a reiew  whh  wel otide the pe f th haper) whih h otited a reen propo fro a diere g  pn pelt to aiy pan y ehanpefialy ranen pn whh de not prde lner eqeae) nd ie njy and nero ye injry pin oth o whih he oplex organ ehan Woo e al 18) Siddl nd Coin  1) wonde rly aried he gre at dan e de  n the ndertndn of the neroiooy o panin patilar he longter hne r noxio laion nown a entra eniaion Briefly tie dage diretly afet the repone o he noieptor to fher tlation oer onger period f tie oth inre ae the ande of the repone enitiity o the t l nd ie o he regn ered y he ae aeren Soe linian he ed i   rti nae r the preription o anale early in ate BP Fherore oe he aed argent on whether a etan ie old nate pan ro the preene or aene of noieptor or ree nee endn reqirn proof of daae to the pe  te in qe ton  tie dae aon g a onn  f el dge to trtral ailre) hane he oehni o the pine o only y h hnge ae pan t t appear to nate a aade o hange h n e dirution o the joint and ontna pan or year n leading  ondtion h a fae arhrti aeleraed annlar deeneraton and nee root irritation t ne  few (See KiradyWilli and Bton 2 for an exelent reiew o the ade of pine degeneraton initted y daae) Bter and oleage 10) dened tha d dae nearly away ou eore fae arhrt  oered njy and tie daage iniate jont naitie aing he ody to repond wh thrti aty to f nally taile hi re in a lo o rnge o oion and no d pan (Brnann 185)

njury Process: Motor Changes It  onie hat paent reporng deilang low a pain fer iltne hange n heir otor ontro yte. Reonin thee hane  otant ine ( ) proded qte  they afet the tailing ye Rihrdon nd oworer orehenie reew of h leratre nd ade a ae for targetn pefi e grop drn rehaitton Speialy their oeie  to reedate faly oor onrol paern potinjy he hallene i o ran the alZing ye dring eadyae atie and alo d uing rapd olntay otion and to withn d dden rpre oad Aong the wde ariety of otor hange reearher hae dented they he pad ailar atention to he rane re adon and ltd le For exaple drn antipatory oeent h a dden hoder lexon een he one of ranere adon ha een hown o e delayed n hoe wh  roe (Hode and Rhardon 16 Rihardon e a 1) Sh deyed one

3 0

Lo Bac Disodes

f ifi tor u uig u  o a Riharo 1 1) ou iir th iit of h pi t ahi roti tiit urig  iutio uh   i or f h Qua gru o a rhaiitatio rt ifia i to rua th tor oro t for io of th trr ii A ur f ratri ha ao u hag t th utifiu px Furthr i a r i u of  ti ih hitri of hri BD ragig fro 4 oth to 2 ar iho  gu  ot that 50% ha it i io  75% of tho with riatig i h ar  troogra t h  ia pi xor u . Irig ough i h a ui o th u tiiu  EMG aoraiti  i h or atr  giu  o ar a g with th  i  uifiu i  tho with ak tru ig t    1) Jor  Nioi ) oiat or ura i th i x r i gr whi Ro a oagu 5) tih fr fatigu rt i th u tifiu i tho with  ak tr u. I aitio hag i tr goit atgoi tiit uri gait Artio  . 5) ha  u gthr ih atri xtor u uu urig ikiti tor xtr  Grir Kh  a Ghazawi  2 , whih ar i  tiu  ig. Furhr i  iia  tha h truur of h u  it f xri hag fi iu or i i Aatia hg fig  k iur i u atr troh i h utifiu i Rihro  Ju 1)  fr t hg i uifu  fi ar aftr urg Rat t  3 ogr ou  it ih rtai oiti hartrii. ifi a  go ut a aoit wih ora fi r apara hi  r ou o w oia with trph i th t  fir   tht ar i  I fir Moror  aftr to ha ro i a gu ) ut a r utifiu  ugg iir rfx a  h i. hi hor ar a i ou i f thi t thr oit rtiur t hhai k a Dixo  ok  th oug gi th iia o ha utifu a w  u uk 4 of thO rrh ha  rfor o thi u  rarhr wh ha xi thr u ha r iir hag i uiatra arohfor x  h  Dagria a h 1) hi oio of i trog uport xri rritio th roo h attr f uur otrati or i fit i  uit rfu u hurhia hg i with hri L O gi th hag r atig arot 6 t 12 k!

Other Changes Or th t to r  h xti tt 2 orkr. Of tho rkr 2 h  hitr of ak tru ufit to ru i ot ti 24 ha  k tru u  r ough t r o workti  h rt h r h  ak oi Our ujt   fiig out tai quiair that r u ifratio aout ograhi hi a at rk o tifati  ro otro work rgizti ri fi a riit tti. hi a fo i th prxi at f ur hou o f   ttig. hi iu rhi tig fr it artr o a ix r trgth fxii it O x t   r io f piifi arr trgh u ur thriioa oup oio u ug urig tak rquirig tti  uxt aig atiiao raio hag rthig ur tr ifig fr th foor t). hrughout  t ut r t itrut to out thriioa uar pi i 3PACE Phu Chr Vro a r uutur iit 4 ha f urf EG

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Norml nd Injur y Mechnics o the Lumbr Spine

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O g ae mmaie ee  Haig a o o low bac tole wa aocae wi a lage wai gi a geae coiit otetial a pece fm oocial qeoae a ebe exio o exeio tet a eace ato amog e fat.  Toe wo a a ito o ba tole a a lac o mle ea eifiall  a aace o eace amog to o mce op  l te  egt wa o elate alto e ao of fexo o exteo eg wa ima.  Toe wi a io o ow ac tle a imiie  exteio a itea tat et oa ioleme.  Toe wt a io of ba tobe a a wi e vaie of mo o  efii ilig ig alee beai (a wo occ g allegg w baacig ai o ee pie oaig a o o Geeal o wo wee oo i oe moo ta wee lel to be oo i aote.

Gie at toe woe wo a mie wo beae of a le wee meae 261 wee o aveae ate te a iabli eioe mlie efici apea o emai fo ve eg eio. Te oa imlicaio o ti wo i ta avig a io o low bac ole eve we a aial am of time a eae i aociae wit a aiet of ligei eiit tat wo e qi e a mltil ia ieetio aoa  o mi  te ee Wete tee eficit wee a ae o te tole (ea te co ave exte  to te mtom o a coeqece of te te emai to e ee  lgitial t bae o tee aiabe i e wa.

References das,  , and lan, P.  1995 Rc nt adva ncs n bar spnal cancs a nd tr lncal snfcanc. Cnical Biomechanics, 0 : 3. das, , lan, P. and Htn,   987 a varatns n t sr sss n t lar spn Spin 2 2 30. das, ., and ttn 95 Grada dsc prlaps Spine 0 24 das  and Httn, 9 cancs  f t n bral ds c. n: Gs P  d. , bioo q/th interveba disc.Bca Ratn, F: CRC Prss das,   cNally,  .S.  Cn n, H . , and lan, P   994 P str and t cpr ssv  strn t  t lar spn. Cinical Biomechanics 9: 5-4 rawa , N  , av r R., a r, S. , and atr ,  N   979  st dy f cans n t spn n gtlftrs and tr atls Bitish jou a q/Spo Medicine, 3 58-. rndtNlsn, L Gravn-Nlsn, T., Svarr r  , and Svns sn, P  995  T nfn   lw ack pan n sc actvty and crdnatn drn a Pain 4 23-240 stn-lr ,  ., and Scltz  .B .   9  cancs  f  an spn and trnk n: Pand l,

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32

Low Ba Diorder

Bouk, , Drb, R, Aril!,  Loui, , nd chwrzr, R 99 rciion dinoi n inl in. n: Cmbll, J E Pain 996An updaed iew 33-323 l: A r Boduk, , n Mcinoh, JE. 984 h lid nom o h horcolubr c. Spine 9: 4 Brinckmnn  98 5 holog o h  vr br column gnmis 28: 23524 4 Brinckmnn, , Biggmnn, M, nd Hilwg, D 988 rdicion o l coriv rnh o humn lumbr vrbr. linial Bimehanis 4 ul. 2. Buckwlr, JA 995 in ud: Agn nd dgnrion o h humn inrbrl ic. Spine 20 30734 Burn, A, Kngur  M, Elio, B C. , For, D H , Mrh ll, R  , nd H rdc l,   99 T ho rcolumbr dic dgnrion in oun  bowlr in crick A ollowu u linial imehanis : 30530 Bulr , D , r mow JH, Andr on GB  Mcil, TW, nd Hckmn, M. 990 Di d n r bor c Spine 5:  -3. Crr D, Gilbon, L., rmr J Krg, M nd o M 985 Lumbr rinl cormn ndrom A c ror wih hiologic nd nomic udi. Spine 0: 8 Cllhn, .  , Gun nin, JL ., nd McGill  .M. 998 Rlon hi bw n lumbr in od n d mucl civi durn nor rci Phsial ea78 : 8-8 Cllhn, J n McGill M 200 nrvbrl dic hrniion: udi on  orcn modl od o hghl riiv lon/nion moion wih comriv orc linial imhanis  28-37 Cllhn, J, nd McGill, M. 200b Low bck oin loding n kinmic urin nin n unuord iing. gnmis 44 4: 373-38. Cllhn, J, l, AE, nd McGill, .M. 999 Low bck hrimnionl oin orc, kinm c n kinic urin wlking. linial Bimehanis, 4: 203-2. Cholwicki, n McGill, .M. 992 Lumbr orior ligmn invovmn urin rm hv i im rom uorocoic murmn junal fimehanis 25 7 Cholw cki,  , nd McGil l,  M 99 Mchncl bili  o h in vivo lubr in: Ilic ion or inur n chronic low bck in linial Bimehan is   -5.



J





Cholwic ki,   McGil, M , n  99and  Lumbr in lo d urin li. n rml hv wih. Mediine andormn, Siene RW. in Sps ise 23 0:  79   8 Cholwcki,  uluru, K, nd McGil  M  999 Th nr-bominl  rur mchnim or bilii ng h lumbr in. junal fBimehanis 32 3-7 Chol wicki,   uluru, K Rbold  A, nb i, MM , n McGill M  999 Lub r in bi cn b umnd wih n bdominl bl nd/or ncrd inr-bdominl rur. upean Spinejunal 8: 388395 Crico, J  nd n b MM 990 our bomchn ic bili n gro  muculr rch cur Mulle ul semsw Yk: in h in . 438 n: Winr . n Woo,  E. ringr-Vrlg Cron, , Brlmn, Virino H , Bgmn,    ol, L, n r,   995 R on o h umbr in du o hr odin n: Inu penin huh imhani   Droi: Wn  nivri Dnri, TR, nd h O 998 Chn in crocionl r o o mor ucl in unilrl ciic cu b dic hrniion Spine 23 8: 92893 Dvi, R 959 Th cuion o hrni b wighliing Lane 2: 55 Duncn A, n Ahm, AM. 99 h rol o il roion in h iolo o unilrl ic rol: An rimnl n ini-lmn nli. Spine, : 089 - 09.

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U

Frn H.. 973 Mehanial disd fh lw bakhildlhi: L n bir Fin, M.M. 95 Abdominl mucl nvolvn during ormnc o vriou or o i-u rci: Elcromorhic u A meanjunal fPhial Mediin 44: 224234 Fhri D. n chlr, MB 994 Filur mchnim in humn vrrl ncllou bon ne,  5 05-09. Grdnr-Mor M., ok, .A.F., Lbl, J 995 Rol o h mucl in lumbr n bili in mimum nion or. junal fOhpaedi Rseah3: 802-808 Goron .,  l. 99 Mchnm o dic ruurA rlimn ror. Spin, : 450. Grbinr, M.D. Koh, T., nd Ghzwi, A.E 992 Dcouling o bilrl ciion in ubc wih low bck in Spine 7: 29-223

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Nomal an nry ehanis o the Lmbar Spine

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Graovesky S. arfa H, ad amy  (981) Meaism of te lumba spi. pine 6   : 249  Gren, J, Grenier S ad MGill, S (i press) Grier, S, reuss, R, Russell, , ad MGil SM  prss) Assoiations beteen low ak dail ity equellae ad finess variabes Gre  D  1980) tra-abdomial pressure r espose o loads applied to te torso i oma su jes pine 5 2) 149 Gunnig J. Calaga J ad MGil S.M (2001) Te roe of prior loading isto and sial poture o te ompressive tolerae and type of faiure in te spine usg a orine trauma model inical iomechanics, 16 (6) 471-480 Hadr ,  M  1 991) Isurig agains t ork apa ity f om sp al disor drs  : mo yer,  W  d  Te adu spine(pp 77-83) Ne ok Raven ress Haig A   eBre k, D. B.  ad oley  SG .  995) aaspi nal maig Quantifi ed nd  tromyorapy of e paaspia musles in pesos witout lo bak p an  pine 20 (6) 75-7 2  Cinica OhoHalp AA ad Blek, E.E. (1979) Sit-up exerises: An eletromyograpi study. paedics and Relaed Reseach145 172-178 Hardastl  Annear,  and oster, D 992) Spial abnormaties in youg fas owlers. Jouna ofBone a ndoin uge 74 3)  421 . rn GA. aaiedi M., ad derson, K. (1986) dition of oveexerio ijues usig iome anial and psyopysal modes Ameican Indusial Hgiene Associaionjoual 47 322-330. Hds ]A Riardso, A, ad ul G.A 996) Mutifidus musle reovery is ot automat followig esoluion of aute frs episode lo bak pa. pine 21 2763-2769. Hilkka, R. Matsson,  Zitig, A Wktrom, G. Han K, ad Waris  (1990) Radiorai ally detetable degeerative ages of lumba spie amog oete reinfoemn wkr and oue painters. pine 15 114-119 odges .W ad Riardso, A 996) I eient musular sabilisaion of t e lumbar sine aso i ated it o ak pa  A moor onrol evauaion of trasv esus adomiis pine 21 2640-260. Hodges W, ad Rardso A 1999) Altered ruk musle ritmen i pople t low bak pain wt upper limb movemet at diffret speeds A chies !Phsica Medicine and Reabiiaion, 80 0051012. Holm S  a nd Naemso A. (1 983) Variaios i te nutrtio o f te anine  tevrtebral di indued by moto pine 8 866-874 Homs A.D Hukins DWL ad Freemot, A. (993) End-plate displaemet dui or sion of lumar vertera-dis-vertebra segments ad te me asm of falure. pine 8 128-3 Hukins D .W.L. Aspde RM  a d Hikey, DS .  1990) T oraoumbar fasa a ine ase e e fi 30 iny of t eretor spinae musles. linica iomecanics 5 aer, M , Luttma  A ad aurg W  991 ) umbar load du ig oe-a nded briklay in Inaionajouna ofndusial gonomics 8 261-277. ayson M. and Dixon A (970) ra-ariula pressure n reumatoid atrii of e kne I essure ages dug joit use A nnals ofhe Rheumaic Diseases 29 401-408 ett   Sidney K  ad Ci utti   1984 A rial analysis of st-ups: A ase for te artal  -u a a s o msula edurae. anadian jounal ofPsical ducaionand Recaion, et-O -9 ogense K and iolaisen T. 987) Truk extesor endurae Deermiation and ration  ow ak trouble gonomics 30 259267 ur D MGil SM ad Kropf . (1998) Quaitative itramusuar myoeleti ativity of lumar orion o psoas ad te abdomial al durig ylig ouna ofApplied iomechanics  4 4  428-438

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ukr   MGil S M  Kropf , ad Stf fe, T.   998) Quaitative inramusular myole tr ativ ty of lumar portos of psoa ad t abdomnal al durig a wide variey of ak Medicin and cience in po and ecise30 (2 301-31 Kelsey ]L. 1975) An epidemioogia sudy of t elaiosi etween ouaion and ut erniate d uma  tervertebra d ss. Innaionajouna !pidemioo 4 197-205 Kirka ldy-Wi llis W .H  and Bu rton C ( 1992) Managing low backpain (3 ed.. New ork Curll Lvingstone pine 13 934-935 Koe M. (988) MRI diagosis of traumai Smorles nods. Krag M.. Byr K.B. Glbertso, G, ad Haug .D. (1986) ailure of itraadomnal reur zatio to redue reor spiae oads dug liftg tasks (p. 87) In Poceedis ! e No Ameican ongess on iomechanics,Motreal August 2527

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o ack Dsorders

Kag M. Seoui E. Wide DG ad ope MH 987) ea diplaeme ditibutio fm i vito loadig of huma thoai  ad l umba pia moio egme t: xpeimetal eult ad theoetia pediio pine 12 0): 1001 Kuma S 990) Cumulative load a a ik fato fo bak pai pin 15: 131-1316 Lotz .., ad Chi ]. (2000) terveteba di e death i depedet o he maiude a duatio of pial loadig pine 25 2) 1477-14 83 Lua D ad Bee B (961) Stailit of he ligameou pie Teh Repot o 40 iomeha i Laboat Uiveit of Califoia Sa Faio Matoh .E  ad ogduk   198) The m opholog of he lumba ee to pia e pine 2 7): 658. Maitoh ]. ogduk  ad Gaovetk S (987) The biomehai of the thoaolumba faia. linical iomechanic 2: 78 Mara WS. Lavede S.A Leuge SE e al 1993) he ole of dami thee-imeioa tk motio i oupatioall elated lo bak diode: he effet of okplae fato tu poiio ad tuk motio haateii o ik of ijuy. pine 18: 67-628 linical iomchan ic 2 3: MGi S.M. 987) A biomehaial pepeive of ao-iia pai 145151 MGi  S M  ( 199 1)  The kieti poteia o f the lumba k muuatue about hee orthogoal othopaedi axe i exteme potue. pine 16 (7): 809-85. MGi S M   997) Ivied pape: Biome hai  o f lo bak ijuy  Impliato  o uet pat ie ad the ii. jounal oiomechanic 30 (5): 465-475. MGill SM (1998) Ivied pape: Lo bak exeie: videe fo impovig exeie egime. PhYical eap78 (7): 754-765 MGi S.M  ad le  996) Chage i pie height th oughou  32 hou of be et: Impli atio fo bedet ad pae tavel o th e lo bak. Achie oPhical Medicine and Rehabili aion 38 (9): 925-927 . MGil S.M. ad Bo S. 992) Ceep epoe of he umba pie to pologed lumba flexio linical iomechanic 7: 43 MGil SM ad Callagha ] 999) Impat foe folloig he uexpeted emoval of a hai hile ittig. Acc iden Anali and Peenion  31 : 8589 MGill SM uke D ad Axle C. 996). Coetig tuk mue eomer obaied fom RI ad C a of upie poure fo ue i taig potue jouna oiomechanic 29 5) 643646. MGill SM va Wijk M Axle . Gletu M. 996) Spial hikage: I i uefu fo evaluatio of lo bak load i the okplae? Egonomic 39 (1): 92102 MGill SM  uke D . ad Kopf .  1996) uatitative itamuua moeeti ativ it of quaatu lumbom duig a ide vaiet of tak linical iomechan ic  1 (3): 170  MGil SM ad Kippe V 994) afe of load betee umba tiue uig he lexio elaxatio pheomeo. pine 9 9): 2190 MGill  S.M . ad oma W. ( 1987) Reaem et of h e oe of itaabdomia pe ue i pial ompeio. Egonomic 30 1): 1565 MGill SM a oma W. (1988) The potetial of lumbodoal faia foe to eeate bak exeio momet duig quat ift jounal oiomedical Engineeing 10: 32 MGill SM Sharatt M.. ad Segui ].. 995) Load o pial tiue dui imultaeou iftig ad vetilatory halege. Egonomic 38: 1772792 MGill S.M va Wik M Axe .T ad Getu M (1996) Spial hikage:  it ueful fo evaluatio of o bak load i the okplae Egonoic 39    92 -102 MGil l S.M Yiglig V  a d eah . (1 999) hee dimeio al iemat i ad tuk mu e moeleti aivit i the elde pie: A daabae ompaed to oug people Cinicaliome chanic 14 6): 389395 Ga he K M  Mille ]AA Shultz AB  ad Ade o GB ]  987 oad dipl aemet be haviou of the huma lumboaal ji jounal o Ohopedic Reeach 5 488. MKezie A. 979) ophaxi i euet lo ak pai New Zealand Medicaounal89: 22. uen Opinion Mod GM a Caim B (997) Rheumatologi maifetatio of maiga in Rheumaolo 9: 7579 Moi  ]. M. Lua D   B ele B  96 1) Role of he tuk i ab iit of the pie joual oone andjoin uge 43A 327-3 51 

Nomal and Inju y Mechanc o the Lumba Spne

 35

a of Nceson, AL, n Mois M 1964 n io eseens of iniscl pesse Bo ad ot S46A: 1077. Nceson, A 966 Te o on l iscs in iffeen posiions of e ody Ccal Oto padcs ad Rlatd Rsac45: 107. Nceson , A, Andesso n  B ]  n Sclz, AB  1 96 Vlsl  noe e ioec nics: f fcs on l nk os of elee n-oinl pesse Sp 1 1 5: 476 Non , Wels R Nenn P nk, P Snnon, H, nd Ke, M. 199 A copison of pek s cie pysicl ok expose isk fcos fo e epoin of lo ck pin in e ooie indsy Cca Bomcacs 13 56173 Noyes, F e cs, ]L nd oik P 994 Bioecncs of gen file An nyss of sine sensiiiy nd ecniss of fle in pies oual ofBo adot Su 56A: 236 Ne, P  9 Aeoic execse in e ee n nd peeni on of lo ck pin  Sat ft A R ofOccupatoal Mdc3 37 Ogno, S Rkno AS Noiko E Zsepin ST Rodono SS, nd Cnn C 99 Te se of n one isse ding spce fli Acta Astoomy 23: 129-33 Pecy, M Poek, ]. , n Sepe , ].  194 Te e iension x- y nlysis of no l esre  en in e l spine Sp 9 294 Pecy M  n  Tiel, S B  194 Axil o ion n lel ending in e no l l spine ese y eeiension diopy Sp 9: 52. Pillps, P  997 V il iis ut Opos  Rumatolo 337-344. Rnnen,  He, M, Flck, B, e l 1993 Te l lifids sce fi yes  se fo  l ineeel disc eniion Sp 1 6-74. Relly Tynel, A nd Top D  94 Cicd in  ion in n se  Colo Itatoa 1 121. Ricdson, . l, , Hodes P nd Hes ] (1999 Tepec execse fo spin seen silion in low ck pin. Edn, Scoln: Ccll iinsone Rof, R  1960 A sdy of e ecnics of spinl inj es. oua ofot ad Bo S42  0.

T

:

Ross K  eezni k, D   n Mcil, SM .   999 Als- xis f ce sye y: pl icions fo  n plpion p 24 2 1203-1209 Rossinol, M, Sock, S , Py , nd Asong, B  1997 Cp nnel syndoe: W is i le o wok? Te Monel sdy Occupatoa ad omta Mdc 4 9-3. R, S H , e Lc, C] Eley, M nd Bi js R ].C.  99 Spec l eec oyogpic  ssessen of ck scles in piens i o ck pin ndeoin eiion Sp 20: 3-4. Si, K Cssnoi e Fedeneic, ] lopin  Le Fo D, nd Slde H 996 Ace e cpl nne synoe ssoced i e  n pois  19 in fecion a f tos Dsass: A  ca Pulcao of  Ifctous DsassSocty fAmca22  62 64 Sngi P n Mcill SM (995 Te psos jo scle A ee iension ecnicl oellin sdy i espec o e spine sed on MR eseen oua ofBoa cs 2 339345. Scl , A  , Wic k  N  Bekson, MH  nd Nce son, A L 979 Mec ncl pop eies of n  spine oon seens P I: Response in flexion exension, e nin n osion ua ofBomcacal g 101: 46. Sidll, P, n Cosins , M  1 997 Spine pin ecniss  Sp 22: 9-104 Sionen, , Lindgen K Aiksnen, nd Mnninen, H ( 997 Moe en dis  nces of e l spine n nol ck scle eecoyopic findings in ecen ow k pin

,

0.

Sp 22: 29295. Snook  SH, Wese B.S  Mcoy , R. W, Fo len M . n McCnn K B 9 9 Te e cion of conic nonspeif ic low ck pin og e conol of e ly onin l  flexion Sp 23: 26012607 Spence, L, Mlle AA nd Sclz, A.B 19 Te effecs of ceoncleolysis on e e cnicl popeies of e cnne  disc. Sp 0: 5. Sokes, M  n on A (1 94 Te coniion of eflex iniiion  o oe nos scle wek ness Cca Scc 67 7-14. nk, N, An, HS., Li, T-H. Fji A, eon ., n Hgon M 2001 e lionsip eween isc degeneion nd fexiiliy of e  spine Sp  : 47-56 .

3 6

Low Back Disorders

h  M  u  .  ad va  .  187  he abdom ial muc l ad v rteba tability  pi 12 501 homo     188 O th e bdi mom et capability of th pu rizd abdo ial cavity duri huma lifti activity Egoomis 31 5: 81 roup  G  Marti W ad Lloyd  CE .  181  Back pai i  dut A propctive tud y ie, 6: 61-6 Vo-Robert B .  ad P rie C..  173 ea  trabecular micr ofractur i th bodi  of umba vrtebra as oe Remai Diseases 32 06-2 Vidma  umie M. ad oup G 0) Lumbar pia patholoy  cadaric atrial i reatio to hito of back pai occupatio ad phyical loadi pi 8: 728. White  AA . ad Pajabi M M. 78 iia biomeais e spie Philadlphia: B. Lippicott Wider G Pope M. ad rymoyer .W. 88) h biomechaic of lumar dc hiatio ad te effct of ovrload ad itabiity oa 0pia D0e 1 1: 16 Woo SY Gomez MA ad Akeo W.. 85 Mchaical bhavior of oft tiu Maur mt modifica tio ijurie a d teatmt.  ahum . M  ad Melvi  d  ioa i oama pp 1033) walk C: Appleto Cet Croft. Woolf Bett G ]  ohet y M ubr R Kidd B Koltzb ur M ipt o . or  .  aye R  a d orebjork E   18 o ward a mechaim-bad cla ificati o of pai ai 77 7- Yli R  ad McGl  SM  a Aterior hear of pial moto m t: iatic kt ic ad reulti ijurie oberved i porcie modl pie 2  18 1882- 88 Yili .R  ad McGi l S M.  b) Mechaical pr opei ad fai ure mch aic of h pi uder potrior hear load  Obvatio fr om a porcie modl oa pia iso 2 6: 008

(5):

15

..,

a

Lumbar pine tability: Myths and Realities S

tlty s a popar tr whn scssn th low ack  t ay  wly snrstoo an nappropraly s In prvos chaprs w stalsh svral rlvant facs Frst, all sorts of tss aa rslts n ont laty, whch n t can la o nstal For apl, stran or fal lants cas jont laxy

an nsal nr loa that Enplat wthjon losshavor of sc hht arjont an othr aploton of tss aa rslts fractrs n nstal Clary, nstalt s a consnc of tss aa hs s ncly sarz y Oxlan t a 991 A nanta tnt s hat lost chancal ntrty n any loadarn tss l rsl n stffnss losss an an ncras rsk of nstal havor W also saw n chaptr 5 hat rn an vn n whch nsal was osrv th ckn powr lrs spn nLY rslt So nstalty can oh cas an  h rslt of njL Fnaly, ovrlayn th tssas aspcts of stalt ar h otor contrl aspcts snc coorna contracon stffns th ons an ltaty trns jon staly h prpos of ths chaptr s o prov a fnton of saly an an nrstann of ho t s ncras or cras hs s a crtcal fonaton for hos prscrn stazaton rcs or rconn strats to prvnt nL  Atps to nhanc stalty an prvn nstalt ar copros wthot an nrstann of th nflncn factors o ant hos factors, howvr,  st ar on fntons What xact o w an whn w s th trs spne stty or stlty an stlzto xrs? Oftn hy pn on h ackron f th nval o th ochanst th prtan to a chanca srctr that an co nsal whn a "crtcal pont s rach a sron ay vw anoral jn moon pattrns as nsta t corrcta y changn th anaoy; an th ana cn practonr a ntrpr pattrns of scl coornaon an pos s ncatv of nstalt an attpt o altr on or a fw, scl acvaton prfs vra grops hav a conrtons to th staty ss, t onl a vry fw hav ttp to actally antfy stalt hs crtca ss s arss hr pon coplon of hs chaptr, yo wll nrstan stalt an ts porac n nry prvnon an rhataton Fthror, o ll nrsan why crtan approachs ar prfral for achvn sffcn staly 

13

Low Back Diorder

: A Qv A  folloin onstraon of srtal salty illsats ky sss Sppos a isin ro is pla pi an rial t t  on  n   ro  to a a sa oa pla in its ip, paps a pon or to i wol soon n an kl No sppos t sa  as y irs atta at frn s alon is lnt an tos irs ar also atta to t on in a irar pattrn s fr 61, a Ea y r s p o t sa tnsion ts is ita No if t tip of t ro s oa as for,  ro an sstain t oprssi fors ss sy  yo  r t tnsion n jst on  of t wrs, t rokl i l at a r loa  ol atally prit t no, o los o Coprs si oan siilar to tis as n pfo on an la spin s. ypially an ostoliantos lar spin fro a aar t sls ro an no y is il k n appoiaty 90  aot 0  of opss loa fist not y as an Bslr, 1961 is is al tat a spn an itsan! is analoy onstats t rita rol of t sls t gy wirs to irst nsr sffiin staility of t spn so tat it is prpar to witsan loang an sstain postrs an ont lso onstat it tis apl is t ro o  otor onrol syst, wi nss tat  tnsions in t als ar proporiona so as to not at a noa point r kln l or. Risiin t kin injry at w osr oosopially in  po litr pa 125 w wol ypotsiz tat it was as y a oor ontrol rror in wi possy on sl r its atiation o fo  pios analoy ost its siffnss.  synrony of alan stfnss po y t oor ontrl syst is asolly ritial. ow  an arss o staility is antfi an ola

F  The spine s analogous to a fsng rod placed upight with the butt on te ground. When compessve oad s appled downward to the tp, it w bucke quicky a Attachng guy wes at dierent eves and n dferent diectons and most impotant tensonng eac guy we to te same tenson wil ensure stablty even wth massve compressve oads b Note tat the guy wies need not have gh tenson foces but that the tensie foces must be of ougly equal magntude. his s the ole of the musculature n ensung suficent spine stabty

mbar Spne Stablity Myth and Realte

139

v    hs ston ntfs th noton of stlty ro  spn prsptv Drn th 1980s, rofssor Anrs Brrk o Swn vry lgntly forlz stty n  spn ol th jont stffnss n 40 sls Brgrk 98 n ths ss work h s l to rprsnt thtlly th onpts of "nrgy ws stffnss stlty, n nstlty For th ost prt ths snl work wnt nrognz lrgly s th ngnrs who nrstoo th hns  not hv th olo/ln rsptv n th lnns wr hnr n th ntrprtton n pltons of th nnr ng hns hs ston synthszs Brgrks ponrng fort n ts ontn volton n th work o svrl othrs n ttpts to npst th rtl notons wthot mthtl opty f yo r thtlly nln, s rrks orgnl work or ts orlzton y Cholwk n MGl 996).

Potential Energy as a Function of Height h onpt of stty gns wth potntl nry, whh for or prposs hr s of two s fors In th frst for, ojts hv potntl nry E y vrt o thr hht ov  t. E

=

ss grvty hht

Crtl to srn stlty r th notons of nrgy wls n nmm otn t nry A l n  owl s onsr stl s   or or  prtrton wr ppl to t, t ol rs p th s of th o t thn o to rst n n th poston of lst potnt nry t th otto of th owl th nry wl s fgr 6.  As not y Brgrk, "stl l r prvs whn th potnt nry of th syst s n h syst s m or stl y pnng th ol n/or y nrsng th stpnss of th ss of th owl s fgr 6.3) hs th noton o stlty nopsss



F  The conum of ably.he eepe bow a  mo abe an he hump d  ea abehe bal  he bow eek he eegy wel or poon of mnmum poea eegy m· g h. Deepeng he bowl or ncea g he eepne o he e creae he aby o urvve peurbao h ceae ably



m* * h

lo p 



Wh



jnt f j xt

F  The eepe of he e of he bow coepo o he fne o he pave ue of he jo, whch ceae he mechacal op o moo he wh of he boom o he bowl corepon o jon axy Fo exampe, a pove "awe e" o he kee woul be repeene by a flaee boom o he cve  whch ma apple foce pouce arge unoppoe moo

10

Low Back Doder

the unperturbed energ tae of a te and a ud of the e follon pertr atonf he oue of work done  the peruration are le than the joue of poential ener nherent to the te, then the te i reain able .e the bal il not rol out of the bo) The corolar i that the echania te wl beoe untale and pob ollape f he apped load exceed a rita vaue (deterined b potentia energ and tffne) he prevou al analo  a todienonal exaple h would be analogou to a hned keleta joint that ha he capact onl for fexon/extenon Spina jont can rtate n three plane and tranate along three axe requrn a ixdenona ol for each joint Matheatc enale u to exane a 36dieniona ow 6 lbar joint wh 6 deree of freedo each repreenting the whoe lur pne If the hegh of he bol ere decreaed n an one of hee 36 denion the al oud rol out In lnca ter a ne ue havn an napproprate fore and thu tiffne or a daaed pave ue hat ha lot tiffne can caue ntai tha  oth predcabe and quantfiale Se clnican have confued pine tal wth he bod ance and ab, whch nvolve he cener of a and ae of upport n he conext of fang over; th  qute derent fro pine ait. Fure 6.4 a and  llutrate he echanic of hoe bod baance and tabit Fgu 65 a and  ho the nal practce of proddin patent hi approach i guided fr enhanng pine talt



 

F  Anoer ype o sabiliy oe confsed wi spine com sabliy ivolves e ceer of mass ad base o suppor in he conex of fallig over he rage i a s sabe becase a small perrbaio o s op would o case  o aTe sze o is sabliy ca be qanied i par by e sze of he age ea: as he cener o he mass approaches a verca line drawn from he base of suppor i woud reqire a smaller perrbing force o fal demo sraing a  s sable b ess so b

Lmbar Spine Stablty Myth and Realte

1 1

F  Mindedn biy ired  he exmpe iven i ie   led clincn  ry  ehnce pine biy by pddn pie d empin  kck hem  blnce a nd b T  n pine bliy b whe bdy biy.

Potential Energy as a Function of Stifness and Elastic Energy Storage Wil ponta nrg b  o it i  for ltrating  onp pon ia nrg a a fnton of iffn toag of lai nrg i ro atal  for lokla appiation. Eati an potnial nrg i alla tfn k an oration x in t ati lnt a own r PE





/* k* x

: < tl >: b

=

/2  





W ill  an lati ban a an xapl Strting t ban it a tifn  a  tan x it will tor nrg (PE T trt an a t potntial to o or n trt In otr or t gratr t tiffn , t gratr t tpn of t i of t bol (fro  prio analog an  or tabl t ttr. T tfn rat abili ( fgr 66 Mor pifial tri tiffn rat

F  Incei he fne  e cbe (mcle) ncree he bliy (r deepe he bw) nd cree he biy  ppr er pped d (P) wih in. B m imprn, erin  e ie  bnced  ec de enble he clmn  rvve perbi rm eie de cre ine   ne pin wil clly decree he biiy  ber cmpreive d (lwein PE n ne dreci nd mde) lrn e eed  "bnc" ie   ven pre d mme demnd •

142

Low Back Disordes

F  a Spine stiness nd stbity s ceved by  compex itectio of stffeng structues og te spe nd b those ormg the toso w Bcing stiffess o l sdes of the spie is more critic to ensuig stbilty th vg ig orces on  sge sde

L

even re staility. (Syety in stiness is acheve y virtally al scles f the trs see fir e 7 a.) If re jles f rk are perre n the spne than jles f ptentia enery e t stiff ness the spine wll ece nstale (see fire 

Acte scle acts like a stiff sprin an n fact the reater the actiatin f the scle the greater this stiffness Hffer an Anreassen (9) she that jint stiffness ncreases rapy an nnlinearly with scle actiatin sch that nly very est levels f scle actvity create sffcienty stiff a stale ints. Frtherre jnts pssess inherent jint stiffness as the passie capses an laents cntrite stffness particlarly at the en rane f tin The tr cntr syste is ale t cntrl staity f the jnts thrh crinate scle cactivatn an t a lesser eree y plac in ints in psitins that late passive sti ness cntritin Hwever a falty tr cn trl syste can ea t inapprpriate anites f scle frce an stiffness allwn a valley fr the al t rl t r cinicay fr a jint t ucke r uner shear translatin Hweer e are l ite in r aility t analye the lca staiity f F  f more joues o wok e peformed o the echanical systes an particlarly sclspe th joues o potet eergy due to stffness, the spe wl become unstbe-in tis cse, te stbity skeleta inkaes since the enery wells are nt mode is buckg infnitey eep an the any anatica cp nents cntrite frce an stiffness in synchrny t create srfaces f ptential enery in which any lcal ells exist. hs e lcate cal inia y exainin the eriate f the enery srface (See ergark 197 Chewiki an McGill 199, fr atheatical etail)

Lumba Spine Staby: Myhs and Reales

143

pne sablt, then s qantfed b frmng a matr n whch th tta "stffnss ener fr each degree of freedom f jnt mn s represntd  a nmbr r eigenvalue), and the mantde of that mber rpresens ts cntrbtn t f\ng the heht of the bwl n tha partclar dmensn. Egenvaes les tha er ndcate the ptenal fr nsat The eigenvector dfferent from he genval) can thn dent the mode n hch the nstalt ccrred hle senstvt aalss  sd t reva the pssbe contrbors to nstabl behavr GardnerMrs and clag 995 taed nterestn nvesatns n egenvectors  predtng atrns f spe defrman de to mpard msclar ntersemntal cnr Thr qsn was Whch msclar pater wod have reventd the nabl Crsc and Panja 992 bga nvestgatons nto the cntrbtns of he vars asv ts Or grp ha ben nvestgatn he eenvectr b ssematcall adjtg th ffnes of each mscle and assessn stabt n a varet f tasks and exercs Th cnrb tns of ndvdal mscs t stalt ar hn atr n ths chater Actvang a grp of msclesynergists and antagonists n th tmal a n becmes a crtcal sse In cncal trm, the fll complemen f he tablZng mlate mt rk harmonosl t esre stabt, eeratn f th rqrd mment and dsrd jt movement t o one msce wth narrat actvatn amplde ma rdce nstabl, or at ast nstabe ehavr cd reslt frm napprprae acvatn at lower appld lads

Sufficient Stability How mch tabl s necessa Obv, nsffent stffns rdr th jt nstable, b t mch stffness and actvan mposes massv ad nat  he jos and prevents moton. We a defne ffcent sablt a h mclar tffnss ncessa for sat wth a mdest amont f tra stablt t frm a margn of saft nterstnl, ven he rad nrase n ont stffnes h mdes mscle force, large msclar frcs ar rarl rqrd. Chleck's rk Cholewck and McGll 996 Choleck Smn, and Radebold, 2000 dmns trated hat  mst epl w th an ndev ated n, mdest vels f cacvaton of the parasnal and abdomnal wall m ll relt  sffcent stablt f th lar sne Th means that peol, frm atnts o athltes ms b abl t mantan sffct stablt n all actveth  bt ntn mcle actvatn Ths, mantanng a stalt margn f aft hen performng tasks, partcarl the task f da lvn s not comprmd  nsffct strength bt proal  nsffcent ndrance. We are n begng  derstand the mechanstc pathwa f th stdes showng the ffca f e dance tranng fr th msles that stable the spne. Havng srng abdmnals does no necesarl prde the prophlactc ffct hat man hd fr. Hever, several rks gst that mscar ndranc redces he rsk f ftr bak trbes rngSrensen, 1984. Fnall he Qeensland r g., chardn t a 999 and everal others e.g., OSlvan, Tome, and Al, 99 td th Ths dstrbance n the motor contrlh stem fllng jsffct dtaldtabl  chatr 5). drbances compromse abl to mana  mmar, tablt cmes from stffnss assve stffess s s wh t damag and actve stffns throhot th range f mon s lst wth ertrbd mtr atterns folwng nj.

 M, ,  C Imp Havn elrd me of the ss f n tablt, we wll n cndr a f crcal qtns that ll help enhanc lna decsos.

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Low Bak Dsorders

• How much muscle activation is needed to ensure suffcient stability? Te amount o muscle actvation needed to ensure sucient stabit depends on te tak Generall, or most tasks o dail iving, ver modet eve o abdmina a cocontraction (actvation o aout 10% o MVC or even less) are suicient. Agan, depending on te tak, cocontraction t te extensors tis ill aso ncude te quadratus) ill ensure stabiit Hoever,  a joint as lost stines because o dam age, more cocontraction s needed A specic example s sn n capter 13. • Is any single muscle most important? everal cnical roups ave uggested cusin on one or to muscles t enance stablt. Tis ould be imlar to em pasng a inge gu re in te ising rod example. Rarel ud it elp but rater ould be detrmenta or acieving te aance in stiness needed to enure tabilt trouout te cangn task demands. n partcular, cnica rups ave empasied te mutiidus and transverse adminis Te Queenand grup perormed some o te srcina work empasng tese to mucles. Ts a based n teir researc, c noted motor dsturance in tee mucles llin inur n act, te developed a tissue damage mode tat suested tat croncal por motor control (and moton patterns nitiates mcrotrauma n tissues tat accumu ates, leadng to smptomatc nur (Ricardsn et a., 1999) Furter accrdin t te Queensland mode, injur eads to urter deleterious cange in motr patterns uc tat croncity can on e broken it pecc tecniques t reeducate te lcal muclemotor control stem. Te ntentions o te Queensland roup ere to addre te dcumented motor deicits and attempt t reduce te risk o aberrant mtor patterns tat could ead t te patooginducin pattern n ter damae mode n oter wrd, teir recommendations appear to be drected toard reeducating te ault mtr pattern. Hever, man cnical roup ave inter preted t apprac to mean tat tee o muscle sud be te pecc tarets en teac n stabilit maintenance over all orts  task. Hopeul te undertandin b

taned rom te stabilit explanation provded earlier ill underscor te l o tis unidmeniona empasi n act te multdus or an otr muce can be te most important tabier at an ntance in time Te tranvere adomni en quantied or ts inluence n stablity, acts te same a Fur exerces are n a an example (see gure 69 ere te contrtor to stablit are sn. u uld realie tat te il cane and adjust it subtle cange n relatve mucle activation. In tese example entire musces are adusted to evaluate tr rle Ob viul, adjutments in sinle amnae o om musce would reult in t a dierent ditrutin o contriutions t talit Evaluatng a ide variet o task and exercie s mst revealin.Te mucular and mtor contrl tem mut ati requremnts to ustan potures, create mvements, brace aanst sudden mtion r unexpected ces, buld pressure, and assist callened reatin, al te le ensung ucient taily. Virtual al muscle pla a roe in enurn tablit ut ter mportance at an pont n time is determined b te unique combnatn  t demands just lsted. • Do ocaVgobal or intrinsic/extrinsic stabers exist? rom te caic d

ntion and stabit, te aner oud beTe n Stabiit resut rm te tne at quanticatn eac joint in aoparicular degree o reedom. reative cntrbutn rm eveY musce urce is dnamicall caning dependng on its need to cntract r ter purpoe. Te a te varius cntributrs t tne add up ever  mportant. n me nstance, remving a muscle rom te anais a ve tte eect n ont talt. Once aain, it depends n te demands and contraint unique t te tak at tat nstant Te point is tat all contributor are imprtant r me tak and suld be recognied a potentall mportant in an preventin r reabiltatn

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Brd dog wit arm and leg lift

F 9 Measrig dvdal musle uee o lmbar spe stablity while perormig for dere stabliza tio" exerses demostrates ha all muses are mporat ad ha ther relative importae hages wth he task Toa sabity s aso diaed by the determat demosratig how sabty a hage bewee tasks Ths s a example from a sge subetypiay, grop meas date a diere stablty rakig o exerises Courtesy of N Kavi and SMGil

progr Conversly oneivin tbiizrs s intrinic or "xrinsic y or no nit or inicl deision king • Whatin are stabilzatio xrcis n  e stblec cor iscssd exercis orsexercises? W re Stiity siiztion exercis? i r ttotn ny xri n be  tbiliztion exrci dpnin on ow it i pror Siint join sinss is civ by creing spcifi oor ptern o pt  pr poplr in otor control cires, Prcti dos no k prt; it kes prnent. dely, good stilizion exris t re prored propery roov otor n otion ptrns t nr stbiliy wie stisying ll otr dend. s, n exri, rpeted in  wy tt grooves otor ptterns n nres  tb pine ontitts  stbilizion xercis MGill, 2 owevr, o stbilizion xriss r bter tn or gin, it epens on te ojectivs For xp t rltn lod on  pin is rrly onsidere On ky to iprving bd bk i to slt tbiliztion xrises tt ipoe te lot od on t dg spin Cp tr 5 provids  rnking o  xeriss On  oer nd t st tbilition exeris or  igprorn ee wil invov e groovin o  yni n oplx otion pt, ll te wi nsuring sicient pin tbility An ipornt rirnt or ny tlte i to nsr  stbl pin wi brting r   wn pying igintnsity spors. is will  issed in ptr 4 • Ca cliicias idet those who are poor stablzers? From  ittiv perpetiv te Qnnd grop observed brrn otor ptts tt ty y poizd o coproise te biliy o e d person to biliz iintly. Fro  ntittiv prspeciv w ve sed odling nlyi to ry o in y to idntiy to wo omproi teir lbr tbility rom pii tor ontrol rrors W obsrved  inpproprite sl sencing in n o r  eng by oing  lod in te nd wil brting % CO  to lvt brting On on nd te sls st coontrct to nre sicint pin stbiity, bt on

146

Low Back sordrs

t tr, callenge reatng  tn caractrz y a ytmc cnrtn/elx atn f te amnal wall (McGll, Sarratt, an Seun, 99 u, t mt systm  prsnt wt a cnct: Sul t t muc man actv mtr caly t mantan ne stalty, r wl tey rytmcaly ra an cntract t at t actve expatn ut acrfc pne stalty? t mtr ystms  t mt te multaneus ratn an n upp calen unft ns my nt Al f te fcent mtr cnt mcansms wll gten mecanca uctlty t nury r rnjury Clewck an McGl, 199 W ar curently unt pgm n  lntunal tuy t e f te  rr n ntaty ung t cnge wl  t ne w vp l ack trule me tr tt t tet functnal ntaty ar esc n capter 12 n ummay, acvn stty  nt jut a matter  actvatn   target mucl,  ty te multfus, tranvere amn,  any ter ufcent taty s a mvn tagt tt cntnually can a  unctn f t tremnnal trqu need t uprt ture It nvlve acevng t tn n t nu unpct la, prarng fr mvng quckly, an ensurng uffcnt stffn n any e  freem  t jnt tat may  cmrm fm njU. Mt cntr ftn  essntal fr acvng te talty target un  s cntn fr prrmanc an nj avanc

R Brgak, A. 1987) Mechanial stabiy of th huan uba spin Doctoral dissao pat nt of Soid chanics und Univrsiy Swn Bring-ornsn F 194) Physca asurns as ris nicators fo ow ba rob ov a on yar pro Spine 9: 10619 Choeic J an McGi  (996) chanica stbiity of h i vvo ubar spin Ipcations for inj an chronic lo ba pai Cliical Biomecbaics, 1 ) -5. Choic J Sons AP, an Rabo A 2000) Effcts of xal tun oas o umbar spn stabity joual Q/Biocbaics 33 1): 1385 Cisco JJ an Panjabi M 1992) Eu sability of th huan ganous lbar spn Pa I: Tho an Part : Exprmnt Cliical Bioecbaics : 2-2 Garnr-Mos  Stoks A an Laib, JP (995 Rol of h uss i ubar spin sabily n ax xnson fforts joral /O1bopadic Rearcb  82-8 Hoffr  an nrassn S 9) Rgation of solus sle siffnss n p<laY cats jal Q/Nepbyiolog 45: 2625 ucas D an rslr B (96) Stabilty of th lgantos spin n: Tch por No 40, io chancs aborato nivsity of Caifonia an Fancisco cG M 20 nvt rvw o back stabil: Fro foral dscpio  issus fo prfo anc and habiation ercis a Spors Scnce eview 29 ) 26-3 McG M Sharat  an Sgn JP 199) oas on th spinal tisss rng siultanos fting an vntiato chaln Erooics 3 9): 12-192 O'Sivan P Twoy  an Allson GT 99) Atr pat of abona us ataion i chroni bac pan patnts. Austlia joal /Pbiob  91-98 Oxlan  Panjabi MM outh EP an uranca J 99) An anaoc bass for spna nstabiity: A orcin taa odl al obopac Rsarcb. 9 452-462 Rchason c., Ju G Hos P an Hs J 999) Thraputic xrcis for spna sgnt stabiization in o bac pain Enbrgh oan Chchi vingston

Injury Prevention

n part I we went back to school for an update on lumbar function. In part II this foundation is used to justiy the best injury prevention approaches

I

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Risk Assessment LBO

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w ps  psca s acts psps ppl  vlpg  bac uls: s li t t ps  xapl uscl uac   lac  ad s l  t as  pig a ctai as  xaml ap pl lads s cat scis w t assss t is  bac tus tat sult   as as p cpi  s cap u will udsta t vaals a a ip at  icu  is assss ad  ailia wit t ts t assss t is s tls clu t NIOS appac  S pscpsical aac  uba t t LMM) appac ad  40 WABAK appac ssu vad causs aag a susut w ac uls Assssig  is ivlvs cpag appli las wit s   abaig ac valu Cap 4 clu xaps  appli as tissu lads ad iju scas Altu ct asut  tssu las wul b ia ts ais actcal  la ubs  ppl pig a wi vat  ccupatial tss a actvis  al livi Rsacs av vp vaius mdig appacs t pdic s las but t a lgical cpx F is as su gas  tssu la tat a l wit pst, appli la ad ti av b ppsd s w ituc i cap 3 Epidigca Studis   ac Disds BDs S B Rviw  t Rs Facs  B ag 0  a list   is acts at als dscibs ad cius sva appacs  assssig t Fu is asssst appacs a pstd   ss  as cx t st cplx  slst appacs us ics at a t asst ad cas t pl  ijur is asssst wv ts a cpis b a ac  accuac a spcicit a a  sstiv t iivua /ps cu   cplx apacs ivlv  spsticat tds ad a m xpsv t cduct but  a m ust  ti ssiiv  spcic ass ad t dvidual was i ic ppl lc  p 

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Low Back Disorders

Brief Review of the Rsk Factors fo LBO

Risk Factors Identied From Epidemiological Approaches  Si k psus spil pgd uk flxi d  isd  ll b k psu 2. Sd kg psus 3. u s i high spi il vi d si l dvis . u lifig pushig d pullg 5. Vibi xpsu piul sd hld vi 6. k d uuliv l k sh f pssiv  d xs  . id f slps d flls

Risk Factors Identied From Tssue-Based Studies . Rpd ful lub x 9. i  d  i  isi f bd) 10. Exssv giud d pii f pssiv lds sh lds d tsl dsp d s 11. sufi dig s h issu sgh s pisd 12 Rpid llisi ldig suh s sus duig di   fl

Personal Variables Identied As Risk Factors 13. Isd spi li  f ) 14. L s us du 15. ubd  l ps 16. Ag 17. Gd 1. Abdl/s gih

NIOSH Approach to Risk Assessment  bu h ps 0 s h fld sil d lr sudis hv fusd  h liship w k iju d pssiv fs xpid  h lub spi  xpl i 191 h Nil Isiu f Sf d lh NIOS) pulishd uidlis f xiu pssiv ldg f h lub sp h  i lii  300 N [ut 750 b] d  xiu piib lii f 6300 N [bu 1400 b]) bsd  s l vid  199  usid h us f  pssi h h ui l sd h h suppig vid f ssi s  i  idx f isk ws sps wv si h i svl d d ss hv sh h siig h u f l bk pssi bh  d uu liv) is  vlid pph  duig h isk f lw  iju f xpl d ss i h viusl disussd N   99 sud d h rs   1995, sud) I ddii NIOS hs ls ppsd lifig guidis  lii h u f ld lid i h hds hs liis  dsibd i h flli ss

BD Rsk Assessment

151

Th infn o NIOSH has n far rahng many gros hav sd ths as n an attmpt to rd th rsk in orkrs n at th NOSH approah ontns to b idy sd today rimary bas of ts as of s

98 Guideline Th frst tin d (NIOSH 981) as rstritd to fts n th saitta pan and ifts that nvovd ony sow and sooth motons. Prdtions of th oad ftd n th hands as basd on so rdmnta dstans to haratrz th kinmats o th t and oad mont at th ow bak To ts r dind th ation iit AL) whh f xdd trggrd ation to apy nnrin and ans tratv ontros, and th ax prss t (MPL) or th oad td, abov whih th risk s too hh and not prmss Wghts ightr than th A ar onsdrd saf. Exrts wth bomhania, physooga, and syhohysa xrts hos th agntd o ths mts and th varabs ndd to ot th. Th gnra orm o th ora sd to opt th AL or ght in th hands s as oos AL (k



40 (HF) (VF) (D F) FF)

whr HF horzonta fator, or th horzonta dstan H) ro a ont bstin th anks to th ntr of graty o th oad at th t orgn. Ths as dind as 15/H. 

V vrtia ator, or th hht (V) o th oad at t orin Ths as dfind as (0004)/(V-75) 

F



dstan fator or th vrtia trav dstan (D) o th oad This as

dfnd as . + .5/D F frny fator or th fting rat din d as 1  F/Fmax 

F



avra frny o th it hi ax s otaind fro tabatd data

Th ogi o th qation is to st a maxima oad o 40 k (88 ) and tiy ths va aainst arabs that at as disont fators Ths th maxia ft s 40 k 88  ndr optma onditons and hn a dsont variabs qa nity . Sbop tma ifting onditons as th disont tprs to dro to smar vas, rd ng th sa oad. Th PL s omptd as thr tis th AL for a artar st of ftn rstas: MPL



3(AL)

993 Guideline Th risd IOSH aton (atrs t a. 1993 as introdd to addrss thos itn tasks that ioatd th sagttay symtri ting task rstriton of th arr qation In addition, th ont of th AL and MP wr rpad with a ro mndd wiht mit (RWL for a partiar situation. If th ata oad to b ft ds th RL th risk of dvong an LBD s vatd h th RWL ation is smar to th 198 qaton to additiona fators wr norporatd. Ths n  an asymtr varab or nonsagitta ts and a ator for whthr or not th

52

ow Bak Dsordes

bect hs hndes. Nte tht the specic ve weghtins hve s chned m the 98 etin m WL (kg



23 25/) [  (0003  V  75 1 )] [82

+

4. 5/D (FM [  (00032A)] (C

here  hriznt ctin d  the midpint etwee the kes t the riin  the it  sigiicnt ctr is reed t the destntin, the H shd  mesed th t the rigin nd destintin  the it 

V



vec ctin t the rign  the 



D vertic trve dstnce between the gi nd destintin  the it FM reency mtipier is tined rm  te sppied y NIOH 

A nge etwee the mdpint  the nkes nd the midpnt beteen the hnds t the rigi  the it =

CM cping mtipier rnked s eithe gd, r  p It is btie rm  tbe 

The 1993 etin predicts smer ds tht cn e ited sy hen cpred t the 98 etin, nd is ths mre csertve Interestiny, OS eed  prvisi  the dierence cpcities  men nd men; they re treted imiy r rey pitc resns ( discssed this isse  discrimintin d the impt  prtectin vnere rkers in chpter 1.) Fther the pprch ired y idi vid dierences in dy mechnics sed whie iting  dditi, sme hve s ested tht the hnde ctrs my nt e cnsistent with the sbseet rces e dre by the bdy Fr empe, whie NIOS ssmed tht hvin hndes  the ited ject is etter, r wrk hs shw tht hndes  the iter t ppy even mre rce, restig in sseenty higher ck ds (ns et  1998! Nnethe ess, the etins rm  rdimentY pprch t risk ssessmet tht s esy t cndct. Mrrs nd ceges 999 ccded tht the 981 NIOS ide idetiied w-risk js we (speciicity  91% t did t predict the hhrisk j bs we The 1993 gide crrecty identiied 73%  the highrisk jbs bt did nt detiy the w d medim-risk jbs we Over, th NOS gides predicted thse jbs resti n D ith dds rtis between 31 d 46 Mrrs d cees 999 nted tht the mst pwer individ vribe ws verge w ck mment d i hs nd the hrznt distnce etween the nteriry pced d rm the spi

Snook Psychophysical Approach he psychphysc pprch t setting d, r rk imts, is se n pepes' peceptns s t ht they ee is  terbe wrk rte. The mi citicism  this pprch is tht mst pepe perceive physiicy reted discmrt n nt the ten tisses tht cty dme Frisempe, D, Des nd mittdn 994) n mde  cse tht mscecses discmt hich ediy perceived my nt e crreted with ct tisse ds Wrkers my nt be cgiznt  the tisse ds s they rech dmging eves (McGi 1997) Frthermre, Krsk n cees (Krsk d Pnptsegs, 1989; Kwski, 99 99 ted in  seies  stdies tht the geer psychphysic ppch is very dependent  sch ctrs s the instctis prvded t the periment sbjects d the cr  the ject beg ited t me  cpe Fr mpe the nk stdies 978 dvised the wrkers t dtemine  wrk rte d d t e mved bsed n the

LBO Rsk Assessment

 53

inrucion of no o com undl fgd Th workr cd h lod h rcivd no o  figing.  whn Krwowki rpd h xrimn bu chngd h inrcion o lf lod o h h would no com injrd h c c lod chngd h cho mllr lod Krwowki nd Pongnug 989) whn vuing h ffc of h coor of h ox ng lifd nod h workr woud if mor whn h ox wr whi,  h prcivd h blck box  bing mor dn Th pchophicl pproch ppr o dpnd on mn fcor h modl prcion. Th work of nook nook 978; nook nd Cirillo 199) i robb h mo rcognid in h pchophc r Th xprimnll conrolld vribl uch  obc iz high of h lif, nd movmn dinc n lifing nd puhing nd pulling k for oh mn nd womn Th conrcd  compiling h ccp bl od for oh mn nd womn ovr  vri of k On on hnd hi  proch inhrn incoror h dnmic of h k whi on h ohr hnd, h concrn rid in h prvio prgrph r worh conidring onhl, h nook pproch rmin popur for i  of implmnion nd c i i on of h fw mn mhod for phing nd pulling k

Lumbar Motion Monitor (LMM)

Figure 7.' Wearing the lumbar moto motor to ecord the tree-dmesoa kinematcs of te umar spine whie peorm ing ndustra tass. Poto coutesy o my good fied Proessor Bil Maas

vrl ud hv documnd h link bwn in moion nd h dvlomn of LBD  non mor horoughl hn ho of Mrr nd colgu 193 995 Th dvlopd vr p of rgrion mod  h dmonrd h pin moion nd in r lr, h voci of moion nd h rng of moion r morn prdicor of ho jo wih high r of dordr in fc om odd rio xcdd 0) Th lumr moion monior i  hr-dmniol goiom r h m h hr-dimnionl kinmi of h umr pin  figr 71) Mrr nd collgu howd h h kinmic vril oind from work r whil wring h MM , whn comnd wih iml murmn of lif frunc or moion d ccl nd od momn h lod mgniud mullid b h dinc o h low bck, provid imriv rik prdicon Uing h MM on op whi h r prforming r on k nd no loro mock p i rivl  o do In ddiion, h MM cp r h individu w in which popl u nd mov hr pn.  chpr 5 for  dcuion of h mch nim of inj h r dpndn on n our nd moion.

4DWATBAK Biomchnic modl hv n ud o im lod in h ow ck iu nd dnif highrik o for pproximl hr dcd. om modl wr inndd   impl ool for hlh nd f pronn o provid n pproxim ndx of nj rk on h pln foor Ohr mod wr dignd o b mor robu in luring injur mchnim nd ing niiv o workr vrinc Dciion  o hich modl o u o down o h prpo nd ncr complxi of h modl

'54

ow Bk Disorders

The eer "imle mde need he "cmlex mde  ase the many imiyin assumin ha aec accacy and validity  uu hich in urn deend n h ye  aicain Furher in many race he mt blaant r ve ernmic inj ri have een addreed and nly he mre ue risk remain Ernmist need ime mdel but al mu e cnversan ih he mre cmex mdel hat i asi in rectiin he mre ube inju rik and ais n deveing mre eective inevenin rategie Alhugh imle bimechanicay ased mdes  bain quic esimae   back cmressin exi rik assesmen r m  reuire me cmex meric and anaysi araches n an ert  imize iideliy and induria uiiy b Nrman Mady Frazer Rich Wel and I develed he tae acae 4D WATBAK The "4D crrends  he 3D mmens cmuted a jint hie rker errm 3D es/a u he urh dimenin  ime and he eec  reetiin n deerminin he ae lad ( i avaiae y cnactin rer Fraze) The acka use he deailed uut  he virua ine (decried in chaer 2 a a undatin bu make asumin  simliy daa clecin and t aciiae ruine anayi n his ay individual ker behavir and ine mechanic are quaniied but simi ed int averae muscular resnes een in rker ermin similar asks Thi realy imiie daa clecin and reserve he benes  eter anamica rere entain and mre valid edicin  l ac ad Furherme y incrat in the injury daa bained rm amle  rer 4D WATBAK uantiies the risk  ac injury drin uly heedimeninal a and ure The urth dimen in i me in h case a varale needed  ae n accun the reetiin  task ver a rk shi When uin the 4D WATBAK the jin crdinae daa i enered manually r the user maniuaes an n-screen manneuin n he rk ure  inerest The st are execute he dicul ak  deerminn he threedimenina jin mments by cmuin the Euler anle and tranrming hem in mmen abut he rhedic axes  each jint In hi ay he ackae i caale  calcuain jin ads in any ure and r any cminain  li ler uh r ul ta  as incrrates arithms tha catue he average muscuar resne meaured m rkers  sur hee-dimeninal sine mmens  rce gether ih srenh daa r h men and men As el he mdel i enive t ine ure in ha lamen and aive issue rces are invked durin uly exed inal ures Thu he mde mre accuraely redic l back hear ces ured by he ine (as cmared  reacin shea rce  her mdels) eher ih cmresin rce hat reut rm he lad and he many rs muscle cnacing  sur a articuar set  hreedimeninal mmens (see igure 2 a-) Finally the rik is al calulated rm accumulaed lads ding reeiive r y cmarin he ladime ineras ith eidemilic data ained rm a lare eillance sudy cnducted in an autm ive aemly an (Nrman et a 998 (See iure 3 ad)

Euler Angles and Orthopedic Moments simain  hreedimeninal jin mmen ae yicay errmed usin hee rhgna axe XZ B a a en mves the hedic axe  he ins ( examle in he umbar ine axis exin/extenin axis 2aea end axis 3axia wis als mve  tha hey n lne aign ith the ineial XZ axe The dieence beween he rhedic jint axes

BO Rsk Assessment

5 5

ad  XZ ax  drd w lr agl T pd mm a  ad fm  v appra drd  d ad Sa 983 T vlv ag  r-pd f  lg ax  prma ax, all w f w adja gm  f  da ax ( a flx/x T rprd f  prmay ad dar ax frm  -vr, w   m  rd  pd ax (al lara d Mm mpd a ax XZ a w  ra frmd  pf pd ax T  r a  j ax v a w  j a  pr mv w  ra rda m T 4D WABAK appra rpr a mprm w mpl mdl a ar a  mplm  a  vry r  r r am ad m mlx appa 4D WATBAK  l avl a  , ad  pvd m dg f v   wa dvdal wr prfm mplx a I  may r dx  qafy  q r frm a pf a prfmd v a wr f

9



 

8 c 0



'

( Q

Q E

6



0







 

 

x

Al , x = FE Y 

 

y =

w

Al  x  F/, Y  bnd 

F   WATBAK opus uba opssv load o an algoih psnng h avag spons o h any uss asud o a woks ha obn o suppo h nni obnaions o h low bak ons: xonxnson aal bnd and axa ws. Baus only h dnsons an b gaphd a on  a shows h sua o luba opssion o obinaons o xonxnson and ws ons whl b shows h sua o opsson o xonxnson and laa bnd

56

Lw Back Dsdes

 bk p ptg x Combied

0.2 7 0.51

Peak had oad (T g : T : A ) Peak L4-LS momet (T g  T  A ) Peak L4LS ompressio (T g  T  A ) Peak L4L5 reatio shear T g  T  A ) Cumuaive L4LS momet Cumaive L4L5 omressio 000

 b p pg x Comined Peak hand load T g  T  A ) Peak L4-L5 momet T g  T : A ) Peak L45 ompression U) Peak 4L5 reation shear T g  T  A )

c

0.47

0.21 013

Cumuative L4L5 reaio shear 

053 0.52

Cumuative L4L5 moment Cumuative L4L5 ompression Cmlative 4-L5 reation shear 000

0.24 0.50 025

0.7 5

100



0.20

0.23 0.23 0.22

021 013 024 050 0.25

0.75

00



F  D WABAK computes te jont-specfic three-dmensiona orthopedic moments at eac joint and uses several metrics to calcuate rs or exampe te low ac risk includes compresson and sear load tresod values aong with accumulated oads durng repettve wor y comparing the oadtme ntegras wit epdemioogic data otaned from a large survelance studywo exampes are showna reaching if a and b, and an overead assemly tas () and (d).

Biological Signal-Driven Model Approaches T a aroa for ik amt  o maur iooia na from a u in a attm o au  ndvidua a o form tir job ad tn u otiatd aatomia bomaia ad iooia rationi  a o to  vaou tu

The Marras Model and the McGill Model  Mara mod Mara ad ommri 199a 199 maur EMG rom v a mu ad ui kno oogia ratoni a for to t mu dui vtua an induria tak. A od air, i aroa rvad orfu vid ikng t a dmad of fi ouatioa ak it t ni d of LBD. T MGi mod MG 992 MGi and oma 96 ) u t am io oia aroa t ag for to t mu ut atm o iud t t v o anatoma aura oib Ti mod a inrodud in atr 2.) For

BD Rsk Assessment

 57

exaple,  alo eare ree-deoal pe vare o ae fore o e varo pave e, dg  erverral d ad e varo lgae. By agg fore o le ad pave e rogo e fl rage of e oo,  apre e dffere wa people perfor er jo ad eve ow ey age w repeo of e ae jo e ovo aly of e approa   eoro opaoa reqree, poproeg of daa, ad dffly of o leg  opreeve daa fro a wde er of worer  e fed Te qeo of e valdy of  pe of odel  e addreed aog w oer odel aed o e ologal approa Soe ave arged a e e ode oa ow oeaa ad pyologal reaop, ey oa a era ao of oe valdy Moreover, o e Marra odel ad e MG odel ave ee qe efl  eag e varo pave  ad l fore a  ogeer o rode exo ad exeo, laera ed, ad axa wg oe Tee oe ave ee we preded w e exepo of e wg oe.  ary, f wg  o a doa oe of force  a parar o, ee odel appear o e predg arae dro of fore aog e ppor e.

EMG-Assisted Optimization erap e rre pale of ode evolo  a yrd odelg approa ow a MGaed opao developed y Coew ad MGl 994  ab y aay ad e oad predo Coew ad MGll, 996. T appra xplo e ae of e oogal MG approa o dre load aog   aed o e bologal eavor of e e  e e opao o f-  afao of o orqe ao evera ow a jo Te opo ae e ologal preded fore ad ad le fore e a ao o ble o afy ree-deoal oe axe a evey e leg of e lar pe. e Oe e reedeoal oe ave jo eeover aged ad e for deerd, a aay of pe aly  perfored y oparg e oe of wor poed o e pe rog perrao w e oe of poea eergy xg  e ffeed ol  o gly evolved of pe ode provde e oea/ergoo w g o jy ea aed  ay (a wee y Colew ad MGll 199  a we pg p a ve lg load fro e oor. ve og pae ave rpored a jy fro de  a edg over o e a oe prevo odelg approae were eve ol o e daage ad jY earo proded fro large load ad oe ow a oaal x plaao  avalale o expa e eqe e daage, ad a eod  val able o dee e r of  appeg. Alog e roe e of  yp of opaed odel y ergoo  o feale   ef  raed e) for aayg dvdal worer ad deyg oe wo are a eevaed r of jY eae of faly peroa oor paer

Simple or Complex Models?  ary, e oplex odel provde a ool o vegae e a of ry ad e effe of eqe drg aeral adlg o e r of jry. T o oplex ad ge evolved odel provde g a o ow jry or  all pe of eav ad lg load O e oer ad, e pler odl, wl ar fg aray, a e a powerfl oo for roe rvelae of pyal dead  e worplae   e wel erpreed  ea ae for er ao a

58

Low Back Dsordes

nsrins Bihnis n rnis n h fl nn f sohisiin n ds Th hi f whih n  s ns n h ss in qsion

The Cha ll enge Before Us In his hr I h sriz n riqd srl pphs fr hr sss nd lilis Th hi f h s pprpi l dpns n h bji  hn  ny rniss n insril nins bli h inil iss loin is bs for ll s ing h  dir hir innions or kin ll jbs sir his np is fly Bilil isss rqir rpd ldin nd srss o b hlhy Virlly ll risk ssssn ls nsr ny h risk f o h l Rsk ssssn ls h sry  il ldin fr pil hlh  s srin o r Th hln is  dp  wis rs k sy  fili pil iss dpin Mr rs ssssn os il  dlop in h fr bsd n h s hlhy inon f wrk nd rs This ill  hd by firs ndrsning h bihnil philil, n psyhol prrs f in jy n hn rfn n hn lyin hs wis hohflly

References Cholewicki, J., and McGill, M 992 umbar posterio igament involvement dun extemey heavy lfts estimated from fluooscopc measurementsjournal Q/Biomechanics, 2 1 172 Chowick, J., and McGi, .M. 994) EMG assisted optimzation: A hyrid approach for stimatin muscle forces in an indeteminate iomechanical moel joual oiochanics 27: 287 28 Choewick, J., and McGill, .M 996 Mechanical stabliy of the in vivo umar spine mpication for injur and chronic o back pain. Clinical Biohanics  0) 1 Du, J, Doues, M., and mitt, P 994 gonomic uidelines for the pevention of dicomfort of static postues can e ased on enduance data Ergonoics 37: 8078 Grood, E, and untay, W. (93) A joint coordinate system f the cnica descipion of thre dimensional motions: Appication to the knee jornal oBiochanica Eninng, 0: 3 1M

Honsa,  Vennetteli, M., Mott, N, ivera, D., Niechwie, E, Wagar , Howard, M, Zettel, J and McGil, M 99 The effcacy of the IOH handto-container coupng facto ocdns of h 30 Annua Confeence of the Human Factor Associaton of Canaa p 3 Wnner of HFAC/ ACE Best Unegraduate resentaton and HFAC Ontario Chapter Award) Kaowski, W 99) Psychophyscal acceptability and percepton of oad heavnes y females Ergonoics 34 4): 487496 Karwowsk, W 992 Comments on the assumption of mutiplici o rsk factors in th draft revi sions to NOH liftn ude n umar,  (Ed.), Advancs in industrial roois  say London: aylo and Francis Kawowski, W, and onpatanasuesa, N (99 The effect of colo on human pception of load heaviness n Mital, A Ed), Aans in inusria rgonoics and safY (pp. 673678) on on aylor and Francs eamon, TB 994 Research to reaity in a critical review of the vaity of variou critria to he prevention of occupationay inuced ow bak pain sabity rgonocs 37 2) 9974 Ma·a, W, Fine, L., Ferguson, A, Waters, TR 1999) The effectiveness of commony use lftin asessment methods to identf industria jos associated ith elevated risk of lowback disorers Eronoics 42 ) 22924 Maas, W, Lavende, .A., Leuens, .E, et a (993) he role of dynamic theimensona trunk moton in occupationay related lo back dsorders: he effects of workplace facto trunk potion and trunk moton charactestics on sk of nuY Spin 8: 61762 Marras, W, Lavender, .A., eurgans, .E., Fathallah, F.A, Ferguson, A, Alread, W, and Rauu L (99 Biomechancal risk factors for occupationally eated low back disorders rgoomics 38: 3774]0

BD Rs Assessmen

 59

M' WS n Soeic M 1991a A ee-denonl otion odel of lod on e l pine l: Model ctue Huan Faco 32: 23-13 M', W, nd Soec, M 991b A tee-dienionl oion ode of o on e ub pine : Model tctu uan aco 32: 139-49 Mill SM (1992 A oeectcll bed dnc ee-enion oel o peict o on u pne iue ding el ending Journal ofBochancs 25 395-41 Mil SM 99 Te bioecnic of o bck in Iplicion on cent pctce in indut nd e clincJoual (Bochancs 3: 46545 Mcill .M nd on RW 196 Ptiioning of te L4/L5 dnic oen ino ic ligen ou nd ucul coponent ding lifng Spn 11 666-6 tonl Inite o Occuptionl Sfet n Het (IOSH) (19 Work pccs U for anual fng. epten of Het nd Hun Sevice (HS) NIOSH Plicon o 1-122 on  Well R enn P Fnk, P Snnon, H., n e M 99 A cpon o pek v cuultve picl ok expoue k fco fo e epng of lo ck pn in te tootve nu ncalBohans 13 561-53 Snook . 9 Te egonoc ocitTe ociet Lecte 19 Eronocs 2] 2: 9395 Snook SH nd iello M 991 Te eign of nu ndling k: Revie le of x u cceple eg nd foce Eronocs 34 9: 119-123 We T Pt-Andeon  g A nd Fne L 993 evied OH eqtion o  deign nd evtion o nu ting tk ronocs 36  9-6

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Reducing the Risk at Work

A

s I e sgese n peos cpes mny o he cssc nscons om expes" o lng (o exmple en he nees n no he c e n mos cses nonsense n c e e occpon lng ss cn e peme hs y The esng gey s h cncns o he expes lose cey n he eye o he oe he o  nos she cnno o  e o h  y Se  s ec  om he o o ncee o ps ns lescos nn so o scenceon shos h sqn o cn he n pysoe ologcl  The eenng he ccescs he lo  my no een ece los Sqng s no lys e s choce o poson  epens on he speccs o he s (sze egh n ensy  he oec pc n plce locon nme o eeons ec Fo exmple he le's l see ge 86 le n hs cpe) my e me peele o ecng ne lo n enn e nees n eeng he c sgh o smeone epeely ln lgh oecs om e loo Recng n n mpong ncn o pens h l c pn nole  cmnens • •

emong e sessos  cee o excee me nhncng ces h l hehy sppe sse

Ts chpe esses he sse o peenon specclly ecn he oelng sessos  cse occponl D Ae een lessons m e lee n esenng e scenc sses I l e o ses o gelnes one  es n o mngemen Fn ly I  e  el noe  ennce eece nessnhe o cnslns The ss poe n lls cpe esl n mesccel nj peenon ogms The pcone o consln o emlys hem ll sn o m hs ees Uon compeon o hs cpe yo l e le o omle scenclly se genes eece o ny cy h ece he s o occonl lo c oes Fhe yo l e e o n so ll e le o o he ls h cse egonom c ppoches o   l nlly yo  l e  moe e ece cnsn y hnessng he el expese o e oe

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ow Back Dsorders

Lessons From the Literature Why os indstry ar abot th aks of workrs? Cotiivns in h n onoy rqirs ing pofitabl and for any h only ay o nhan profit is o axiiz los ontrol A ajor sor of losss o North Arian indsty i ork injry hih rss in ir osts for onsation an indirt osts of hirin an rainin lant workrs and rd rodtivity  to lor d an in rasd rros For this rason prvntin injry and prooin th rai rtrn to wok of injrd orkrs hav bo a ajor fos for indsry. Bas ak injry rrsnt an noros ost in oh ra olars an sffin oanis ar aliz in h nfis of sorting injry vntion and habiliaion roras Follow ing a a nr of stdis tha hav addrssd th isss that t  xain if sh ora ar to  sssfl

Ergonomic Studies f LBs a assoiat wih loadin thn hans in oading hold han inj an asni rats Bt srisinly th litatr dos not ovi lar idan for rahin hi ojtiv; it n intrration. Th taditional ronoi aproah is to salish a irion that if apli in th job dsign old la o a tion in inidn ra In a viw in 1996, Fank and ollag sst that odifi work with lor ands an b sssfl in rdin th n of injris bt hat oth hans sh as organizationa aars ad it diffil  onld that physial dan hans aont for any rortd diffrns This is as vry fw stis hav siy altr jo dans Frthror Winkl an Wtgaar 996 not hat th iplntation of ronois an ad to hat hy all an rgonoi itfall That is th n ronoi onsiosns ass any orkrs to rport onns that thy di no viosly raliz wr a rsl of hir job sia tions Ths any nwly iplnt roni inrvntion rras ha v rslt  in a tpoa ris in sloskal isorrs. This fft aars to hav on fond any sy of rgonoi ffiay of insffiin ation. Th nr of goo invstiaions oning th ffs of jo hang o th ilnation of rgo noi inis is also ow bas sh rsarh is vy ti onsin an iffi l to prfo on si Nonthlss svral ni stis aiy y dontin only th ff of ro noi jo din. For xal in a rort on a sris of stis on orkin won in Noway Aaras 994 nod a olltivly dontd ion in sik lav d to sloskltal trobls fro jo rdsin spifally fro 3% o 3. an a rtion in oy trnovr fr 30 to 76

Rehab and Prevention Studies Loisl and olas  99  on a vY intsting a n iortan st y in hih a ranoiz trial dsin ith for os On o thy ith sd ak injris rivdontol inial" intrvntin onisin of a visit t aro ak of pain siais ak shool and fntional habilitation hray Anohr o r ivd an oational inrvntion onsistin of a visit to an oational hysiian an thn an ronoist to ariv at ronoi soltions A thir ro h fll inrvnion op" riv oh of ths approahs an h foth ro r ivd al ar." Th grop rivin fl intrvntion trnd to rlar wok 241 ti fast than th sa a g athoh th spifi fft of oational intrvnion ronois aont for th ars pootion of this rl wih a ra ratio of rtrn to rglar ork of 9

Reducng he Rsk at Wok

6

Thos paying or injry govrnnt agnis and opnsation boards an th insr an nsty) od rasonably arg ro this vidn that to rd osts ar or th injrd bak shold b rovd ro mial hands on th dis hav rld ot r ag ondtons sh as tors) and givn to rgonomists! Tong-n-hk as this statmnt ay b ts pont is worthy o p onsration oplly th last ston o this book will provid ls or or aios dal intvntion. ras asing and brasr (99 rviwd th itratr on th rol o odiid work n th rtrn to work an rat as hgh alty th oisl stdy as wll as th stds o Baldwin Johnson and Btr (99) This lattr rviw onldd that oi work involving th odiato o sloskltal oading) is tiv in aitating th rtrn to work o disabld workr. In ation to workpla dsgn moi ations workpla ntrvntions ay bn t ro arssing th prsona ovmnt stratgis o ah workr. n a asnatng sty Snook an ollags 998 monstrat that o  patnts randomly as signd to a grop that ontrolld th aont o arly-morning mbar lxion th xpr ntal grop had a signiiant rton n pain ntnsity ompar to a ontrol grop Whn th ontrol grop rivd th xprimntal tratmnt thy rspon wth siiar rdtions Ths s yt anothr xap o ho prsonal spin moton pattrns and loang postr an nln whthr th prson will bom inj Th nxt ston bns notions o job sign with prsona ovmnt stratgis to r loaing an th risk o B

Studies o n the Connection Between Fitness and Injury Disability It is rtl to sss brily th rol o itnss in th link btwn njY an isab ity  Althogh sv ral stdis hav shown li nks btwn varos  tnss ators and th  inin o LB .g  S n t al   998, who s how that hig hr Omax sors wr link to Bs) ths ross-stional stis annot nr asation � robaby th ost idy t longitdnal sty was rport by Cady an o lags (1979 ho assss th itnss o os Angls irghtrs an not that thos who wr rat or it" ha wr sbsnt bak ins owvr hat is not wily ot by thos itng this stdy is that whn th mor t  bom injrd th injY was mor svr rhaps th mor it wr wlng to xprn highr physial oads Svral hav sggst  that a psyhol ogial pro is assoiat  ith bng it .g. armr t al. 98 ghs 1984 Ross and ays 98 ong 1 979 an that th nit ay opain or abot th mor inor ahs Along thos lins so athlts hav monstratd th ability to opt spit injry Btt an olag s  99 rportd  rikt bowrs wth pars ra trs who wr stil abl to ompt s ths d to thir spr itnss an ability to ahiv spin stability or thr mntal toghnss? rhaps t is both Th iss rmains nrsolv. t is also intrsting to not that prsonal itnss ators appar to play som rol n rsttim orrn Brng-Sornsn (94 tst 449 mn and 479 womn or a varity o physial haratristis and show that thos with largr aonts o spn obi it y an owr xt nsor msl  nran inpnnt a tors) ha an inras orrn o sbsnt irst-tm bak trobs. oto and oags ( 99 rah smilar onlsions. It wold appar that msl nran an not anthropotr varabs ar prottv

LBO Prevention for Workers This ston adrsss a st o sss that ar sntiialy jstiabl to r th rik o opatonal LBs.

6

Low Back Dsorders

Should Wokes Avod End Range of Spne Moton Dung Exeton? Generaly he answer o whether end range of motion should be avoded s yesor several reasons Maintanng a more neutrally ordotic spne wll maxme shear support ensure a high toler ance of he on to wihsand compressve forces eimnate the risk o igamentous damage snce th e lgaments remain unsrane d elimnate the rsk o disc hernaion since ths is associated with a ly exed spne and uatatvely emulate the spne postures that Oympc avod nury (see fgure 8, ab forthis an lusraionliters of a adopt flexedtoand a neura spne Unfortunatey ssue has become conused with ssues such as wheher it s beer to stoop or suat for example Anoher source o conusion has evoved rom the common recommendaton to perform a elvic tilt when litng; the scientifc ase or this cnically popular noion s nonexistent Perormng a pelvc tilt increases tssue sresses and the risk o inury! Wha spine and h p posture best m ini mizes the risk of injuY? We do know that very ew litng  asks n ndustry can e accomplshed by bending he knees and no he back hermore most work ers rarely adhere to hs echn iue when repeve lis are reured a act hat s ute probably due to the ncreased physologial cos o suatng compared wth sooping (Garg and Herrin 199 However a case can be made or preservng neutral umar spine curvature whie lng specialy avoiding end range ims o spine motion about any of he three axes hs is a derent con

Fge 8.1 Feig te too volve ete p leo o pie eo, o bot a A etal pe wit ip feio  Spie leio

cept rom trunk ange as he posure of he lumbar sne can e mainained ndependent o hgh and trunk anges he leraure is confused between trunk ange or inclination and he amount o lexion in the lumbar spne Bendn over is accomplshed by ether hp exon or spine exon or oth t is he issue o specc umbar spne exion that is of imporance here Normal lordoss can be onsdered to be he curvature of the lumbar spne associated wh he uprght standng posture o be precse the lumbar spine s slightly extended rom elastic euii rum when sandin see Scannel an Mill n press In figure 82 a ware house worker i suess fuly sparing hs spine y avodng end range of spine moion even though he is not bending he knees has accompshe orsohe flexon by rotain aout Fge 8   waeoue woe i ot bedig te ee, yet e i pag te pe by electg to bed ad otate abot te p; te lmba pie i ot leed

Reducng the Rsk at Work

65

he hips n igue .3 a eighe s demonsran a spne sparng echniue gure .3b vesus a spne-daman ec nique (igure  3a o ling exingushes. Chae   oes uher occupaionspecic examples e.g. he conrucon workers demonsrang sine-spaing oues in iue  1 .4 . In chaer 5 I explained he load dsbuon among he issues o he ow back O nees here are he damaic e ecs on shear loadng as a uncon o sne cuvaure. ecal he oowin acs • A spine ha is no ully exed ensues ha he ar

Fge 83 This frefghter  wo s flexing s lumbar regon, s loadng te passve tissues and nceasng hs sk o bac toublesb voidng ul lumba flexon and otating about the ps spares te spine

Fge 8.4  god-medal lif by Naim Sueymanogu in Olympic weightlfting Hs umbar spine is ocked in neutal and te motion takes pace about the ps and nees

lumboum o o heovide longssimus horacs poserio and iliocoal umbom ies ae abe a suppoing hea orce on he superio veebra while ull exion causes he nerspinous igamen comlex o sran mosn an anerio shear oce on he suerio veebra. Fo hese reasons avoid ng ll exon no only ensures a lower shear od bu aso elminaes lgamen damae. • A uly exed spine i sgniicanly comomid n  aily o wihsand compressive load • Because heniaion o he nuceus hugh he annulu i caused by repeaed or prolonged ull exion avoidance o he posure mnmizes he risk o hernaion a cumulave rauma pobem and minimizes he sresse on any deveon annula bulges. Oympic liers provde a convncn example o he eicacy o avodn lumbar lexion in liing hey ock hei ines in a neura posue and emhasize roaon abou he hs see gue 4 ling enomou weighs wihou nj. Te am ulance aendans in igu re . 5 ae also parng h eir ack y lockng he lumbar regions o avoid exion

Fige 8 Tese ambulance attendants ae attempting to spae teir backs by avoidng umba flexion and iftng together to shae the oad ey have aso been taught to gty contact the stabilzing abdomina muscuatue

66

ow Back Ds oders

Fge 86 he golfe's if has been documen ed o minme low back moon and educe he oads on e umba issues by sng e leg wch is canileveed behnd as a coneweg; e hips ac as a fucum o ase he oso o pigh Tis s an efecive ecniqu e fo epeaed lfng of lg objecs fom floo  leve Mos s adhee o he genea insucion o bend he knees and keep he back sag a no consideing he spine-conseving benefs of he gofes if b

hus he iporan issue is no wheher i is eer o soop it or o sua li; raher he ephasis shou e o place he loa cose o he oy o reuce he reacion oen an he suseuen exensor orces an resulan copressive oin loain an o avoi a ully lexe spine Soeies i ay e eer o sua o achieve his; in cases in which he ojec is oo are o i eween he knees how ever i ay e eer o soop lexin a he hips u always aviin ull uar exion o iniize poserior iaenous invoveen For a more cprehensive iscussion see McGi an ippers 1994; McGill an oran 197 ovin Noran an McGil 991. e anoher spine-sparin iin posure is he olers i hich reuces spine loas or repeae litin o lih oecs see iure .6 a inney Calahan an McGil 1996. The hips ac as a ucru in which one le is canilevere ehin wih isoeric usce conracion orin a couneeih o roae he upper oy ack o uprih

What Are the Ways to R educe the R eaction Mo ment? A popu ar insrucion i s o hol he loa close o he ors o when hanlin aerial This is ioechanically wise; a reuce lever ar o he loa reuires lower inernal issue loas necessa Y o sup port he reacion oen Bu phrasin he principl e i n ers o holin he loa close resrics he noion o liin asks The real ioechanical prin ciple is o reuce he reacion oen When phrase his ay he principle is now applicale o any ask involvin he exerion o exernal orce

Directing the Pushing Force Vector Through the Spine When pushin a ca hanle irecin he pushin orce vecor hrouh he luar spine reuces he reacion oen an hereore he issue loas an spine loa see iure .7. In conras a pushin orce irece hrouh he shouler wou no e irece hrouh he low ack see iures . a; his ors a ransmissible vecor he are perpenicuar isance ro his orce o he spine causes a hih reacion orue ha is aance y uscular orce his iposes a corresponin cmpressive

Reducng he Rsk at Work

167

naty on th in irting th tranmiil vtor through th low ak ru thi momnt arm (and th momnt) th mul or an th in omriv loa. Othr xaml rom vyay ativiti inlu th thniqu ud to on a oor; irtng th ulling o through th low ak  aring ( igur .9 a-). Anothr xaml i vauuming whih i otn ot y our atint  to xara t thir ymto m Hol ing th hanl to th i rat a larg momnt arm or th uhing/ulling or; thi havily oa th ak  igur .10a). ting th uh/ull o through th low ak

Fge 87 Psg throg te hads bt directg the orce vecto to pass thogh the ow back mmies the low back momet (ad mimes the msclar loads)

Fige 88 Pshig or pg orces that pass by the spe wth a lage momet am esre a hig momet ad coespodig g mscle orces ad spie oads a Psg orces dected togh te ow back mime te momet ad spe load b

Fige 8.9 Opeig a doo by drectig ad orces tog te low back spaes te spe a May peope ae o t tagt ow to optmie ts pcple dg te peormace o daily tasks Istead, they saciice teir spie by opeg the doo so that the orce is ateral to te mbar spie creatg a twistig torqe b o prodce a pg orce tat passes over te low back 

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ow Back Dso rders

mnmes he momen arm see fure 10) and removes the loas that ensure tha pa tents reman patents These exampes dem onsrae how hs poerful ut rarely pra e tehnue of skle onrol of the ransmssle vetor spares he ak

Diverting the Force Around the Lumbar Spine Sll other vey effetve ays exst to redue

Fge 8.10 a Vacmig is of rportd as pobmaic fo bad backs T tasmssibl vcor i is xamp as a ag momt arm wi spct o  back ad qs larg twstg toq forcs (casig pai b  rasmssib vco s dictd tog t low back mimzig  load ad  pa ad ablig vacmig

Fge 81 1 is as qirs a wok to f a avy saf wl ao work slids o a co from  d A ig cidc of bac obs moivatd o cosig commdao to stall a ba fo  foo wic is paa flxd o ais t saf ow sppod o  ig  forcs ow asmit dictly dow  g, comply bypassig t arm ad spi lkag

the reaon next examples onstrate howmoment workersThe skllfully sare the dem lo ak y dvertn fore aroun the lumar re on hen lftn. The orkers lfn the shaft n a paper fatory n fure 11 re mnmzn he reaon moment y lftn the shaf th her hh y pantar flexn he foo In ths way the weht of the shaft s ree don he thh to the floor yassn the uper oy lnkae and spne. ror to redesnn the jo he orkers had to lt th shaft th a fores ausn low ak proems an motvan our nvolvement Fure  a throuh c llustrates

Fge 8

Lfig t pat

ca b pfomd wt providd mima loadig dow  spi  ig of  sa is clos o  igt of  ifr's tig w i a sqa posiio a  pat's pvs is pld ad sid oo  ifr's tgb ad   lift sads p ggg  patt's pvs ad mimizg t focs p  ams ad dow t spi is spsparg cq is rsrvd for pais wo a abl o sad

Reducng the Rsk at Work

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b Restg the Fge 8.13 a Shovelg sow wh a age mome arm o the oad o the sove loads the bac arm o e high direcs he oces o e grod bypassg the arm ad spie liage

ho a ok an pfo th a anuv to if a patint. Obv that th lift i pllin th patint plvi onto hi thih and tandin alon ith th patint Not that patint lift annot b pfo ith nival thniu in vry patint i iff nt an an of vaiabl aitan Minial fo a tanid down th pin hovlin no by tin th foa on th thigh invov th a pin-pain pinip  fiu .3 ab

Redung the Lod Finally wok u kill to du th atual load an hand fo whn liftin la ojt So tak an b pfod y liting ony haf of th objt a a ti Fo xapl hn loading on lo onto th bak of a uk a wok oul lif jut on n fftivly handling ony half o h l wiht of h log and pla i on th bd Th wok ould thn alk aound to h oh nd of th lo an lif whi iding th o in to th b  figu 4. ah lif i half of th total oad. A un of unloain a i ato donta th a hniu h full wiht of th objt i nv lif t  fiu .  5 a f Th ok l tin h inifigat hon in fiu  a-b oftiltgavity it up onto an   aiin it6 nt toth wih th ini tial ift ing hight ifing f o thi hih tating poition du th naY ont Th onpt of iniizin th ation ont i o uh o o but than iply tlling popl to ho th load lo to th body Fge 84 Ths g oads e og io he truc by ifg oly hal is weight a a me Fst she lts oe ed oto he truck e she ifs e oer ed ad slides the log oo the bed

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ow Back Dsor des

Fge 8.1  hi wke unlad he egea m he aile whu havng  li  ul wegh He "walk"he egea n  cne  he edge  he ale whee he alance  ve he lip  he ed a Nex he lde he egea dwn he ae' agae  He wak he eigea cea  he ale and eave  andng upigh whle he eeve he dly He puhe ne edge  he egea up ju enugh  lide he dlly unde(d) i and  naly, he and a cwke wheel he appance awayf

Should One Avoid Exertion Immediately After Prolonged Flexion? Recll ht prol onged exon c uses oh lgmentous creep nd  re dstruton of the n uce us wthn th e nnuus (see chpter 4) In ths wy he spne tssues he  lodn memory Further recent edence from cson nd colegues 200 suggests tht prolonged lexon mod fes the extensor neurologl re sponse nd cuses muscle spsmn t lest untl he lmentous creep hs been restored n ths cse  s seen hours Spne stbly ould e

Fge 8.1 6 h man li he min-eigea y lng i up n an edge a aing  cene  gavy gehe wih he nal ng heigh ing m hi hghe ang pin edce he nece ay mmen  he man can each he andng pin wihu damage  h ack 

comprom durng ths prod nd he rs osed nnulus dmge remns emporrly hgh If possle fter olonged stoopn or stn cttes people should spend tme tndng uprght before ttempng more strenuous exertons For exmple t would be ey unwse for the rdener

Reducng the Rsk at Wok

Fge 87 s gadene would be uwse o sand and immed ael if a heav object afe spedng a long peiod of tme in a sooped postue Rathe, standg fo a bef peod and even exendig wil pepae the disc ad posteo passive issues to educe e isk of nju

7

in figure 8 to stnd nd ift  b of pe oss or for the shipper/ receier in igue 8.18 to rise nd i editey egin od ing ets o ong shoud one wi befor prfor ing n exertion? Dt fro Twoy nd yor (982) deried fro c deric spines suggest th ge deys recoe of the spin tissues MGi nd Bro n ( 992 noted th resiu xity reined in the pssie tissus een fter  hf hou of stndin fo owing proonged exionhouh the exion ws extree in n ocu ption context. At st 50% of th oin stiffness returned ftr two in utes of stnding foowin g the sssion of poonged fexion. As not d·n ch  ter 4   ecuse t h

Fge 88 his shppe/ eceves wok is chaacteed b peods of sig followed immediaely by liftng whe a truck mecha cs of he JOIns are modulatd puls up to the loadig dock Agai, by peious odin history one stadig and waing for a few sho uld never move immediat ely o a miutes po o e exeons wll ifing t sk fro  stooped potu re . . educe te sk of iu

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or fte pro onged ttn. Rther one shoud first stnd or en nsciousy extend the spine for  shot period Obiousy peope in certin occuptions such s egncy unc per

sonne of cnnot foow guideine. rrie  n cciden nsty scneiftssuch without the uxuY tie o whis up their bcksThey nd y he to pefor s  50-k hrt ttck icti out of  bthtu! For these indiidus the ony strtey is to oid  fuy fexed spine posture whie driing so tht the spine reins es ppred to wihsnd he iposed ods. his y be done wih ccentuted ur pds in the bunce sets nd with worke tining.

Shoul ntra-Abominal Pressure (lAP) Be ncrease While Lifting? Genery the nswer is no  est AP shoud not be incresed consciousy. Rc the discusion concuding tht AP does not educe spine oding u does c to stifen i gins bucking. y successfuy copeting the rehbiition tining o ced in he fin secion of his book peope cn rin their brething nd AP to e independent of exeion. In this wy ny speciic instuctions regrding brehing n exerion becoe oot points In ost cses AP i rise ntury nd no furh conscious effort is is required A fin cet equied here. Very strenuous ifts if they ust be prfored i require the uidup of AP to increse torso stiffness nd ensure siiy (Chowicki Juuu nd McGi 999 On the other hnd we know tht  substntiy incresed intothorcic pessue ( s occurs with iing wi coproise enous return ( Mntysri Anti nd Petonen 198. Further breth hoding duing exertion rises oh sys oic nd distoic bood prssure (Hs et  988) hich cn b  onrn for soe. ckout is not uncoon in strenuous ifting en though i is not ce hich

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ow Back D sorder s

echs s resp se (McD g et  1985 Ret   94  prpsed tht c t y e de t eeted cetr ers syste fd pressre (A s rses  fd pressre  the spe d p t the hed, wheres Ht, Wdry, d Hrper 944 prpsed tht  crese  cerersp   d pressre gh t cty sere  prtecte f ct ( e  the cseqet decrese  sr pr essre crss the cerer esses cd cty decrese the rs f scr dge) At ths pt ge these sses d  c f f derstdg derte A y be wrrted wth the derstdg f the egte sde effects Extree g effrts  cscs creses  A shd t be perfred t wr

Are isting and isting Lifts Particularly Dangerous? Whe seer reserchers he detfed twstg f the t s  fctr  the c dece f ccpt w bc p (Fryyer et  1983 Trp et  1981) the echss f rs reqre se expt The etc ct f twstg hs ee cfsed  the  tertre wth the  etc rbe f geer t twstg trqe Tstg trqe  the trs c be ccpshed whether the spe s wsted r t Geery, twstg t derte degrees wtht hgh twst trqe s t dgers e he hyptheszed bsed   ert et tht twstg qcy  pse dgers x trqes p brg the x rtt f the tr t the ed re f t F d ceges 970 prpsed tht twstg f the dsc s the y y t de the cges fbers  the s edg t f They repred tht dstr ts f the er rch pertted sch rs rtts hrzAd d ceges  1986 cdcted re deted yses f the s der twst They spred Frf ctet tht twstg deed c dge the s t ed re t s ted tht twst s t the se echs f s f  ctrst, se re serch hs sggested tht twstg   s t dges t the dsc s the fcet  cpress  echc t rtt etrs befre the estc t f thett dsc s reched; ths,frs the fcet s the frst stp stctre t sst fre (Ads d 198 1).   stdy f get eet drg tstg e d  97 ccded tht the gets were der y eggbe str drg  f physc twst Hweer  yss f the 4-5 t by McG d Hdess 990 sgested tht psterr gets y bece ed f the t s fy fexed prr t tstg Geertg twst trqe s  dfferet sse (see fge 89 -b) ce  sce hs  prry ectr drect desged t crete twstg tqe  sces re

Figure 8.9 a wtg the too  occrg at the ame tme tat twtng toque  reqre whc  a angerou combaton b Geeratng the twtng toqe but etctng the too twt  a pepag trategy (an can ao ehance peformance)

Reducng the Rsk at Work

73

ctite   stte o ret cocotrctio Ths rests   rtc icrese  co presse o o the spe whe copre to  eqiet torqe bot other s or epe, t ro  coto o o preos stes icte tht spport 50   the extesio is iposes bot 800  o spi copresso The se 50   the ter be xs rests  bot 1400  o br copres so, t 50   the i twst is wo pose oer 3000  (McG, 199 t ppers tht the ot pys ery to sppot ee s x torqes whe eteg  the it o  o To coce, the geertio o i twistig torqe whe the spe is tste oes ot pper to e o  prtcr c ocer or is the ct o twisti oer  oerte re wthot ccopyig twistig torqe. Bt eert hh trqe whe the spe s tste ppers to crete  poetic coto   hgh rsk Ths s o pticr cocer i seer spots  wi be resse  tht cote t  chpter 9 

Is Liing Smoothly and Not Jerking the Load Always Best? The swer to ths qesto is o We he  her tht  o sho e te soothy  ot erke Ths recoeto ws ost ikey e o the sis tht cceert  o pr creses ts eecte ss by rte o  ito ier t orce ctg owwr together wth the gritto ector Howeer, this y ot wys be the cse. t s posse to   o by trserri oet o  rey oig seget Ater  coeges 996 showe tht whe copre to oice fters, epet teris hers soetes choose techiqes tht ke ore eciet se o oet trser. They o ot wys it sowy  soothy Top  Chp 969 reerre to the cocept o oet trser rg it, s hs Griee 975, who coe the ter kinetic  ter, McGi  or 985 ocete tht ser ow bck oets were possbe  ceri cses sg  ski trser o oet or epe, i  o is wkwry pce, peps o  work te 75  (30 i ro the worker,  so, sooth it o ecesstte the geertio o  rge br extesor torqe or  egthy rtio o te  sittio tht is ost streos o the bck Howeer, the worker co t this o with  ey o r extesor oet or qte possy o oet t   the worker ee orr  pce his hs o the o with et ebows, the ebow extesors  sho er sctre co thrst pr, iitit g pwr otio o th e trk to crete both ier  r oe   the pper oy ote tht the o hs ot yet oe). As the orker strhtes his rs, copig tkes pce etwee the o  the re trk ss s the hs the strt to ppy pr orce o the o), trserri Figure 80 iig a awkwady paced load slowy and smooy as common wisdom suggess compromises e bac aer soe, or , o the oy oet to acceeaing e orso rs and he asferig e momem o the o  csg it to e ifte wth  e oad as e ams sagen ca redce e spne oad Acceera erk This echc soto ws ing he orso and he load a e same ime is poor echique ha proe to be eecte i  e ery olaes s picipe ad causes ighe spie oadng ese eperet  y reserch creer. The poogaphs a and b ae rom a ealy epeme n he aor's eseach career perso show  ire 820   b s

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ow Back Dsor ders

destrtig  tsk  which the d c e ited sw hich wd d the w ck d r wth the kieic ft teche which i crc perred wi sre the bck (Ois the rkers  he de's d were t ssist the esreet  bd seet eet This high skied ierti" techie is bsered ite  et thrgh idstr d i se thetic eets sch s cpetitie weighitig t it st e sressed tht sch its re cdcted  high prciced d skied idids.  st cses cceerti  ds t decrese w bck stress i the  er descried is t sie r the erge idid cdctig the iti chs  d iig The e-trser teche is  skied eet ht eire prc tice it is ese  r krd pced ighter ds d ct be stied r he  is. Aher echic re shd e iegrted it the sis   dic eche. The tisse prpert  iscesticit ebes tisses t sst hher ds whe ded ck (Brsei d rke 1968 Tr 9) sgested tht is cestict  e sed t icrese the rgi  set r spe ir drig  highr stri re t ctied tht icrrtig this pricpe i iig teche shd eped  the rte  icrese i spi stress the gde  ek sres d its drt. Tisse scestict es th der ster g he tisses d t he tie t  er ee whe the gi tde  h e rce s hig h  this w the cric ees  tisse derti reired t cse dge re  reched B ie rii i respse t d rte g the tisses  g diids  speciic gidce petiig t ct d rte c e ered here The istrcti t ws it  d sth   rib rest i the est risk  ir. deed t is pssie t ski rser e t  wkrd ced ect t psii the d cs e   the d ck  d iiz the extes r re reired t sppr he d.  ddii tisse iscestci c be potec ie drig higher d rtes Cery redig the extesr et rere  spprt he hd the dd is pr i he redcg risk  iy this s best ccpished b keepig s cse t d the s ssibe

Is There Any Way to Mak e Seate Work Less Demaning on the Back? Pred sitg is pretic r the bck rtte this ct sees t be rther kw i the ccpti wrd Thse recerig r ck iries h retr t died wrk re te gie ght dties" ht ie prged sitti Whe sch dties re perceied s eig es  the ck the c e r  t. Ee thgh he retrig rker sttes ht he ct terte sitig th i ct he wd be re crtbe wkig d ee itig he is ccsed  igeri Ths is the rest   sdersdg  sitig echcs

Sitting Studies Epdeigic eidece preseed  Vide Nrie d Trp 990 c eted the icresed  disc heriti  hse wh perr sedetr bs chrcterized b sittgrisk Kw echic chges sscited with the seted stre cde he wig •

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crese i  itrdisc pressre whe cpred t stdig pstres Nches  1966 creses  psterir s stri (Ppe et  19 Creep i psterir pssie tsses (McGi d Brw 992 hich decreses terir/ psterir stess d icrese s sherig ee Schtz et    199)

Reducng he Rsk a Work

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7 5

Posteior migrat ion of the mechani ca fcm Wider e t a  , 988)  hch re duces the mechanica adantage of the etenso muscuatue resutin in in ceased compressie oading

These changes cased rom poonged stng hae motiated occupaiona iome chanists attempting o edce t he risk of inur o conside  the duation o sitin as a risk facto when designing seaed ok A ecent poposed guideine sugstd a sitting mit of 50 minutes ithot a beak ahouh this poposa i e tesed and eauated in the fuure

Strategies to Reduce Back Troubles During Prolonged Sitting We hae deeoped a thee-poin appoach for educing ack toues associaed ith proonged sitting  Use an ergonomic chair b se i properly (very few acally do). Man peope hink that the shoud adust their chair to ceate the idea sitting sture Tpica the adust the chai so that the hips and knees are en t 90° an the torso is pight see fige 8.2. n fact this is often shon as the idea poste in man egonomic tes. This ma e the idea sitting postue bt for no onger than 0 minues Tissu oads mst be migrated fom isse to tissue to minmie th isk of an singe issue accumuaing micotrauma This is ac compished b changing poste Ths, an egonomic chair is one tha faciitates eas postue changes oe a aiet of in anges see ige 822 Caahan and McGi 200a docu mened the ange of spine posres tha peope pica adopt to aoid aige. Some hae hee o ou pefered anes. The pimar ecommendation is o contina change the setins

gure 8   a ting pou (90 angl a  ip, kn, an lbow) crb  mot gonom gT  ronou;  al ing pou  on a nvolv vaiab pou

on the chair Man wokes contine to beiee that hee is  inge best poste o sitting and ae euctant to t ohers. This is of course, nfonate as the idea siting pose is  aiabe one. Man empoees need to be educaed as to ho o change thei chais and o the ariey of postres that are possibe 2 Ge o of he chair. There simp is no sstitute f getting out of he chair. Some uideines suggest erformin eecise beaks hie seaed and some een go as ar as t suggest eing he torso in a stetch This is oth nonsense an disastos! A est beak must consist of the opposite actiit to reduce the imposed stessors tension eiees posterior an nuus sress bu more eion whie seaed increases it The recomm ended beak that we hae deeoped inoes stanin from the chai and maintaining a eaed standin osu fr 0 to 20 seconds At this stage, some ma choose o pfom

neck ros and arm windmis to eiee neck and shouder discomot from heir desk ok. The main obecti is to bu some time to ao edisution of the nueus and educe annar stresses The peson then raiss the ams oer he hed se figue 823, a-c and then pushes the hands upward to the ceiing B inhain deep, one i find hat the ow back is fu etended. n his wa the peson has taken his ack though ente and pogessie umar etension without hin een aught mba position aaenss o een undestanding the cone Sme i aue that in their obs the cannot stand and ake a brak th mus continue hei seated ok. These peope gnea i need o be shon he opportunties

76

Low Back Disorders

Fgure 8.22 G d pure fr pnged iing  a arabe e a migrae he iernal ad amng e ar iue Pibe ig pe p are w

o tig For exme the oud hooe o  he the hoe ri   i. With these  x the wi oo  the oortuit rtie this rt o good ie hth.



3 Perform an exercise roine a some e  he workday Md ou  ide u i thi i th oi is uise (ee th eiou uiei A oo r k rou i rst i th t etio o th ook.

Som e Shor-Answer Quesions Th ooig qustio  thir er roid hr uie to u th k o ouo  B.

Redung the Rk at Work

 77

Fgure 823 A strategy to twart te accmulaton of dsc stesses rom prooged sttig s to stad (ote te orward atagic postre oten obseved ater sttig a reach o the ceilng b stetc pushig te hands pward, and then inale deeply  is sequece whe peromed sowly cases a getle and progessve exteso o the umba egon and dspels te stresses o sttig

A ch   • s it advisable to maintain a reasonable level of ftness? o  ike to iee tht hiher e of fitne re potetie for o ck toe, it i rue by oe tht the itertre i not trony uportie. Thi i or eer reon. Mny cinic tri in hich the interention  in to en hnce tne cty choe exercie tht nknoingy incre th rik of pin d For expe ny ue tht enhncing bdoin trenth   oo ie n dre thi go by precriin it-p exercie itu i d th ck of ot peop; they i not incr ck heth Perhp thi h ct  n rtict iin th iterture nteretiny nouh the ot recent tuie tht h ued ioechnic eidence to eeop exerciepticury tiiztion xr cieh hon the to be eficciou n fct,  recent reie of prenti interention y Linton nd n Ter (200 get tht echon xrcie i th ot poeru trtey or preentin occption bck tro A t pin intined ith hthy nd ie otor tte on ith hihr uc enur nce i protectie. horly aer rising from • Shold onel or perform extreme torso bending s bed? The ner i no Rec the iochnic o diy chne in the i 

dicued in chpter 4 the dic re hydrophiic nd ibie fui oiht. hi i hy peoe re ter in the ornin thn hen they retire t niht Thi i o hy it i ch ore ificut to bend in the orning to put on ock on copr to tkin the off t niht the bendin tree re uch higher tothr ith the rik o dic d Thi irn rition in pine enth nd the biity to x r h ben e ocunte A preioy noted, nook nd coeue 99 n th trtey to retrict ord pine fexion in the ornin to  e ffectie in reuc in ypto in  group o bck-troe ptient

8

ow ack Dsorders

• Should workers adop a lifing sraegy o recrui he lumbodorsal fascia or involve he hydraulic amplier mechanism?A nted n e 0 in chter 4

thee chni he been hn t be untenbe prp fr rn the bck Whi e ti ttet t trn rker t inke thee trtei, thy h itte cientiic uprt in ny ce uch trtie i be detrint A • Should he runk musculaure be coconraced o sabilize he spine? ntd n chter 6 the ner i enery y On pge 7 in chtr 4  nted tht thuh uch cctitn ipe e nty n the ine, it i t r the pine t py thi ric t enhnce tine nd ritnce t buckin n to reduc the rik  ther untbe behir H uch ccntrcti n i  necer? A  nted in chtr 6, in t tk, ufficient tbiity i enured ith ery det unt f ccntrc tnehere in the nitude  5% t 1 0% f MVC for th din  nd ther ntnt Achen dded t ine i n the in e throuh ccntrct ion i he rent inuie tht cn theri rut een duin th itin   ey ight bct, nzng, r tying ne h. Of cure, here ther i th tent fr upri din r hnding nnriid teri r hir d, th cctitin g nitud ut incree Dged nt tiue  require highr  f cocntrctin t id unte nt behr. Th necey ee  cctition ud depnd pecficy on the tk nd the hitry f the ndiidu hu, hty ccntrctin the tiizin ucutue upn exertn i  renbe udn thi hud be ce uttic fin tbiity trinin r the h d not ntury tffen

LBO Prevention for Employers Not  reentin trtei cn b iented y by rkr. oyr t, y  re, hich   utin d hre • Provide proecive clohing o faciliae he leas sressl posures Wrk er te hnde teri tht i t nxiu r t hzru t hd ce t thi r bdie o r xpe,  he been in d i n ce in hch ork er hed dirty teri y fr the bdy t kee thir ht cen, unncry oin their bck he outin  t pride rotctie cer t r rker' bck Lthr n r hu f the teri  hr t fter hdin th d int the do n,  r het t rker, fr exe Knee d r o or rne rk on th rund Once th epyr h ridd the nece rotcti cth in, orkr i iure ut th rity f orking tue tht cn r thir bck Ch • Should abdominal bels be prescribed o manual maerias handlers? tr 8 cntin  thrugh dicuin  thi tpic •

Opimze conainers andpackaging of raw maerial o spare workers' backs

Often n the din f the indutri rce, pring the int  th orkr i nt cnidrd When cniderin the indutri roc, ee if hnded tri cn b buk continrizd Cn r tri  hndd in er un r in bund of diffrent dinin? ete it i  ipe  cnttn th uir to find ternt y  ckin ter tht fter hndin in  y tht cne th bdy nt Th purchin dertnt y  re in rducin nury Bin nd cntiner th fdin de hep if rt ut be pickd ut f th bin. •

Encourage workers o pracice liing and work/ask kinemaic paerns.

Se indidu iy d nt , bend, nd rk in y tht r thir n In  recnt tudy (McGi t , n re),  td tht rkr ho h  riu hitoY o bck troube er re iky t dot tin ttrn tht rutd in

Reducng the Rsk at Work

 9

higher sine loads! Kinemaic paerns need o be pracced and roove ino movemen reeroires. Remember he expression quoed erler rac ic does no make perfec u pracce makes ermanen") Some eoe mus pracice he sneconserving moions every dayesecilly efore emping a paricularly srenuous ask. ven high-erformance ahees mus connualy regroove moion paerns daly Some orker groups have aemed o faricae heir own jobspecific raining an pracce equpmen. An examle of his ype of worker pr ofessionalism i s shon n fgue .24 which shows a dummy siing in a wheelchair. Nurses uil he dummy fro m plumbng pipes and use  o prac ce one nd wo-e rsn aien ifs This is par of he worker professionalism ehic noed n he following secion.

Figue 824 Nu rses at a patient care f ac lity abicaed his dm my to practice he paent lfts an example o worke  pofessoasm.

• Ope worke r res breaks. A roerly esigned res rek cn siss of he oposie aciviy and consequenly he opposie lodn) from ha required y he job. For example he sedenaY secrery wll be es served by a dynamic res break he welder on he oher hnd wl be eer served h res and erhas a srech. The followin e ample i llu sra es a voaion of his princile ha cause d rief. ack n he 1960s operaors in a power pln moniored he process fr  chir n had o respon d o a vigilan ce buzzer on heir desk ha en ff e very  minues see figure .25 ab.  each uzzer inerval hey woul sn n walk around he conrol panel makng adjusmens. here s n hisory of back roubles The room recenly became obslee nd s replaced ih an updaed conrol rom. The design eam for he new conrol rom e lieved ha rising from he chir eveY 0 minues was oo srenuous. Consequenly he job was redesigned so ha he oera ors ere able o say seae o erfor l operaions These oerars worke 2hour shifs. Havng he workers s fr his period of ime and removin he ned  ge ou of he chair regularly) resule n an increse in low ack prolems. The power pan hen hired a consuln rou who recommended res reaks ha n sised of havin he worke rs si on n eer cise bike. The workers' backs filed   prove becuse he consulans fai t undersand ha he res break mus no x acerae or replicae he forces of he j n his case sing on a bike ws n  brek from siin on he job

Fgure 825 Te st conto oom a was bl  te 1 960s and req ed he operaor o stad ev ey 1 0 m nutes t o respod to h e vgi ance buzze r ad make an adjusme o e anaog instrmentaon. Thee wee o eported back troubles hs roo m b based o te was epaced wih a new layout desger s' ass umpto tat stadg every 1 0 mn ues was o o strenuos; the opeatos we e able o st o ou rs A hge low back pob lem emeged

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L Back Dsrders

• nvolve workers  the ergonomic processDesn es oen nee o onsl i e exe on  l obe oe o s one i o es Q ie oen e oe nos o   oo soion, n  is s   e o senn n iing e inevenion An e benei soloss  is  o es e oe lel o ol i e inevenon i e eeive eseves o e  jo  o e solon • Design work to be variable As seel eios exes e oene lion o sse sess is e b  ne in ose, loin, o ivi. Hn engs ee no e o eo eeie o  esizes onl  e isses No ee ns esne no o be sesse Rese s eslise  isses  n e oel in eso nse o o eg , bone: e , 1 95 li en: Woo, Goez n Aeson 1 95; is oe,  992; e ee in nn, genn. n He 199 Too lle i n be s obe s oo . Kise n oees een s 2001) sonl einoes e ie so eqenl se n s ex  e obe o goo o esin is no o e ee jo ese in  soe jobs sol e e oe ening o oi el n e Kse s s ens o eoe o b in ee sngse o ose o i no b seel s os. To o ose os ine  ng  o ln oe ges oe n o os e  (seen ) n - e g ong beon eso nl s n sos ies (oo  oing Goo oio nl e  o  sl oseel eseve is eve  eo  in  ve o ss  eesine es vies ong  l o e ion oonens s s oe nion see, voine o son, n so on Desin o o e vie As lse in e eos exes n enes, ngeen s  oe n en  oles n oes  s  se o in  ngeen oes no nee o nesn e siene o s sei in eenion oes As e s eosl nj eenion inolves  oo nesnn o e in sil oess, e  in  goos n es e se vision o oeive eqen, oie ining, e onseion o e osene o nevenon n so o. Tinin o bo oes n ngeen enses e es esls

Injury Prevention Primer To se ioenis o s l oenil in n eenon oes n eoes s ve  esone nesning o e ones s e nesn e o Woes s e ee in e oenl sie niles ese e lie sing exles i  e e il Ae i e genel niles, e n e n o n evise e bes jinonsen segies Te nenion s o enne e nsil oess n enbe oes o ee n goo el Te is o is e e size ee •

First and foremost design work/tasks that facilitate variet.es e

snge os on  giene so  e s Don o oo   n on n o oo  n oo le lon e een  o   n single v  les o oe Relie o  lve isse sins is olse  ose nges o, ee e, oe ss  e ieen soseel ens

Redcng the Rsk at Wok

 8

- While he asks of any os anno  e hange he wokng rounes an arrann o asks whn a  an e esgne sienialy o inororae his rinile omemes i is as easy as onnualy hann he siin os r. •

Durg all loading  avoid a lly exed or bent spine and rotate the trunk using the hips (presering a neutral cuve in the spine).oing his

has h folowing eneis:  s hern iaon  anno ou - Liaens a nno e am age as hey ar  sak.  Th anerio s hearing e fe fro liga en inolemen is mn ze an he osior suoring shear of he musuaure s maxim  Corssie esing of a  oon nis has shown nra ss in oran wih arial exion u erease aiy o wihsan oressie loa a ul lexion. •

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During lifing choose a postre to e the reaction torque on the low back (either stoop or squat or somewhere in between) but keep the external load close to the body.

-  neua sine is sil l ainaine u  soeimes he loa an  ouh ose o he sine wh en knees sua i o relay saih knes (soo lf. The key s o eue he oue ha has een shon o  a omnan sk faor  When exerng fore wh he hans or shou le s y o ire he lne o h oe houh he ow ak. This ill eue he reaon oue an he sine loa rom use onraion. Consider the transmissible vectore o ie exenal fors hough he low ak inimzing he omn ar whih auses hh ous an ush n usle oes Ths rinile shoul e alie when using uln fores hen oenin a oor auuin an eoing ohe househo hoes

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Use techniques that e the actual weight of the load being handled.

The lo-lfin xale gien in hs haer eonsraes ho an nir lo an e if ino h ak o a rk y lifn no or han ha of is egh a any on •

Allow time for the disc nucleus to "equilibrate ligaments to regain stiff ness, and the stress on the annulus to equalize afer prolonged exion (eg, sitting or stooping) and do not imediately perform strenuous exertions

 er oonge siing o  soong sen ie sanin  This nle an e a ae o many seial os   soe wor kers o no hae he lux of eing ale o ak he e o allow h is nuleus o equilia Fo exale aulane ies ar ofn ale on o lif hay os immeialy afe signfian rios of riing.  sray fo h is o us a luar suor in heir sea iing o he nen so ha hir sns are no fexe Thus i an e reare for he oa wih inial is euilirion a o h oess o war u •

Avoid liing or spe bending shortly aer risig from bed

 Foan ing srsses on he s an ligae ns are hihe aftr isin fm e oare wih laer in he ay (a leas one o wo hours fr rising) asin iss o eoe i nju e a loer leels o loa an r o nin.

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ow Back Dsorders

 hs rce s rolemac  or some occaos sch as r egh  h ch orkers are oe arosed rom slee o aed a re ch orkers shold o s  a sloched osre h he se lexed he rave o he scee  raher s rgh I hs a he se l e es reared or sreo ork ho a arm  •

Pestess and stable the spne even dung lght

- Lgh coco rac he sal g mscla e o remove he slac k rom he ssem ad se he se eve drg lgh asks sch as ckg  a ec he exercses sho  chaer 13 ere chose o grove hee moor aers - marg Mld cocorac ad heare cor resodg  creae sal o saeo o maeral o he colm der  axal oad crs e he •

Avod twstng and the smultaneous geneaton of hgh twstng toques

 sg redces he rsc sregh o he dsc a ls  dal o e o  sorg ers hle creasg he sress  he remag ers der load  ce her e s o mscle desged o rodce o axal r e  he colec ve al o he msces o ress axa ore s lmed ad he ma o e le o roec he se  cea osres he addoal comressve rde o he se s ssaa or eve a lo amo o axa ore rodco - Geerag sg ore  h he se sed ma o e a s rlem  ac or s sg lgh ho ssaal ore •

Use momentm when exetng foce to educe the spne load (athe than always lng slowly and smoothly, whch s an l-founded ecommenda ton fo many skled wokes).

 hs s a skl ha som emes eed o e deveoed - hs sraeg s dageos or heav oads ad shold o e sed or l hem - I s ossl e ha a ras er o mome m rom he er rk o he lo d ca sar movg a akardl laced load ho de lo ck volvee •

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Avod polonged sttng.

 Prologed sg s assocaed h ds c herao.  Whe rered o s or log erods adjs osre o e sad    le eve 50 mes exed he se ad/or  ossle alk or a e es. - Orgae ork  o reak   os o rologed sg o shorer erods h are eer oleraed  he se Consde the be�t est beak stateges Csome hs rle or dere o classcaos ad demads - Workers egaged  sedea ork old  e es serv ed  ree  d amc reaks o redce sse sress accmlao  Workers egag ed  d amc ork ma e e er ev ed h loger ad mor resl reaks Povde potectve clothng to foste jontconsevng postuesProvde coveralls or dr maeral hadg heav aros or shar meas kee ad or hose ho ork a grod level ad so o Pactce jont-consevng knematc movement pattens ome orkers ed o cosal regroove moo aers sch as lockg he lmar se he l ad roag ao he hs

Reducng the Rsk at Wk

 83

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Maintain a reasonable level of tness.

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Tese gidelines maybe combined for specia sitations.For examle some

eoe ave iily rolling over n be en eir baks are ainl Nearly all an be ag o manage eir ain an sil aomis i ask by ombning a momenm ranser i e minima isng ieines (see igre 6 a)

Fgue 826 Rol ng ove i bed c an be agh o ose wh o m a nai n a i is oo anl an ac ivy. The fgre l sraes o g om he ef side o he igh Wle yng on oe side,  e aen braces e ors o a so a e se does no wis  e ses ha ollow Te he er ar m and leg are ased ogeher wh e lowe arm an d eg yng off e oor b Ths s eforme d qi cly eogh o geeae momem ha wil carry he aie hogh e ol  Te ae sold ow be resng como ably o is oe sde (d)

A Note for Consul tants Ain as a onslan I ave made many misakes some o  moivae e olong is • Don't fal into te trap of g tat yo are te exper and tat yo know wat is best for te workers nless yo ave done te job for years yorse. Aays ons e orker Sessl ob inmbens ave develoe

ersonal raegies or orkng a asss em in avoing ae an injry eir inigs are e resl o osands o ors o erorming e ask an y an be ve ereve Try o aommoae em • Do not take te instrctions for a specic worker verbatim from te pre ceding Injry Prevention Primernsea exlain e relevan biomeanial rin

ile in angage an erminology a are amiliar o e orker • Do not focs only on te most demanding Given e lnk amon eren asks rom a sse oa erseive yo an oen obain beer solion by onsiering e l omlemen o exosres In a similar vein some onlans en o  os on a si ngle mer o risk o bak omression or examle  or rely on

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ow Back Dsores

nl a f l sins  ava gnis abl  n hav  sciic ainin ncaY  achiv  s slns  l ac ls  ha I a a sinc in cn as I a as  cnl n n cnan l cnciv nc aac av fail I a   bc n vv n  can acs las  h iss a av a h a  ha an lin a nih s n nininal a   ann. Us  In vnin i a a cclis  vala hh nia i f  an  cniv in ah    • Do not focus xclusivly on th musculoskltal issu ni ha  in nancing  insial css An anan a  cni h h f a an/ cnlan h as  c  fficin a h-ali c c h n cnsain css. c •

Finay nvr mak a rcommndation that is not fasil to implmnt

h  naY  an h ans.

References Aaras, A ( 994) Th impat of ergonomic ntntion on indviual halh an crporat prosperiy n a tlcommuncations nvironmnt E1onomics, 37 0): 1679-1696 Adams, MA, and Huton W (191) h rlvan of torson to h mchania drangmn f th mbar spine Spine, 6 24124 Autir M, Loti, M, and Ganon M.  199 6) anual handlin thnqus: Compang nvs an xprts lneafonajow'na q/ldustria Ergonoics 17: 4 9-4 29. Balwn, ML , John son, WG, an Bttr R . 996) Th  of sing rtustowork  masr th ocoms of health car A ricanjoua Indusa MediCne 29 6): 632-64 erngSorensn,  194) Physial masrmnts as risk ndicatrs for ow-bak rub over a onya pr pne 9 106-119 Brinkmann P, Bigmann, M an Hlweg, D ( 199) Prtion o th mpssiv srngh  human lmba rtbra iica Biomchaics 4 (Sppl 2) 27 But AF. Khan, M, Ellio, B.C Fosr DH arshal, N an arasl  ( 9 ) h raolmbar ds egnraton in young fas bowrs n rik A follp sudy ca Bchanics 1 1 : 305-310 Burstn, A., and Frankl, W. 96) h vsoeasc proprts of som blogal matral A  as /N York Acady ocinc 146: 15-165. Cay D shof, P. O'Conn, . hmas, P, an Allan,  7) Srngth an fnss an sbsnt ak injuris of fifihters jou a q/ Occaio na Mdicn    6 . Callaghan, J, an McGl, SM (001) o bak jint laing an kinemas uring snng an nsupp sitin onomics 44 (3 ) 20-294. Calaghan, , and MGil SM 2001b) Inevrbral dis hrnation. Stds n a porin ml xpos to hhy rptitiv lexn/xtenson motion wit omprssiv forc c Bo chanics. 1 6 0): -37 Carr, D 9) Bomhanics of bn In Nahm, ., and Mlvin, J (ds) Bochics q/ ma rwalk C Appeton Cnury Crofts Chl wik ,  ulr K. , an Gll SM. 1999) Th intraabomna pssr mhansms for sab lizing th mbar spn jou a oBomchanics 3: 13-17 Faran, H F Cosstt ]W, obtsn, GH , Wlls, RY  an d Kras, l  970) Th efs of rsn on he l mba  nt bra" join ts Th ro o to son in h prodcon f dsc gnratn J a oBoe and jn  rge 2A (3): 469497 Farmr, M, Lok B.Z osciki, K. Dannnbrg, A arsn DB, an adloff S. 9) Physical atvity an  dprs sv sympto ms h HAS [ pidmlg fo lwup study Aca joa q/pdeiooy 12 30131 Frank  W Brookr A.  DeMaio , S .   a1. 96) isabity resing fro m upainal  3P Par  Wha  w know about senda prevntion? A rv of h sin vin on prvn n aftr dsabit bgns p 21 : 291 -29 7.

Redcng he Rsk a Work

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T 983 myer, JW, Pe, MH, lements, J, Wlder, G MacPhersn, , and Ashkg Rsk factrs n l bck an joun a oBon and jont uy 65A: 213-2. Garg, A , a nd Herrn, G  ( 1 979) St p r sq uat A bmec hanca l and metabl c evalutn can Inttut /nduta nn Tnacton1 1  293-3 02 Bochanc Grieve W (975 ynamc characteristics f mn durng cruch and stp fting v eds esn , and Mrehuse, A  1929) Baltimre nversty Park Press Hamltn, W, Wdbury, A, and Harer, H 1944 Arterial, cerebrsna and venus res sures n man durng cuh and stran canjouna oPhoo 4 1: 42-0  Hasam, , Mcartney N, McKelve, R, and Macugall,  9 Drec measuements f artera jou a 0 adoponay bd ressure during frmal weht lfng n cardac patients Rhabtaton : 23-225 Pvnt Huhes JR ( 194) Psychlcal e ffects f habtual aerbc exercse A crtcal rev Mdcn 3: 66-7 Jacksn, M , l mn, M , Zhu, B  aratta, R, and Harrs, M  2001 ) Multfdus  MG and tensn-relaxatn recve after prlnged statc lumbar flexn pn 26 7): 71 -7 23 Knney E, laghn, J and McGll, M 996 Lumbar sne mvement nd muscle actvty usng the gfer's lftng technque In vdnc bad Eonoc 28" Annua nfernc e f the Human Factrs Asscatn f anada, Ktchener,  73-78 Krause,  Dasnger, LK and Neubrauser F 99) Mdfed wrk and return t rk A reve f the lterature joa / Occupatona Rhabtaton   2) 1 13-3 9 T  and Watzdrf, M Krsmer, M, Trbs, S, anna, , Sllner, W, chnthaler, , Auckenthaler, (2001) Prevalence and risk factrs f l back an in schl chldren A crss sectna study In btact Internatnal Scety fr tudy f the Lumbar Spne, Edinburgh, Sctand Lntn, S , an d van Tuld er, M W  2001 ) Preventatve nterventins fr neck and back an rb  ems pn 26 (7): 778-77 Lse, P Abenham, L urand, P. Esdale, JM Suissa, , Gsselin L, mard, , Turctte,} nd n, emare, J (  997) A ulatin -ased, rand mzed cncal tral n ack an mnagment 22 24): 2 9 -291  Lut  Helra ara, M, Hurr, H and Alavan ta, M . ( 1995) Satc bac k enduran c and he rsk f l back an nca ochanc, 10: 323-3 24

Macugall  uxen , Sale, , Mrz, J and uttn, J 95 Arteral bld ressure re snse n heavy resstance exercse jna 0ppd Phoo 5 3 78-79 T ( 1984) Relatinshp  etween the chnges n hear rate Mantysaar, M, Antla, K, and Peltnen, and crdac utut durng the valsava maneuver. cta Pooca candnavca, Su, 537 4-49 McGll ,  M  1997) mechancs  f l back n ury I micatns n current ract c nd th lnc oa /Bochanc 30 5: 465-475 McGl, M and rn,  992 reep resnse f the lumbar spne t rlnged umbr len nca Bochanc, 7: 4346 McGl SM, Grener, , Preuss, R, and Brn,  (n ress Psychphysca, ersnal nd me chanca seuellae t w back pan McG l , S M , an d Hdl ess, K 990) Measue d and mdelle d statc and dynam c a trunk trs n durng tstng n males and femaes joua / Bodca nnn 2: 403-49. McGl l  .M , a nd Kers, V ( 994) ran sfer f lads between umbar tssues durng the le n relaatn henmenn pn 19  19 2 190 -2196  McGl, SM, and rman, W  1 985 ynamc ally and static ally de termn ed  back mm ents durng lftng jou a /ochanc 8 (12 77885 McG l,  M , and rman, RW  987) Effe cts f an anatmically detaed ere ctr s ne mdl n L4/5 dsc cmressn and shear joua 0Bochanc 20 6 591-600 nca tho achemsn, AL 966 he lad n lumbar dscs n dfferen pstins f the bdy padc and Ratd Rach4: 107-122 Ppe, MH, anley, EN, Matteri, RE, Wlder, G, and ymyer, W 977 Measuement f ntervertebral dsc sace heiht pn 2: 282-286 Prter, RW ( 1 992) Is hard rk gd fr the back ? The relatnship beteen hard r k and lw back an-related dsrders ntatona jouna 0Induta onoc9: ] 7-6 Pvin , J rman , RW, and McGl,   99  Reductin n anter ir sh ear frces n the L4/L d sc by the umbar muscuture nca ochanc 6 96

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ow Back Dsorders

Ritn M   4  On th o nt of li ini th  rropinl p Acta Rado cand 22 762-77. A can Ro C.E. n Hy D. ( Exri n pyhooi wl-in in th onity jouna opdoo27: 762 -77  Snn ll ].  n MGill S. M. in pr  Elt qil ibri of th lr  pin Shlt, A B  Wrwik, D.N ., rk on M H.  n Nhon , A (  7 Mh n pr oprti of th  hn lr pin otion  nt. Prt  : Rpon to fl xion xtnion trl n in n torion. jouna oochanca ngn ng 0 : 46-52  Shiri-Al A. A h A. M.  n Shrit  S.. ( 6 Mhn l rpon of  br  otion nt in xil torq lon n on with oprion. pn   (: 4- 27 Snook  S .H . Wbr  .S . MG R.W. Foln M.T., n MCnn .B  ( 8 Th  r ion of hroni nonpifi low k pin throh th ontrol of rly ornn lbr xion: A rnoiz ontroll ril. pn 23 (23: 260-2607. Sni, ]H Oj P., Miilnplo S. Pnn, ME., Vori .M. o,  8 Hlthrt fit tt try for lt: Aotion wih pri hlth oility, n bk funtion n yp t. A chs �Phca dcn an d Rhaaon , 7(5: 55-56 Trop ]D .G . n Chpn A . . ( 6 Th trnth of h xor n xtno r m o th trnk. jouna  ochanc 2: 4-62. Trop ]. . G  77 Dyn f tor i n h nyi of toop n ro h l ftin  tho: A tho ooil pproh to th lopnt of f tri hnlin tnr. Ohop. n NA 8 ( 20-20 rop D G  Mrtin ]W n Loy DC. (   k pin in intry A propti r y pn 6: 66 Twoy 1., n Tylor ] . (  2  Flxion rp fortion n hytri in th lbr rt brl oln pn 7: 622 Uno . n L Y. 7 A hr-nionl nonlinr finit lnt ol of lbr intr rtbrl oint n toron jouna  ochanca ngnng 0: 20020 V n T., Nrinn M  n r op ].0. 0 Lr pinl pholoy in r tril in rltion t hiory of k pin opion n phyi oin. pn 5: 728-740 Wilr D .G . Pop M H.  n Fryo yr ]W.  8 h bio hni o f lbr i hiton n th fft of orlo n intblity jouna opna Dsod  632 Winkl ]  n Wr R H  ( 6 tor l  A o f or oln w ork rlt lo kltl pl in  profitl wy Appd gonoC27: 7-7 Woo S.L.- Goz M.A. n Aon, W.H. (5 Mhnl hior of oft ti: Mr n oifi tion injr  n tr tn t. I n: N h H M.  n M in ] ( ., ochan cs aua pp 0-33 Norwk C: Appton Cntry Crot. on  R  7  Th fft of rlr xr on onit fnionin n pronliy. sh jouna opot dcnSptr 3 (3 :  0- 7

Reducing the Risk in Athletes: Guidelines T

i catr alie t ame scientificaly tifale elines tln  in catr t rc  ri  ac trbl, al tis cater arsss altic sitatin Atletes an teams rm a variety f srtn activitesrm wrl-class rfesnal  amatersave t my avce a a lw ac injy cnstan n many cae tir ba ac were enin er carrs B as we ave seen i n rece

in caters, cc n eain w ba bacs reqires ef t ars t t ca f t trbe an te mt arra raitative eray. n many cas, arsn t ca meant tat atletes a t cane teir ecni Witt  cetin ey a t cane e way ey trane Smeimes tis rese in small ecrements in teir erfrmances,  tese tecnqe canes enable em  re man cmetitve an financialy reware e aleic acivie f t many ale  ave wr wit ave varie frm team rts, sc as aseball cy, ba ball an ftball,  nvia srts sc as f n cmtin f ts caer y will e ale t rmat cinifically base ieline tat rece te ris f lw ac trles n alee

Reducing the Risk in Athletes Te eam cntaine n te fllwn sectins ltrate w bimecancal rin cile can be alie efectively t virtaly any rt Te ling etin are en ase abt w  miniize aletic ac rles. e answr sl be e as a ceclit t eermine te mt effecive arac  rce t irritant f a eciic atee ac trles • Should athetes avoid end range of spine motion during exertion? Gner ally te anwer s yesi te sn bective allws r ts sray n revi caters  cmne e many cmicatins tat arise rm tang e lmbar ine t e en rane  mtn n any acviy Alec tass ften ave te ai tinal rer cae y i ratnal vecite in te sine, wic fen rce te aiv tss t erence mlive lain a tey act  creae t mcanical

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Lat bend = 6 deg Max ROM  35 deg

La bend  0 deg Max ROM 4 deg

= 

o

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La bend  5 deg Max ROM  4 deg

20 Twist

30

Flexin  33 deg Max ROM  63 deg

-40

b Fur 

20

40

60

80

00

20

40

Fames

Ths basebal catcher's ow back was oubed, n paricuar, by isng ou of the couch and thowng the bal to second base to dea wth a runne steaing secod base. Documentato o he lumba nematcs reveaed arge excursos n exion exeso axs In act, he lumbar spine was exended to ts full ange o moton and flexed o eachig abdomina bacig ogether with spie position ad motio awaeness educed the range of lumbar moion to n exeso ad i flexo As a result, he symptoms essened



(a).

°

35°

33°

b

s tathlets mtinsns: Fllwn ar exams n whih techniue change has salva sm  A baseba l atcher was eeiencng ebilitatin sn tu les whn risng f m he cruh an thrwin the al  aress unners saing scn ase A cminatn f abminal bacin an earnng a sn inemati mtn fil ha reu he sine range  mn hel grealy (s figur 9.1 ab h ahlte's thrwng see was cmmis t a smal r bu th athet maine meitive.  Glfers tyicaly tae thir snes hru h ful ranes  mtin in the laal ben an axial twist axes n an aml fm a rfessnal gfr th sn rah

Reucing the Rik in Athlete: Guielne

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Tme

Fur  s pofssoa go srd coic dbliag o back roubs ad sogh or xps Th ubar kac aaysis of  sg vad a h spi as ak o  00% o h aral bdg capaby ad 6% o  s capaby i ac sho.  oly ay o lp is back as o ov  cas-a s rdc his oio Rraig  abdoas o brac ad ducg  backsg rdcd  sypos

100  te lateal ben caabity an 96  te twitng caability Ti ne brtality wa errme wt eac wing  te g b-at leat 200-300 time e ay ee wa itte e  ecvey wtt ecing t laing Te nea ng a ac wa t rece te bacwng an grve abmnal ba ing atten tat lce te ib cage t te elv n te lwtg Sine range  mtn wa i mini e ( ee ige 9 . T gle t a ew yar m te bal  tance ring a maim m rve et bt a  ena ge  ay a game  accate ba acement ti ectin ae n cman t te i blity  ling te caability t lay at a ig level  cmettin e reactin • How do you use technque to reduce the recton moment? mment abt te w bac elt rm te ale rce vectr an te erenc lar itance m te ce t te lmbar ine A maller eactin mment relt in we intenal tie la neceary t t te mment ti are te ine Generaly wever n rtng actvtie a rece rce i neirable Te bette tn  t ece te eve am  te ee nc lar itance  te eternal  rce t te lc m n te lw bac (ee  66 Maria ait tae avantage  ti tec nie, a  tball lineme n iectng t e etenal ce vectr trg te lmba ne tee rce mment angre te re ltin gmnimize cmreiv ( ee 9.3 . Te eternal rce i till ig  mai mm emance, bt te a n te ne ae minimie

Fur 

his oobal playr  apg o ackl h ba carrir is dvlopig g sp loads as h had ocs a o dicd hrog h o back Graly b cqu s o dic h focs hough h lo back l appyg sabzig orcs o  oppo

• Is there  probem wth proonged sttng on the bench? Recal tat r

lnge en eacerbate cgenc bac trble tgeter wt igament-bae yn me e tin  mt atete wen itting n te benc relt in lng

'0

Low Back Dsorders

fll lmbar lexin see fige 4a). he sine tes ate by me f the tall baketall layer ar tagicaly cmical Sring traiin ictates thi sr even thgh it is s etimental t many tlem bak cntins w   n ier ab enhitting are a fllw  Simly havng athlts with back rbls in articlar is geni bak i rers, n it n th benh n th way es their ymms. me in eief rm taning an acing while ther fin relief fm ting n hair with n elvt seat n that s anglate a t minimize sine lxin (figre .4b  Fr yar hysilgits have shwn th msc uar valar an ventiat ry hang  fm warmng  Wam aft sne mechanc t A n ty  ment the increae sne mliane n a hr f vaity vlyba layer Grn Grenier an McGill, in ress) fllwing a warm- After ting n th benh r 0 mintes hwever his miane was lt wenty minte i a tycal stting tme fr vlleyball layr an fr athtes n many ther rt s wl)  he lating eff ect f the warm- is  it ht-ive if atviy i intrrut with restariclaly sea ret Paye shl reae thr bks flwing a rlnge eri f sea rest. Agan this nles itting n high hirs n staning an metimes aing ir t esuming lay. • Shoud ahees rain shory aer risg from bed? h answ is nif a larg amunt f lmbar mn is rre. Rearche have mnte the in ca ann ress after a bt f  es In artilar fll benng exris ar ntrainicate et many athlets an ayee alik get  in the mrning an erfm sin e stetche  tu an  n hi is the mt angr time f th ay t netk sh activiti It is anar athleti re f rwer r xml  ri veY ary an train n he water snce th war i cam this time f ay wing ires large amnt  sine exin ing the atch hase We hav ha t train rwers with is atearlymrning a techne stategy avis fll wl lmbrblx in  Rwers ay rbles early fr heir at waterhat their bak mh bett serv by training late in the ay.

Figure 

(

tig n the benc wt a flexed ubar sie is beatic  tw eass:is stue creates ad/r exacebates a sterir dsc buge ad t causes lss f te clace baied  waig u te back tg in taer chars with an anguated sea an educes luba flexn and the assciated cces

b

ecig e is  Atlees: Gieies

191

• Shud athete breathe during a particuar phae in the exertin? any emmen that athlete exhale when raiing a weightor the opite W hear fo examle that when perfring the benh re exeie one hol exhale pon the exertin. What eviene i thi bae n? hi pattern wil not tranfer to the athleti itatin in a way that wil enre fiient pin e tability A I emhaize in hapte 6 on tability the gooving of tranerable tabilizing oto attern reqie that lng ventilatin bee inepenent of exertion he ine mt be tabilize egarle o whethe the in ivial i inhal ing o exhalin g We reomen that the athlete train to beathe ineenently of the exetion he rare exetion may be fr the netie maxim effort that reqire eme ine tifne for a bie pei (o exame

weightliting opeflly thi wol be a rare oene o ot athlete in training • Shud athete wear abdminal belt during training? Eviene gget that eope hange their motor attern when ing a bet In a ty examining baggage haner (wrker wh la an nloa airpane) Reel an lleage 2 nte ineae inj ate in the wh were frer belt weare bt ha then te Ganata Marra an avi 7) ne gro tehniqe hang when ee wore bet. Many aot bet in training fr ne of three reaon - Thy have oberv e other wearing them an have ae that it wil b e a go iea for them to o   Their bak are being ore an they believe that a bak belt will hel  They wan t to ift a few e on one  thee eao n ae onitent with either the literate or the b jeti ve  go health f ne mt lit a few e pon wear a belt. If one want t grve mtor pattern to tain fo other athleti tak that ean a table toro it i rbably better not t wear one. Chater 0 oer a thorogh iion of the reearh that rt thi reommenation

• Shud the trnk mucuature be ccntracted t tabie the pine? The anwer i generally ye. Many atheti tehniqe reqie e tabiization t me efetively tanmit fore throghot the boy egent hain Stiffening the tro i taght for any tak Thi apoah al ee the rik o low bak injy The tima aont of tiffening een on the tak. Lager amnt of tine a n be neee in the fllowing ituation  When the athlete ight exeriene nexpete loaing a in ontat ort - When obination o imlt aneo moment an applie  oe evelo  a in a baketball layer etting a ot - Ater pee an aeleation f bo y egent are eqie a in a golf wing r elivering a bow in artial art • I peccity f practice regimen imprtant fr w back? Sine-aring kinemati atten an tabilizing otor attern nee to be pratie an gve int moveent reperie Sine ratie make emanent it i rial that rtine

one atie repliate a lely a ibe the eane by theinort o on't want the permanent" yomoveent ahieve tan be kill inrret Ak fr examle wil an exerie with free weight or an exeie mahine that ilate a boy a better eliate the nition  the pot tak? I tength realy the priary eqirement for a partiar tak  pine ange o otion a reqiremnt or oe the athleti tak at han eqire a tif pine to tanmit ore fm the er boy throgh to the leg an to the gron? Eve athlete an oah mt xamine  have the reqirement an bjetive  their erformane tak Time an again

192

Low Bak Diorder

seen rining h nc lue bjec ives n require by he lee riculr even   grely cmrmise sine helh Fr exme, recenly in Engln Prfessr Fre en simule  sme gymnscs mves n he n increse vriu s cmnens f finess  see f erfrmnce ws enhnce r sme umbng n smersul sks incresing sreng i n el rher keff see ws he cmnen h en be mre rns n he r nftunely e rnciles f bybuing ve enere rining fr s mny hlees leing sme  rin  lk g rer n  fcus n regmens rece slely  enncng erfrmnce. e n inn gin rch is he msrece nemess f mny  b bck Remember  srng sne in sn my n necessry be  sble sne. A sble sne minin wih hehy n wise mr erns n hgher muscle enurnce recs gins bck rubles n generly enhnces erfmnce • Ca imager hep protect ow backs? he ses in using mgery fr evel II. ng bck-sring erns fr bh erfrmnce n hel re lse in cer Wile hese re fr sne sin wreness n grving mr erns ey c be vey hel  hees.

What Coaches Need to Know Mny hees bcks re ruine in riningn in cmein. his smemes r sls frm he circumsnces h re rinl  he sr crumsnces  mus be cnge. A g exmle cmes frm Ausrl where cricke bwers yiclly evee rs frcures Afer scenfic reserch clrifie e mecnsm f njury legslin ws evee  nw ces he mximum number f bwls  crcke bwer cn erfrm in  cetin eri Aleic rern by s vey nure requres verl which is cuner  rin ng fr heh becives As such i exses hlees  mre rsk. When cces  bybu ilng regimens  heir hees rgrm s hey cn furhe r ncrese he rsk  eir lees Cches re well vse  efine cery he rning ucme bjec ives n esign  rining rgrm  in hem in  wy h sres he bck n her ns. he rcess f eveling  sble cre escrbe in cers 3 n 4 s esgne  sre he sine. A bcknure hee s n chnce fr succss. Cches wh sk me  rve rining rgrms fr her hlees n ems re fen mze  fin h  cnn  s wiu  enerng nlyss f e invu(s) n he sksecifc becives Oml rern f n hlee is n ceve by fling  ckbk recie eveY hlee n even r sr is ifferen Even he exers hve  cninully imrve eir skill n rcce  mly rere  ifferen hlees 

References Granata K.P, Marras WS. and Davis KG. 97) Biomechanial assessment of lifting dynamis usle ativty and spinal loads while usin 1ee dierent sye liftin bets Clinical Bimehanics 12 (2): 107-15. Green ]GrenierS. and MGill SM (in press) Lo bak stifness is aered with waru and benh rest: Impliations for athetes Reddell CR. Congleton  Hhinson R and Monomery ]F 992) An evaluaion of a weihtlitin belt and bak injury prevention trainin lass or airline baggage handlers Applid Ergonomic, 23 5) 319-329 

Te Question of Back Belts

(

hp  ddeed he ue of el for hlec endevor. Thi hr wil ous on occuponl el ue ee fure 0 -c for h ypil yp f l  nd eed. Afer edin hi chp you wll   o ke deciion on ho houl wer  el nd o uify he uideine o he precripon nd e

Figue 

Sevea ypes of belts are won and have been tested: a the eathe belt, b the infatabe ce bet ad (c) the stretch be wih suspendes ae a few exampes.

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Low Back Dsorrs

Issues of the Back Belt Question The aveae paie mu e oued when he oeve oh Olympi ahlee and a-injued people wean adominal el Seveal yea ao  ondue a vie of he efe of el weai MGll, 1993) ad ummazed my finding a follow •

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Thoe who have neve had a peviou a ijuy appea o have no addiioa poeive eefi fom wean a el. I would appea ha hoe who wee injued while eaig a el i a moe evee i Be appea ive people he peepion hey an lf moe and ay i fa enae hem oolif moe el appea o eae ia-adomial peue ad lood peue Bel appea o hane he lifin yle of ome people o ehe deeae he load on he pne o eae he load on he pie

n ummay ive he ae and liaiie of el weai, I do no eomend he fo healhy idividual ehe in oune wo o exeie paiipaio Hoeve, he emoay pepion of el may help ome indvdual woe eun o o Manufaue of adomial el ad luma uppo onue o el hem o induy i he aee of a euaoy equieme o odu onolld linia ial imila o hoe euied of du ad ohe media devie. Many laim have een made a o how adomial el ould edue injuy o exampe ome have ug eed ha el pefom he followin funio: •

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emid people o lif popely SUpp hea loadi on he pie ha eu fom he effe of avy ai on he hadhed load ad ma of he uppe ody when he u i flexed edue ompeive loadi of he um a pine houh he hydauli aio of ieaed ia-adominal peue aoaed wih el weain A a a pln edui he ae of moo ad heey deeai he i of inju Povide wamh o he luma eion Enhane popioepion via peue o ieae he peepion of ailiy edue muula faiue

Thee idea amo ohe wl e addeed in hi hape The foli eion addee he iee eadi he oupaional ue of el and onude wih evidee-aed uidelne. The 994 OSH epo, Woplae e of Ba Bel" onaied iial evie of a uanial nume of ienifi epo evaluai a el The eo o lude ha a el do no peven injuie amo unued we no ae hey poeive foaed hoe i who have een nued. hipeio i eneally ie wih ou poio 1993 myo peonal poiionWhile on el  omewha moe modeae

Scientific Studies I he followi eo  have udivided he enfi udie no lnial ial and hoe ha examined iomehanial pyhophyial ad phyioloial hange fm

Te Qeo of ak el

195

l wring inlly, d on h vidn, I rommnd idlins fr h prsrip ion nd s of l in indry

 T Mny lini rils rpord in h lirr r frgh wih mhdlgil pr lm nd ffrd from h n of  mhd onrol rop no psril fol p imid ri drion, nd inufin mp i A  r, I il rvi nly  fw linil ris in hi hpr whil nowldin h xrm diffly in x ing h rils Walsh and Schwartz 0 dividd  m wrhos wrrs in hr grop  A on go p  27) - A p h  rivd  hlf hor rining sion on li fing mhnis  = 27)  A grp h ri vd  on-hor rining sion n d or   rhos s whil  or for h un ix monh  27) Ind of ing mr ommon yp of dminl l hi rrh grp sd orhos wih hrd p h wr h modd o h ow  rgion of h individl Givn h onrn h  rin w hypohizd o  h dominl  n, h rrhrs mrd h dominl flxion srnh f h worr s oh fo  nd fr h i nil ril. h onol g op n d h rinin only grp shod no hng in dominl lxor rngh, nor ny hng n os im from or h hird rop hih rivd rinin nd wor h s sh no hng in domin xor rngh r idn r u did sho  rs n o im vr h inrd nfi pprd only o r  hs wrrs •

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ho hd  prvios in irin y. Vn Popplhndlr. nd ol  ( 199) rhd  imilr onsion in  lo dy of 312 ggg Reddell and colleaes 2 did 642 ggg hndr h rd for  mjor irlin. hy dividd h gg hndlr ino for rmn grps - A onrl gr p  248) - A grop h rivd only  l   57)  A grp h  riv d only  onhou  dion si n  = 122) - A rp h  rivd oh   nd  on-hor dion sin n 57 h ril d igh monh nd h l d ws  f ri wih ifing l 15 m (6 in id posrirly nd pproximy 10 m (4 in.) id nriorly. h rsrhrs nod no ignifin diffrn mong rmn rop for ol mr inj  ini dn r ls wordy, or worr  ompnion r  Ahogh h l  f mpi n y  ignifin nmr of  in h xprnl grop s  fr onidrin h h n wring ls  disnind hir  hd  highr lo-dy  inj inidn r In f 5% of worr onging  h l-r •

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in grps disnind wrin  for h nd of h ighmnh ril rhr, n inrs in h nmr nd vriy of lmr injuri orrd fllwing h ril in ho ho prviosly wor l Mitchell and colleaes 4 ndd  rropiv dy dminird o 36 rrs ho prformd lifing ivii in h miiy Whi his sdy rlid on slfrprd phyil xpor nd injry d ovr six yrs prior  h dy h hrs did no h h o of  injri h orrd hil r in  l r nilly hihr hn h o of injri ind hil no wrin  l •

196

ow Back Dsorders

Kau and coeage (1996), n  wdly prd udy uvyd  lw bk nury   nrly 36000 py   H Dp sr in Clrni  989 t 199 Duin i udy pd h pny plnd  ny bk b u piy Injuy r wr rrdd. Evn u  u i h bl wrin rdud h inidn  lw k injuy nlyi  h d n h lgy u   uh r uiu nrprn y b wrnd. T d hw  w l win rdud h rk in yun l n h ld n  y l wn ppd  increase  k  lw k nuy r n wrking ng hn u yr y 2% huh h l ndn nv  qud n vn lr inr   nn) nd n n wkin l n n yr Hwvr   nrn  h k  in nl  r u  ru l-wrin  r w n pbl nnb-wn grup wh i i vn h  wrin piy w n h l inrvnn  H Dp. Fr pl v h prid   udy h pny nrd h u  pls nd rki nslld  r hir pnd pdn dug in n nhnd wk nn In   niu p w d  nhn y n  rpr ulur. T w  rg udy nd h ur g rv d r h v d rdun nd  Hwvr spi h  nd l   bk  du lw k injU is unnlld uy nn nwr h qun u h ivn  b Wae and coeage 2000 in pn   u pn  h Kru  l. ( 1996 ppr y  nr rup nd h sudy hd i nns rplid Ku nd wrkr wk undr h spnhp  NIOH Th  r hwv ud r in n in d  vlu nly    h ls Suvyn vr 1383 ply  nwly pnd s   jr ilr n wi 89  rquird py  wr  nd  r hd nly vlun us h y dvd h   b  il  rdu   nidn  b k nju y lis •

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T udy h  pwr n  Kru dy n u diuli  uin   lnl r r knwldg. Th Hwhrn   i  nn   i diiu  prn  ru dublblind pdig  wkrs sin  wh riv l inly knw . In ddin lis nsins n urin divry in up n nd pl z r pl Hwvr  h  rpr in h ·ud linil i nn Upp  nin  unvr pripn  l   ll wrkr  nvlvd n nul hndling    u  rik  wbk inuy. Wk vidn ug  hs rdy njud y bn  bl r dd rh) w  rdud rik  nury urn Hwv vidn d n ppr  upp unnjurd wrk wring bl  ru h risk  n; in   rk  n   in during h pri ling  r   wrn. Fnlly  vdn ugg  h s   bk inury y b igh n wk w w b n n wrkr wh  n.

h S r wh v sud  bin us   wring hv ud n pinl  nbdin prur AP, d nd rng  in. T s inv ud r rviw in  in

lAP and Lo w Back Compre ssive Load hnl udi v ind hn s in lw k kini n psur in iin  us  pi iu ln Tw udi n pulr (Hn  . 99 nd Lnd Hunly n Sinn 1992 ugd  wn n binl

he Quesion o Bak Bes

197

e an ineae he an of afey duin epeive lin Boh of hee pape epoe ound eaion  oe and eaued i na-ado na l peue whe uje epeaedly ifed ael Boh epo oeved an ineae n ina-adoinal pe ue in uje who woe adonal e hee eeahe aued ha na adona peue  a ood indao o pnal foe whh i hihly oneniu Nonehe, hey aued he hihe eodin of ina-adoinal peue in aed an ineae n ow a uppo ha in hei vew juiied he ue o el. Neihe udy eaued o auaed pnal load. Sevea ude have queioned he hypoheied n eween eevae na adoina peue and eduon in ow a oad Fo eaple uin an anayal ode and daa lleed fo hee ue lifn vaiou aniude o a MGl and oan 987 noed ha a uildup of ina-adona peue equie aiional aivaion of he uuaue n he adonal wal, eun in a ne ineae in low a opeive load and no a ne eduion o loa a eeah  ha peviouly houh n addion, Naheon and oleaue 986 pulihe e epeienal eul ha diey eaued inadal peue duin he p foane of Valava aneuve douenin ha an neae in naadonal peue neaed, no eeaed, he ow a opeive oad Thefe he onluion ha an ineae n inaadonal peue due o el wean edu opeive oad on he pne ee eoneou n fa uh an ina ay have no ee o ay even ineae he load on he pine

lAP and Low Back Muses Seveal ude have pu o e he elie ha AP afe low a eeno aivy MGil and olleague 990 eained ina-adoina peue and yoelei aiviy in he un uulaue while i ale ue pefoe vaou yp f lif ihe wean o no weain an adoinal el a eh el wih lua uppo ay Velo a fo inhn and upende fo when uje we no lifin Weain he el n<eae inaadonal peue y appoiaey 20%. uh he auho hypoheied ha if e wee ale o help pp oe of he low a eeno oen one woud epe o eaue a eduion in een ule aivy Thee wa no hane in aivaon lve of he ow a eno no n any o he adonal ule eu adoini o olique In a udy ha eaind he efe o e on ue funion eyna an l leaue 995) eaned 22 ue fo ioei low a eeno engh an fun e pvide no enhaneen o unon ahough hi uy wa ny a fou-day ial and did no eane he effe ove a one duaion Ciielo and Snoo 995) eaned 3 en ove a ou-wee peo fing 29 ei nne n fou hou wie a wee oh wih and wihou a el Median  quen of h ow a e leoyoaph nal whi h i enive o loal u l faiue wee no odifed y he peene o aene of a a l enhning h noin ha l o no niianly a lleviae he loadn o a eeno ue One aain, h ial wa no ondued ove a veY lon peod of e

Belts and Range-oj-Motion Restriction n 1986 an an Shul oeve h neai ane of lua oion in uje wean low a ohoe  While  hy udied o e and ae ahe han ai nal , hey dd epo eion n he ane of oon alhouh he e mn wa inia in he eion plane In anohe udy MG l  S eun and Benne 99 4 eed ei ili y and f ne f he lua oo of 20 ae an 5 ae aul uje, oh whe hey we and

198

Low Bak D soers

i nt wear a 10-cm (n) eaher aominal bel The sffness of the so was sgnifcantly increase aut he lateral en an aial twst aes wih wearin belts bu not when subjecs were rate into l eon Thus, these suies seem to incae hat aomina elts hel restrict the range f mtin about the lteral en n aial twist aes bu o not have the same effect when the trs is frce in ein as n an inusrial liftin siuatin. Psure f the lumbar sine is an mporant issue n inury reventn fr several reasns. In arti cular Aams an Hu ttn  1988 showe th a the compressve strength of he umbar spine ecreases when peope aproach the en rane f mtn in fein Therefore f belts restrct the en rane of motion, ne woul eect the risk f nj to e crresoningly ecrease While the spining an stiffening ctin f elts ccurs aout the atera ben an aal twist aes, stiffenin about he flein/ etension ais ears to e less A mre recent a t set presente by Granata, Marras an avs  997 surs th e ntin tht some elt syles are better in siffenn the tors in the manner escre previusynamely, the taler elastic elts hat san the pelvis  the rib cage urther mre these auhrs aso cumente that a rg rhopeic bet eneraly increase he fin moment while the elasc elt eneraly reuce sinal a Nevertheess he uthors ne a we varety in suject resnse. Sme subjects eerience increase sinl laing with the eastic et) Even in wellcnrolle suies bes aear t mouate lfin mechanics n some sive ways in some ele an n  netve ways n hers.

S f , H     unter an cleagues 989 mnitre the bo pressure an hear re f fve males an one female erformng ea s an one-arm bench resses an riin bicycles wearn an not wearin a 10-cm weigh elt Subjcs requre while to hol in a liftn postue a oa f 0%n) f their maimum weighwere in the ea ft for tw minutes The subjecs were reuire to reathe thrughu the ura tin s that no Valsava effect ccurre. During the liftin eercise bloo ressure u to 1 mm) an heart rate were both ignficanty hiher in subects werng belts Given the relaionsh beween eevae systlic oo pressure n an increse risk of strke, unte an cllea ues ( 989 conclu e that in iviu ls wh my have carivascular system cmprmise are probably a reaer risk when unertaking eerse while wearng ack surs than when nt wearing them Subsequent wrk cnucte in u own abora ( Rafacz an McG l, 996  nves igate the o ressure f 20 young men erforming seentary an veY mil actvites boh wih an wthut a belt The belt was the elasic type wth susenrs an Vecr tabs for cinching a he front) Wearn this tye f nusrial back elt gnificantly increase astolic b ressure urn quie sitting an staning both wth n withu a hanhe weight uin a runk rottn task an uring a su liftng task. vence increasingly sugests hat belts increase boo ressure! Over the past ecae  have been aske o elver lectures n partcte in aca emic eae n he ck belt ssue On several occasins ccupatonl ecn persnnel have aroache me after hearing the effects f belts on bl ressure an intra -aominal ressure an hve epresse suspic ions that longterm belt we r ng a ther particuar wrkace may possbly be inke with hher ncients f varcse vens in he tesicles hemrrhis an hernias. As f his writing there has been n scentific an sysemaic invesigatn f the valiity of these suggestions Rather than wait fr strong scientific ata to either len suport to these ieas r ismiss them it may be pruent  simply state concern. Ths will mtivate stues in

The Qetion of ak elt

99

e fuu o ck e incience n prvlence of ese pessurrele irr  ses we ey r inee linke o bel rin

yhhy S So v expesse concern  in  els fo e n inr sens of iy  y or y n o be rr ne Suie be on e psycop ysic pri llo orkers o selec wis  ey cn lif repeey usin eir own ubje ive preions of pysicl exerion. McCoy n coleues 9 exine   le olle uen il y repeiively life los fro floo o knuckle i   re reies lifs per for  b ion 4 ec inues ifin bou of ee onceinue iou n of on iTy worpee iffereni yp of oinl bels:  be wi  pup n ir  poseriorly n e li  be prviuly esribe in e MGill orn n S 990 uy. fr xinin e vriou niue of lo  subjec  ce o lif in  ree oniion  reercer no  in els inrese    ubje wre illin o lif y pproxiely 9% Ts vince y n e suppo o e eoY  be iv peope  fle sense of secuiy

Summary of Prescription Guidelines My erli rpor on bck el MGill 993 psene  n vin  neir pleely uppe nor conene  ein of boin bl fr inui orker. Afer oe borory uie n fiel ri y posiin wi s bn ipeene by everl ovrnens n corpoion  no n Givn e vible lierre i woul pper e univrl ecripion of b ie, prviin bels o ll orkes in n inuri operin is no in e be inees of loly ucing o  risk of in n consion o. nin jure wkr o no pper o enjoy ny iionl nefi fr bel erin n, in fc y b xposin elve o e isk of  or evere injury if y w o beo inure Moove, ey y ve o confon  prbe of ening  elv f e bel Hoever if oe iniviul worker prive  benfi fro bel wrin ey soul e llowe o er  b coniionlly u only n ril Te noY coniion for prcripion for wic ere sou e n o xion e s follos  Givn e concen rrin inre oo ressure n er re n iu of libiliy l nies for bel werin oul be creene for crivulr rik by il pronne  Givn e oncen  el erin y provie  fle ne of suriy, bel werer us ceive eucin on lifin enics bck cool Al o ofn, bl e bein prooe o inury s  uick fix o  injuy prol ro ion of els conuce in i wy i einl o  ol of reuin injury s i ric  focus fro  cuse of e inu Euion pror ul inclu inforion on o iues ecoe inure eniue  inii uuloskeel loin n w o o bou feeins f icof t voi isbin inury. 3 Conulns n clinicins sou no prescrib bel unil ey ve onue  fu ono ic sen of e ini viu l' job. Te erono ic ppo u exine n ep o correc e cuse of e uscuosklel ovel n ovie oution o reuce e excsive lo In i y bes oul ony be

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Low Back Disorders

se s  spplement   e ns, hle  gete plnwe emphss shl e n he eepmen f  cmpehense egnmcs pgm. 4 Belts shl nt e cnsee f ng-tem se he jecte f y sml scl be pgm sh e t wen wes m the elts y nsstg  mty pcptn n cmpehense ftness pgms n en  ltng mechncs cmne wth egnmc ssessment. Ftheme s ns  e wse t ntne glnce  mtng fme be wes   pe f tme fllg elt eng, ge ht ths pe pps  b ch cteze y n eee s  ny.

Reference Adam MA and utn W 988 Mehanis  the ntevetebal dis n: Ghs P E( 7 bl h bral ds.Ba Ran L: CRC es CiiellVM and Snk S 995 The efet f ak bets n lumba musle fatge S 20 27-278 Ganata K Ma'as WS and Davs KG 997 Bimehanial asement f lftn dynm musle atviy and spinal lads hile using hee deent sye lfting belts al Bmhas 2 2 07- 5 aman, EA Rsenstei n R.M F kman, P N and NigG A 989 Efets f  et n n  adminal pessue dn eigh lftng d . ad S  Sr ad rs2 12 8690 unte, GRMGuk, ], Mtan eaman P hmas B and AntnR  989 he efets f a eiht tann belt n bld pesse duin exeise jual q( ld S S arh 3   3 -8 Kau  Bn, KA MAtu, DLP eek-Asa,   Samaneg, Land Ka  99 Redtin f ate lw bak nes y use f bak suppts Iraaljual q( Oaal ad Evmal Halh 2 264-273 Lande JE undley JR and Simntn RL 992 The effevness f egh belt dng ml tipe epetitins f te quat exeise d ad S  Srs ad rCs24 5 0309 Lantz SA, and Shultz AB 98 uma spine hsis eaing  Rettin f gss bdy mtn S    8 834- 837 MCyMA Cnetn] hntnW L and ang B  988 The le f lifn belt n mnl ltn aalju al 0dusral Er m s 2 259-2 MGillSM 993 Abdminal bels n indusy: A psitn pape n hei assets lablities nd use ma dusal H ssa jural54 2 752-754 MGll SM and man RW 987 Reassesment f the le f ntabdmnal pesue in spinal mpessin Erms 30     565 -588 MGl S Nman RW and ShaatMT  990 The efet f an abdmina bet n tunk mle ativity and intabdmina pessue duin squt lits Erms, 33 2 4710 MGl SM Seguin Pand Bennet G 994 P assve siffness f the lumba  s n lexn exteninlateal end and axial t he effet f el eain and beh hlding S, 9 6 696-704 Mihell, LV ale H, Ben D Me W , Asundi P , and Pu sel   994 Effevenes nd stefetveness f emplyeissued b ak elts in aeas f h gh isk  bak nuy jal 0/ Ouaal d 36    90-9 4 aems n A L Andessn GB] and Shut A B 986 alava mneuve mens Effets n lma tun lads f elevated ntaadminal pessues  1 5 476-479 atinl ntitute f Opa tinal Safety and eah  OSH) 994, uy Wkpe e f b belts US Depatment f Health and uman Seves Centes f Diseae Cntl n d P even tin Rf W  and MGl S M 996 Admna ets nease dast ld pessue jal 0/ Ouaal ad Evrmal d 38 9 925-927

Te Questo of ack elts

201

dd C  Cogto  h so,  D, ad MotgoY F 992  vatio o  wightitg bt ad a jry prvtio triig ss f airi bagga hadrs Apied Ergonomics, 23 5 39329 y,  Lggt S Ky K., HosBd Mooy  5) h ct o bar bs o isotd ubr s Si 20  ): -73  Pop M..M Kos W v dr o    99 ubar sppos ad dutio o th prvto o ow ba pi i idusY  rdoizd corod tria joural th A mica Mdica Asociatio 29: 789-79 Wsh E d hwrt K 990 h   o rphyat oth oss o bdo  srgth d ow ba ijuy i th wor pa Am ricanora ofPhyica Mdici  ad Rhabiia io 9 (5 25-250 Wss Grdr L.I, Ldsitt D ohstoad ohstoM 2000)  prosptiv dy o a s fo prvto o ba pai d iry Jona  0/ h A mcan Mdica Asciati 28 2 2727-273

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Low8ack Rehabilitation

he developed in previous chapters on ow back fnctionevidence is used o justi etter rehataton approaches.

T

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CHAPTER

Building Better Rehabilitation for Low Programs Back Injuries

e evdece peeed   oo uppot e etalet of pe tably fr fo lowed ( oee y pe ol y  oe ac  ured pae People wo ae o elped y t pe tazato approac are geealy toe codered o e faled ac o patet fo oe loog fo coal eace e ad pa  ele f to atee eeg perfoace eacee  eeft fro te pe talzato approac vdece preeted trougout t oo  uaou a pe doe ot eave le a ee o oulder ad appoace a wor wt tee jo ae ofte ot effecve for ac erapy Loadg ougout te rage of otowc wor wel for o  te extete te ee of ay ac at lea  te eay tage of realtato rg  perod rag for tegt  ore ofte couerproducve. Ufotuatey e prple ued  odyuldg pervade reatao clca wdo  approac yperrope ucle a te expee of deveopg fucoal otoroo patte eeded for optal eal  t capter evea geea ecoedato to axze te cace for ucceful ealtato are dcued folowed y coderato of t tage of patet progreo ad gudele for developg te et exerce rege fo eac pate. po copleto of  caper you wll udetad ow to get ad bac t epod ad ow to develop ette pogra

T

Finding the Best Approach Gve te wde vare y of ow ac pa e oe caot expect to e ucceful  lo ack eatao y reatg eveyoe w te ae coooo progra e follog cocept wl elp gude clcal deco o dvduazead u optzee realato progra 05

206

Lw Back Drde

 Training for health versus performance. e noon a al are ay  gnaly a y a lea  ro a ucul ol al po n of ve r ann f or uperor aec proance dand ubanal ovrload o e ucl and ue of  on An vad r of njury  aocaed w alec ann and foanc Unfounaly, any paen oberv  oune ued by al o nnc p rfor anc and ongly conclud a copyng  l lp r on bac Tranng for al qur qu a dfern ploopy;  epaz uc enduranc, oo conol perfecon and  annanc o ufcen n aby n all xpcd a Wle rng  no a argd goa reng an do rul.  Symbiotic integration of prevention and rehabiitation approaches   apy rgoouly followed wl no poduce ul f  cau of e bac roubl  no addred. ar  provded gudelne fo rducn  r o bac roub l ovng e ouc a xacrba ue oveload canno b overd non and van uldr (1) deonraed e ecacy of xrc for rvnon exec a e obecve for bo b prevnon and rablaon ouco  Establishing a slow, continuous improvement in nction and pain reduction.  ru of funcon and reducon of pan, pacularly for  cronc bad bac  a lo proc e ypca paern o ecovery  an o  oc ar rcng oy. aly and even wly prce flucuaon vnually rul n r prce ( fgu 111) an av good day and bad day. Many e lawyer ave rd rva nvgaor o a clandene vdo of bac roubld ol pron a a appar nonn  a red o povd con o o e eol a ru alngrer and  caug Oe ar ply avng a good day on  day y are vdeoad.  e al or o ovn aooy conn  er conc ory and y a xoneraed • Keeping a journal of daily activities ocunng daly bc an a ff n  enal n denyng e ln  ecancal cnao a xacrba  roubl o crca coponen ould be recordd n a daly oual o  bac el and a  a and acve r perored. Wen an ncoun repead

 0 

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2002 Figure  The positve slope. The establshment of mpovement in back symptoms is often similar to the move ment o high-peorming stocks on the stock maket. While stocks fom a noisy signa with ther shorttem fuctua tions, mimicking the day-to-day varatons n back symptoms the average pogress over the longer duaton has a postve sope. Rehabitaton chalenges should never be nceased unless a "positive slope has been estabished o symptoms and function.

Buldig Better Rehabiltat Prgram fr Lw Back uie

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sebacks, he shou  o ien a common ask o acivi ha pecee h oule. ikese, even when pogess is slow paiens wil e ncouage  s some pogess noneheless. Wihou efeing o he ia paiens someimes  n eaze he ae impoving • Ensuing the "positie slope in pogess. Ove he nex wo chaps I  inoduce he ig hee execises in iffeen foms. We esigne hse exciss  spae he spine of age oas an o goove saiZing moo paens. s h h  salish a posiive slope in paien impovemen. Once he slope s saishd ou ma choose o a ne execises one a a ime The paien ma olae som exeises ell an ohes no so well. f he impovemen slope s os afe adding a new acvi, emove i go ack o he ig hee, an eesash he posiiv sp If he paien euies avance oecves fo ahlec pefomance phaps spin mo ii ou ma a execises o acheve such oecives afe esaishing he psive sope. Ho on shoul each sage e? Thee is no single answe fo all acks oe wl pogess quickl whle ohes will euie gea paience. This is he o of h clinciano eemine he inial chalenge o gauge pogess and enhance he halnge accoingl an o keep he paien moiva evn uing peiods of n appaen pogess The ga clinicians en keen clinical skils an expeience wh sienifcal foun guielines an knowlege. • Is the patient willing to make a change? Obiousl he pain mus change h cuen paens ha cause him o become a ack paien. Ths wil euie moivaion, whch is no awas eas o esaish Ohes have ise he impoance of an seps in eveloping a change in moivaion an aue .g., anne, 197 if such a pogam egins wih he seing of oalsfo exampl uning o  specific o o paaking in a eisue acivi The emploes ole in enhancing moivaion is o ensue h moifie wok is availale ogehe h he oppoun f guad eun  o u Emploes can also pa a oe in mvai on  foseing  culue in whch woke success euaes o compan success whch in un heps h wok Th scon sep in a moivaion pogam is o fomulae a alisc pan fo echng h goal esalshe in he fs  sep   is beon he manae of his ook o evelop he componens of mananing an enhancing moivaional oppounis a eh sage of ecove

Stages of Patien t Progression efo we can uneake  emo ve h acviies ha exace ae ow ack u s e mus eemine wha he ae This is a cucia pa of he ehaiiaion p css Uncoveig he acviies ha caus ack ubles egs wih a pin inevew ome ciicians also pefm povocaive esing a hs me as we Chape 1  hoou gh  iscuss es how o nev ie an  es he paen. O nce his has een one, he ehaiiaon ca poceed The clinician ma choose o ov lap he sages involve n hs pocess o conuc hem i paalle A al s howev  he ocive is o esalsh a m impoveen

aia h e posiive slope o conin u 

Stage 1. Awareness of Spine Position and Muscle Contraction (Grooving Motion/Motor Patterns) oe people ae ve o awae an ae ae o aop a neua spne o  x spne on comman Ohes can e fusaing clueless.

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Distinguishing Hip Flexion From Lumbar Flexion he iniia oecive of his sage is o have he paien conscious sepaae hip oa ion fom uma moion when fexing he oso Fo he moe diffiu cases we pica egin  demonsaing on ouseves uma fexion vesus oaion aou he hips Ohe echnies ha we have found paicua hepfu ae as foows: • ave ou paien pace one hand on he umm whie pacing he ohe o ve he lma suface This wa she can fee whehe he spin is ocked and moion is occuing aou he hips see figue 11) • omeimes paiens ae ecepive o eing coache whie using a pacice oad The dumm consuced  nuses o hep hem ehease pop paien ifing and shown in figue 84 on page 179 is an exampe of such a pacic oad • Ohe paiens espond we o phoos of people coe doing asks ha h wi  also e ca ed on o o in he cous e f hei  os o hi eveda aciviis Figue 113, a and  shows exampes of such phoos

Figure 2 For people wo are no boy aware an ae unabe o aopt a neur a o a exe spne o omman we sgges a) reearsng te spneeutra poson an p (not mbar) flexo we og knee bens befoe (b exeon

Figure 3 Sometmes paes ae eepve to ask-spe llustratos sowg spe an p posres A esue woker s applyng a pulg ore o e vm w e spe exe a) Dssso w e paen of ts fexe spne posue ogeter wt one a woul beter spare te spe s very epu Also ssse are exerse posures su as e eutral umba posture aope by s pae peformg abe puls (b

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

Figur 4 Wokes eate to tasks wt wc tey ae ama. Tese potos of constucton tasks ae elp o constcton wokes especaly snce tey can eadly see te d eence between te ncoect a) and  and coect (b and d spne postues.

• efo (incorc n e corec phoo uch  hoe in gu 14  hrogh  cn  epecilly hepf • Y noh chnqe  o plc  ick long he pine wih he inucion o flex h oro forw ing he hip b mnn conc wh h ck ovr he lengh of h pine ee figure 115 c Whil hi egn n he cinic oh n more compx, benng k cn lo help o gooe hee pn no h gnrl moon p ue in wok n ohe y civie • When  of h mp fil w ror o he fnl echnique: hvng he pien porm he minigh movemen" (olng he pei hi i lub moion (No figu hr! Inrengy ome pien who foun ex pn never oci pvi ing h lmb flxion Poning hi ou o hem oen fcle hir mk ing h nx lp n pine poion we ne n in beng ble o vo hee pnul moion n po

Onc you bgin   h ny or evel of he echnique u i r hepng h ifficl pien lern how o chieve n minin neurl pin poion ng hir y cvie yo my hve hem emp om k o e if he concp of h neurl pine i becomng ngrine One uch k i o k he pne ick n k he pien o knock on n mginy pie wb ovh in h coner of h oom  he loe he lumb nr poure poin i ou o hm o h cn coec i n obviouly conine pne poion wrene rnng Some peop hv  vey icl ime emembering he pociv nerl pine pen W el he ype of pien o 1 op efor n exerion pehp por o ifing  hoehol iem   pc h hn on h mmy n mb egion

20

w ck Disrders

Figure 5 Placing a stick aong te spne wit te instrction to lex orwad bt mantan contact wt te stc over te lengt o te spne wl ep patents sepaate ip rotation rom lmba moton wen lexing te toso Exampes o motons tat can be sed ae sagitta pane symmetc ts a varos treedimensiona cable pl exercses (b, and speciic wok tasks tat are amiar to te patient  3 pacic a fw kn n wit t mn at  ip an nt t lma pn an 4 tn prm t lif  ig 11.2 a) Ti practic i ffctv fr man ppl

Maintaining Mild Abdominal Contraction Mantainng a m cntractin  t amnal wall can al lp nr icin pn aili T manvr  cal amna llwing  n man ack car cir l t w prr  av a trminlg a i ggt t m t ppl itr ping  n r png   amina wall Wn t cnracin i prfm crrctl, n gmtic cang a all ccr in t aminal wal. In r w ratr an llwing n"  amina wall t patin mpl acivat t mc  mak tm if. W call ti cntractin amina acing" wra wn w pak f aminal llwng w a fng t  plng in   abmnal wal S lw

A Note on Abdominal Holowing and Bracing Sm cnin x in  inrptain  t lita rgaing t i f amnal wng an aminal acing. icarn' gp v ta t llwng  igr  6a) f t aminal wall rcrt t tranv amni On t r an an imtric amina rac  igr 11. 6) cactvat t tranv amini wi  xtrnal an inrna iq t n talit n virtall a m f pil inali Qkr  a. 1998) Nt ta n racng t wa  nitr w in nr p t. n ti wa aminal racing i prir  amina wing n nring taili. Wi ti ackgrn carn an cllag 999) n tat t rcrtmnt f tranv amini i impair fllwing nr. T gp vlp a rap prgram ign t cat t mtr m  actvat tranvr amn in a nal wa in

Building Better Rehabiitatin Prgram fr w Bac nurie

2

BD patient Th while holowing ma act a a moto eecation execie, the act of hollowing oe not ene tailit. Some cinical pactitione ma have miintepete Richaon' wok to gget hat aominal holowing hol e ecommene to patient who eqie enhance taiit in oe to pefom ail activitie Thi i migie ominal acing, which activate the the lae of the aominal wall extenal oliqe intenal oliqe tanvee aomini with no awing in i mch moe effective than aominal holow ing at enhancing pine tailit McGil 200; Genie an McGill, in pe) .

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Fgre 6 Hoowng volvs h suckg in o h abdo to actva ransvrs abdois On h ohr hand h abdoina bac actvas h thr lays o th abdona wa a) (xra obliq ntnal obiq ansvs abdoins wh o drawg n (b

Two mechanim can he ome light on thi ie of holowing veu acing. it, the ppoting gu wie" ae moe effective when the have a wie ae ee figue .7, ac), that i when the aomen i not holowe. Secon the olique mut e active to povie tiffne with cicoing tut which meaual enhance tailit. The lma too mt pepae to withtan all manne of poil loa incling teatate loaing whic h ma e a com plex comination of fle xion/ extenion ateal en an axial twiting moment) an en nexpecte com plex oa togethe with loa that eveop fom planne alitic motion. Stiffne i eqie in eve otation an tanlation axi to eliminate the poiilit of ntale ehavio. The aominal ace ene cient tailit ing the olique coacing althogh high level of cocontaction ae ael eq iepoal aout 5% MVC cocontaction of the aominal wal uing ai activitie an up to 10% MVC uing igoo activit.  quantitative compaion of the hollow an the ace i cleal een in an inivial taning pight with loa in the han. Simpl hollowing can caue the tailit inex to op to low level o even negative level which inicate the poiiit of intailit ee fige .8. Bacing inceae the poitive tailit inex vale. The ject in thee fgue i tpica in that even thogh the hollow wa taght to taget the tanvee aomini al aomina mcle wee activate when ma ue. Th tailit wa ceate while attempting hollowi ng" althogh tue aing i peio to ceate lma tailit. If a tue hollow" i accompihe with jut the

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Figure 7 Hollowg e msces reduces te sze o e base o e gy wres togeer w te ncdece age were tey atac o te spine a) Ts erey redces er cobon to spne sness  varos modes wc compromises spe stabilty (b Bracig assists i keepig a wde base o te guy wies ad recrus e obque muscle o sppy cossbacig sruts for stabily n a axes c

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Figure 8 A example compang te olow a w e brace (ge sabiy i an divdua sandig prigt ams a te sdes w loads placed  e ands A "peect" ollow was sow o be nerio o te bace  n is aalyss o simuaed mscle activaon

Buildig Bette Rehablitati Pgam f Lw Back uie

213

ransverse abominis as smlae in figre .8b sabil is o compare wih a brace here he hree aers of he abomnal all are acivae imp  holoing cases he sabili inex o rop o negaive eves when he oa s pace n he hans compressing he spine. A negaive vale incaes insabi s possle. In conras bracing manains a posive sabili nex vae eliminaing he possbi for bing.

Teaching Abdominal Bracing

Fgure 11.9 EMG biobk vs r  oom wy o povi fbk o th pn grg h v o boi von ring ny typ o  o sk, fo sng on  wobb bo o gting ino  .

Generall o emonsrae abominal bracing  he paen we siffen one of or on oins sch as an elbo, b simaneosl acvaing he lxors an exensors. The paien hen papaes he on boh beore an afer we sifen  hen e as he paien o aemp o siffen her on on hrogh si mlaneos acivaion of flexors an exensors Once she can sccessll sien varios periphera oins e emnsrae (agan on orselves ih paien papaion he same echnie in he or so achevng abomn a bracing. Fina  e again as her o repcae he echnie n her own oso Occasional we se a porable EMG monior so he paen can earn hrgh bofeeac wha or exampe 5%, 0%, or 80% of maxmm conracion feels lie see figre 19. We se simar evices o each paiens ho o mainan he conracion hie on a wobble boar an in fnciona saons sch as hen pic ing p a chil geing on an of he oile an geing in an o of cars.

Mntal Imagy he se o mena mage is sel for boh spne posiion an msce acivaion awareness. Fooing is a genera prooco ha we have aape from he imager lirare for se h spne raining.

Steps of Mental Imager 1 Focs on eeing he srace ner he fee or bocs Whaever b par s ochng a srface e aare of he sensaion. 2 Pracce simple moions sch as ighening an hen reaxing specific msces in feren areas of he bo. hen graae o performng he abmina brace 3 Palpae, an have he paien selfpapae, he msce involve hie h s aemping o ghen an relax  omeimes a flbo mirror s help. he ocs or he paien is on he speciic mscle(s involve 4 Perform moions sowl chning hem ino segmens an seences hen visa ze he oa moon. or exampe begnning wih a simpe as sc as a forar reach, vsalize e neral spine hen acivaing he exensors an e bracing abominas, an fnall he moion ao e hps. 5 Pracce he imager inepenen of phsca acion. O corse he paen w have alrea been sccessfl in learning spine posion aareness proper msce conol an esirable moion paerns. Source: Kathyn cill, spos psychology coslta

214

Low Back Disorders

Lumbar Spine Propriocepive Training Givn  h n h mpn f pn pin wn  p h pn n  xpn n hing pining w bm in in pp piv ining f h bk Th  h vy i vin w vilbl  vli h  f pppiv hbilin f h mb pn miv  n wk n pn ppipn P n MGl in p. Th p p  h wk w  niy h f   xwk hblin pgm gn  impv lmb pin piin n n iing bn Twv b wh  pvi hiy  LBP w vny pl n  ining gop n  nl gp Sb n h nl gp iv n nvnin hil h b in h nng gp v  20min hbilin in h m p wk mphing pin biin x wih  nl pn. mb pn pining  n pin knling n iing bln f h nng gp h ignifin mpvmn v h y. Thi mll b iniil y mn h ppipin n pin wn in h lmb pin n mpv hgh iv hbliin

Stage 2 Stablzaton Exercses to Groove Stablzng Motor Patterns and Buld Muscle Endurance Gnlly h nx g hl bgin wh bin xi Th ik i  in n ppp ing lvl F h hni bk " wh iv   nv y li ni hvng fl inl hpy w gnlly n h wh mny wl ni n pppi ling lvl Th ypil pgiv impvmn phl phy f wk hning" wh wkly mpovmn gl will n wk  h pp Thy wi l hv g n b y b h gn l piiv lp n  mpv mn m b bihhwv g Th ifl  will n l h wky impvmn  gl  iinl wk h ning pg m; hy  m  pin On w n mn  piiv lp in mpvmn hn w n in h hbiln hlng. Spif xi  l in hp 1

Stage 3. Ensurng Stablzng Moton Patterns and Muscle Actvaton Patterns Durng All Actvtes Th nin m iy h ng f vi ly livng pin hl  f whih h invil pin m b pp Thi  bin hgh inviw Whil h i n n fm  bgin by mning h pn' y n whh inl hi pinl mn n h f ly lvng. Pvi hp f mny xmpl in whih h pin i p wih n pp pi p n m vn pn Th gln  lng x  in h nx in wil hlp y mn wh xi  pib f pin n  ihning g  In i in w pn immin h n ing m ly vii b   h pin n iliZing pinping ml  ivn pn.

An Imporan Reminder mmb n hlf h bl   mv h iin mk   fllw h mmn n  h pvi hp.

Building Better Rehabiitation Programs for ow Back Injuries

25

Summary: Stages of Patient Progression 1 Int n  t xctng ctt 2 c n  nl  w t ck f  wl  t tk n tt pf 3 Dlp pn ptn wn p   mtn n t lt t ntn nl cng. G tn/t pttn. 4 Bgn t pppt pn xc n pppt tlztn/lztn tk 5. mcl nnc 6 Dlp Tnf t l ctt. Nt tt tnng tlt n  pgm nl t m tg wt t tn f tw tgtnng tngt n pw  cpt 14

A Note on So T issue Treatments Ptnt ftn pnt wt lcl  p n fng" cl c tt  pc   g mn cn cncn. Ft t p n lcl ncptmnt    ct wt g f nct n f t gnt n ngt c nl n  nt In n c t nctn l cr  pnt cplt cr Cncn   t f ft t ttnt t  p  n  t t tt cn p ttnng  n  cl n nt nctn Dcntng t  n t cp f t k T   pl  t t ptntl gncnc n  n lttn

Guideines for Developing the Bes  Exercise Regimen T pt ffctn f  tnng n ttn pg f t w ck  qt l wt  clmng gt cc wl t pt n c c  n ngt lt F 99 6;  t  99) T cpnc gng t ffctn n ft f xc pg  pl  t cncn p cng npppt xc c t  nt ntn t t lng tt lt ng  tk. t t g t nnc  t t d wt t l tng t. Tt t  f gt cnnnc n t ug r cc  w wl   l t c ptnt pn n t t lt t cmplt tk.

Developing a Sound Basis for Exercise Prescription   lct n t t xc n t flwng cpt d n t lng nc n t knwlg f w nj cc t pcfc t ( c n p cpt. Cng xc w tll nl t t ct g tt  lp tg clnc xpnc T fwng xpl lltt t n f nttt n n  t t t ft f tn xc. W   n tl t pf tp n t flxn xc t t kn flxt n wt nc Sl pt  ggt tt t  t p n/ cng t ln f ctn f t p MI t Sntg n McG 995) ntt tt t p ln f ctn d nt

216

Low Back Disoders

hnge du e o um br or hip posure exep  /S s he pso s mn e h o eh verebr n fo  ow he hng ng orienion of he spne . Hoever  here is no dub h he psos is shorened h he fexed hp, modung fore produion u he ueson remins s here  reduion in spine od ih he egs ben? n 1995 MGi exmned 12 oung men using he boror ehniue desribed pre vous nd observed no mor iff erene n  umb r od s he resu of bendng he knees verge momen of 65 Nm in boh srgh nd ben knees ompresson of 60 N h srgh 320 N h srgh egs nd 340 N wih ben knees sher of 2 egs nd 300 N ih ben knees Compressve os in exess of 3000 N erin rse uesions of sfe This pe of uniive nss is neessr o demnsre h wheher o perform sups usng ben knees or srigh egs is prbb no s mporn s heher o presrbe sups  ! There re beer ws o henge he omins

Basic Issues in Low Back xecise Pesciption ever exerses re reuired o rn  he muses of he umbr orso bu whh xerses re bes for  gven nividu? Mking hs eermnion i depend on  number of vribes suh s he indivdus fness eve rnng gos, hs f prevous spin nur, n oher fors However depenng on he purpose f he exerse progrm, sever prnipes pp For exmpe, n ndividu beginning  posinur progrm woud be dvised o void odng he spine hrughou he rnge of moin whie  rned hee m need hieve higher perfrmne eves b doing so. noher gener e of humb is o preserve he norm ow bk e simir o h of uprgh sndng or some vriion of his posure h inimizes pin Whe in he ps mn nins hve reommended performing  pevi  when exerising, his s no usfied we now know h he pev  inreses spne ssue oding s he spne is no onger n iesi euibriu. Thus he pevi  ppers o be onrndied when hengng he spine. Bsi ssues ou shou onsier hen presribing exerses for o bk rehb re ds ussed n he foowing seons

Flexibility Wheher o rin for opimizion of spne fexibi depends on he persn's inur hsor nd exerse go. Gener for he inured bk spine exbii shud no be emphzed un he spne hs sbiized n hs unergone enurne nd srengh onionngn some m never reh his sge! Despie he noin hed b se here s e unve d o suppor he de h  mor emphss on runk fexbi w improve k heh n essen he risk of inur n f some exerise progrms h hve inuded oding of he orso hroughou he rnge of moion (in fexion/exension er ben or x wis hve hd negive resus (e.g Nhemson, 199), nd greer spne mobii hs been ssoied ih  bk rube in some ses (eg, ierngorensen 984) Furher reserh hs shon h spne fexbi hs e prediive vue for fuure o bk roube (e.g. uvn hof, nd Ride 2000) The mos suessu progrms pper o emphsie runk sbizon hrough exerse h  neur spine eg Hdes Ju nd Rihrdson 2001; S nd S 989) he sressng mobii  he hips nd knees (rdger, Orkin n Henneberg 1992 emonsre vnges for sng nd snding hie MGi nd Normn 99 ouine dvnges for ifing. Fn, removing umbr fexion from morning ivies subsni mproves piens on verge (nook e  , 99 ) Despie hs evdene, mn pen s re si nsru e o p u her kne es" o her hes n he morning nd perform oe ouhes see igure 110 . The desbZing onseuenes of  exion were desribed n hpers 4 nd 

Blding Bee Rehabliaion Pogams fo Low Back nuies

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Figure 11. 0 "Siy sreches, such as a) and (b puling the knees o he ches and c toe ouches, are ofen prescrbed to paens o do in he moning. Thes e can cause insabiiy!

or hes reaons toro flexiity exrcses hold e mitd to oa io ad xteno for those concernd wh afty hose intrsted in pcfic ahi ativites may somtme  an excepto to this rl (Of cor sin flxly may  more diral  athlete who have nevr sffrd ack inj.

Strngth  nra strngth seems to have little to do with ack health even thoh incras orso mscle strenh  a opar ojective of ow ack rehailtaton roos. ak msc strth  particar ha ot  fod to  a sifcat rir of rst tm jry.  th contex of cae and effec predtng frsttim injry offrs s ia nsight.  Oy Trop, Martn, and Loyd 91 f ond while tsig torso mss hat rdcd dyam stregth a a prdictor of recrg ack an. ovr  a rostve sdy Lno ( 19) fond that neithr iomtri c or dyna m rk sr predted th devopment of o ack trols over a 10yar folo ro. Th rSornse 9 stdy previoly oed fo tha iomric ack rth did ot prdct the aearanc of low ack trole  prvoy hahy sjecs ovr a onyar folo. olmstrom ad Mortz (1992 rcorded redcd omri rk xtsor edranc mes n ma worker with lo ack disorder compard o hos thot  fond o differnces in omtric xo or extnio srnhs trnh apar to have ittl or a v ak rlaonshp with ow ack hath. rth is or ahet performac ojectives.  conrat mc ndrac whn arat m strh apar to e kd wh ettr ack heath.

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ow Back sordrs

Most cnt  v sggst tt  ving  stoy o o ck tos is no t o c stg, it s t o  pt xiooxtnsio stnt o McGi t , in pss). s ic i t io pp o  iny in nc y t xtnso stngt tiv o xo stnt in tos it os.

Endurance o cosssction stis tos o Nicoisn n Josn (98  A   (1994), on c xtnso nnc in oks o po o ck os Bo Biingos 984)  Loto n cogs (995 sgst   soic stng s o ssoci it t ons o ck tos poo stic ck nc scos . o v xpss conc t ptnts i poo sc nc scos v poo scos o  ck o ot  psycooic vi) t  ny pysioogic iittio.  c sty y Mio n cogs (00) sggst tt o  to vc s in t c scos o t ck ptints, 40% s xpin y pYioogic tig (tii s cis i t MG po spct, i ony 10% s xpin y psyco oc vis nti s oivton n  o p vis o  qsto  A cn sty cG t . in pss s sggst t vin  soy o o ck tos pps to  ssoc it   xontoxsio  nc tio it  xtnsos v ss nc n  xos vg o nc. is inc n nc so pp   igt   si  sct s vinc y t syt i it   nnc oin tis  RB/L tio o 93 o tos it  LB stoy vs. 0 o tos itot  nxt iss ss t qstio o t snt n nnc   ntsy, t xo sngt  to c (sc to s  tn 3 n 35 o t xos  o no" cks  in tos it  istoy o tos,  o t xtsos o  os  io s. c  o  

xtsos (3, p 033 in tos   istoytt o LB  sy, sv sts v sgst iiis tk xtso  c n o stnt is ink to o ck os. Rcnt t coi tis notio n nnc it t y sstig t t nc o nnc t xo  xtso scs  t nc  it n t sis o t toso pp to  k o  sY o ck tos sv no to st in ok oss. No tt ts  osss t in o t t ising piso. n tos t  istoy o is i L t v t o i sic t st ok oss pso s 1 ks (s viion 5), i t v gt o ti ost o ok i t piso s svn ys st viio 0  sson o xcis pscipto is t gt, possiv xcis pos (i., o ong tio  o o, ic psi nnc, ts s p ov sti xciss. =

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Aerobic Exercse Motng vic sppoin  o o oic xcs in o i  i nc o o ck injy Cy t  979 n t o ck pts Qk t , 1998 is copi. Rc invstiion into os sst y t o ck tisss  kin Ntt, 988) cois vy o vs o sppoti pssv tiss o cop  i, t poog ctivio o t sppotin sc t. Cgn Pt  McG 999 oc tt s king t t s sigi sts i o osciig spin os. W o, oic xcis picy st kig, pps to c  cts o ckspciic xcs

Buildng Better Rehabiitation Programs for ow Bac nures

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Order ofEercises Within a Session ecuse the spine hs  ling ey  p ctiity cn ulte the biechnics f the spine in  suseuent ctiity F exple f  esn st in  suche stue   ei  tie sufficent t cuse ligentus n sc ceep she u he esiu  l i ent lxty f  pei f te We he esue xity  e  h hu in se cses McGl n wn 992] The nuceus lue pes t eistibute upn ting  stning pste Kg et  19 Ths eistbutn tkes tie f the spne is exe n ne neue then it pby shu tun t neut  extensin f the next Viscsty is nthe ey f igicl tssuesn this cse  ctin esistnce t tn ithin thep sine ts tissues why tn usuy ee ist s  n  wu nceThis the isiscus fictnexecises hs beeneeuce suseunt tin cn be ccishe wth less ste ss A fn cnsietin is the nee t cntnuly ge hety jintcnseng n stbizin t ttens Deening n the execise ecties e ften begin n execise/tining sessn with se spnestiiztin execises t ge th t tens tht l cntinue e t the execises n the pg n su une stnin sine iechnics cn tize the eng f tss in  tnng sessn

Establishing Gooved Pattens We he fun tht tients e best see hen we estish the ge t tes  spine stity t the eginnng f the sessn On the he hn in  pef ceente tinng pg ptcints then e n t tsstbiiztn execises t the en f te sessin

Breathing ete cntinues eging the entinent f ething uing extn hu ne exle  inhle uing  tcul hse  eent  exetin n the e cses f e hey lifting  xi  exens whi ch ul nt be  t f  ehbittin pg high ees f intinl essue e uc by bet hing usng the Vlsl neue This elete AP hen cine it hh ees f in ll ccnctin in ensues sine stffness n st biity uing these extiny ens the ttn gien f  sting t chiee highe AP s the nee t u ce the tnsu gient in the cniu t lessen the is  lcut  stke Mcil htt n eguin 1995 he exntin f ths sk euctin s s ls: •

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uiing AP s sscite wit  ise in the centl neus syste  u essue in the sine hch s n pen essel t the  n in Un exetin enus eletin in  essue ccus cuente in ihtiftes t e el e 400 g) This essue in the cnil esses cetes  ge tnsu essue ient tht is euce f the S fu essue is likeise elete eucng the  n the scul essels

Athugh this expntin is i the echnis shul be cnsiee ny f exte eihtlitng chlengesnt  ehbiittin execise

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Lw Back Dsrders

When desgnng rehltton eerse,  jor ojetve s to estlsh spnesti lzton pttens n pornt fetre of sle nd fntionl ks s the lity t oontrt he doinl ll donl e) ndependently of ny n venil ton pttens Good spne stlizers intn the itl syetl se sness drng ny onton of toe dends nd rethng pttes s s when pying  sketl e o eple) Poor slizers llo don ontrtion levls to ye wth ethn  rtl oens hee sty s needed Goovn slr tvton ptterns so ht  prtilr diretion in ln ir lo s entrined t  prtlr pt of n eetion is not hep his wod e of lttle ryver ve to other tivtes in ft t old e onterprodtve

Breathe Freely rn to rethe feely while ntnng he szin isoeti dnl  ntrons

T ime of Day for Exercse s ponted ot n pr II, the nerveterl dss re hihly hydrted pon rsn fr ed the nnls is sjeted o h hghe stresses dring endn nder these ondtons, nd the end pltes l t oer opressve lds s ell hs peror in spneendng nevers t this te of dy s nwse et ny n ediine physns ontne to sgest to ptents to perfor ther therpet tines fist thin n he onn hs ppers to e de to onvenene nd norne es the dss enerly lose 0% f the fld tht they will ose over the orse o  dy ithn the frst hor fte rsn ro ed, we sgest spy vodng this peod fr erse tht s, endng eeise) ether o ehttion or perfne trnn Whesthee hsn't een  stdy on the enhneents tnd eerse tnes  fnton f e f dy Snok nd olees drng did prove thtr the nsos vodne of forrd spne feon in the ong iprove the ptients k troles

No Earl y-Morig Bedig ont pefr endng eerses in the first hor or o fter rsn

Notes for Rehabilitatio Exercise rescription Eerse professons fe he hllenge of desgnin eerse prgrs tt on sder  wde vriety of ojetves Cnsder these gdenes   Whl e soe epet s eleve tht eerse sessions shold e pefed t lest thee tes per eek lo k eerses pper to e os il when pefred dly eg, Mye et , 85   he n pnn gn o does not pply when eersin the l k ptlrly when ppled to iht trnng Senti nd linl isd wold sgest the opposie s re 3 Reserh hs shown tht generl eerise progs th one rdovs r ponnts sh s wking) re ore efetve n oth rehlttion nd inry pr even tion  g , Ntte r,  88

Building Bee Rehabliaion Programs fo Low Bak nures

221

.  vo    lvl o h rvrl   r o

hr rl   org r g ro  g h r o   hrogo   Popl hol o po llrg p o o r lo ho r rg ro  g   ol 995 5. Low k x pro or hlh   o phz rg h glo lowrpo k Rr or rpo o  g xr wl  r  rgh hr  o o h k j   or g gl low lvl    pk g p  pl  h  j  o oor orol rror  or Whl  h o oor orol rror  rl  ppopr  or ppr o r w g v lo   pv  o g hg h gg g g Pov  Nor 199 Gv  r  or prov v  rg Loo   995 rg g ho o  ovrpz  h xp o r 6. o  o x   or ll vl  ppropr xr g ol or  v g ojv  h ro r  g h rk o j  opzg gr l h lh   or xz g hl pror Wl  o vl h opl xr or  o h oo o   ll xpr xp l r   low k l 7 Boh p  l hol  p  k wh h prog I o  ro  p  o or o hr oh g Mh  l 9

References Ams MA  an Dln P  199) Rnt a vns n umbr spin mhnis an  th r inia l signifin inical Biomechanics 10: 3-19 Alrnta, , urri,  , Hlivr, M, Sukk  A nl rju R  ( 199) Nn dyn  tri trun  prfrmn tsts Rlibilit n nrmtiv t Scadnauanjoal /Rehbliti Mdi cne, 26 21121 ringr nsn, F  19) hysi msurmnts s r sk in itrs f r lw b rubl vr  n yr pri. Spe 9 106109 rigr,  ., Orkn,  n nn r, M ( 1 992) A quntittv inv stigti n f lumb ar nd plvi pstus in stning n sitting Intrrltinships with by psitn an hip usl lngh nteaioaljornal 0/ndstl Ergoom cs 9 23-2 Cdy .   ishf f  P , O'Cnnl ER ., t l  1979) Str nth n fitn ss n subs qunt bak injuis n firfightrs Jornal 0/ Occptonal Medici  21  269-272 Cllghn J . Pal A E. Mill SM.  1999) Lw b k thr- imns inl int f rs, ki nmat is nd kintis uring wlking Cln cal Bomechnics 1: 203-216 Fs, A  1996 Exriss Whh ns r  wh ing fr whi h ptints  nd hn? Si 12 2 27-279. rnir, S., an Mil M. (n prss ring, nt hllwing, h minls nns spn stbiliy s, JA , Jull, A . n Rihrs n CA (200 1 ) Lng-trm ffts f sp ifi stbiliz ing xri ss fr firstpis lw b pin Spe 26 E232 lmstm, E, n Mrtz U (1992 Trunk musl strngth n bk musl nurn in nstru in wrkrs ith n withu bk isrrs. Scadinvian jornal 0/ebiito Medie 2 3-10. Jukr  , Mill S. M , Krpf  P n  Stffn . ( 1 99 Quntittiv ntrmuslr m yltri tiv  ity f lumbr prins f pss n th minl wl urin  wi varit f asks Mdicine nd Scence n orts ad eise, 30 (2 301-310

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Lw Back Dsrders

Koes, BW., outer, LM, eckerman H, et al 99) Phyotherapy exercises and ack pan: A linded review British MdicaJra 302: 2176. Krag, M.H Seroui, ., Wilder, DG, an Pope MH 9) Inteal dispacement distriution from in vitro loading of human thoracic an lu mar spinal motion egmt : xperimental reslts and theoretical predictions. Spie 2 0 00. Leino, P. Aro, S and aan, )  987) rnk mscle functon and low ack disorde Ja / ri Da 40: 29-296 Linton,    , and van Tuler, MW  200  Preventative intention s for neck and ack pan pr lem Spi 2 ) 77-77. Loto, S, Heliovaara, M, Hrr, H., et al 995) Static ack enrance and the risk of low ack pain. iia Bichaic 0 323324 Mannche . eeoe G Be n zen, L  . 988 C i n c  of innsiv mu tang for chronic ow back pan Lact 24 473-1476. Mannion, AF., Taimela,  Muntener M, and vorak,  (200 Poo bak ms endurance: A py cho  og ca or phy io ogi ca  ? I: Atacts-I Soce r dy of he L ar pine, dnbrgh, Scoand une 9-23 p. 47. Mayer G. Gatche,  . , Kihino  , et al ( 1 985) Oje ctive a sessment of spine f nction fo lowng ndstrial inU A pspective tudy wth comparison grop and one-year follow up Spi 10: 482493 McGill, .M. (200) Low ack tability: From forma description to isses for performance and reha iltation ri ad Spr Sie Review 29) 26-3 McGill ,  .M . ( 199 The mechanic of toro exion: itup an tandng dynamc fle xon mano evres iia Bimeha i 0 (4): 8492. McGill, S.M . and Bown, S  992 Creep rep onse of the lmar spine to pro longed fl flexion iia Bichaics 7 43-46. McGil, .M., Grener S, Preu ., and rown . (in pre) Asymmetries in torso endurance and strength parameters are aociated with a hit of ow ack troles McGi , S M  an d orman, W ( 992) Low ac iome chanics in indstry The prevention o inju In: Grainer, M. .), rrt ie q/ biech ais  Champaign, [1: uan Kinetic McGil , S M , Sharra tt, M , an Seguin, ] P  995) Loa ds on spna l tisues dring simltane o lif ting and ventilaty challenge rgi 3: 772792 achemson, A (992) Newet knowedge of low back pain A critical look iia rhpai 279 8-20 Nicolaisen , a nd Jorgenen, K   95) unk trngth, ack muscle enduanc and low a ck troule Sadiavi a J a /Rhabiitati  7: 2127 utter , P. ( 198) Aeroi c exerc e n the treatment and preventi on of lo w ack pain patia Mdici, 3: 374 Potvin   , an Norman .W .  992) Can f atge compro mie l ifting afety Prc. NACOB II . Th eond Noth Amercan Congres on Bomechanics, Augt 24-28, pp 3-54 Preuss, . and McGll, S in press) Improved mbar spine pition sene and sitting balance followng a ixweek rehailitation program in individal with a histoy of low back pan anney, D 997) Chonc m uclo seleta l injure i n the workplace Phiadelphia WB anders. aal .A . a n Saal, . . (  99) ono perative tre atment of herniated lmbar intevte a dsc with radiculopathy: An otcome tuy Spie 14 431-437 antag uida, L , and McGil l S.M    995) he p oas maj or mcle: A three-d imeniona l mechanical modelling tudy with repect to the pine aed on MI meaurement Jra /Bieha i 28 3)  339-34 Snoo, S H.  Wester, B. , McGarry, W , Foglema n, M and McCann, K   998 he e dcton of chonic nonspecfc low back pain through the control of early morning lma exion: A randomize contrlled trial Spi, 23 (23 260260 Sllivan, M.S., Shaof LD, an idde, L 2000) The relationhip of lumar exion to disaiity in patient with ow back pain Phyia Tepy80: 24-20. roup . G , Martin, W, and Lloyd, D C F  981 ) Bac pan in indst A pr ospective ey i 6 61-69 Vidman, T, Sarna, , Crite-Batte, M, et al (995) he long term effects of physica loading and exercie i fetyle on ack-rea ted symptom diaility and pinal pathoog y among men, Spi 20 (b) 669-709

Evaluating the Patient

O

 he eval e n  ba vaable dnfi n eaie hape many ae the  eu  njuy They nlude aban lumba mtn pate, pebd m pat  mue umn, and aban jn min wh n man pan an   mul nuan Unftunaly n f hee def i n eay. The hallene   fnd he t hat an be inti he f and that a a an d n ue xpnv  palze euipmnt. The e haanably me anably le  mn he tea a bd in hi hape. Vualy any manual mdn exb be h ypa e  detmnn h ange f mn (ROM). u  hat al impan  h inman t he linian? The nmbe a me f h lal tminan  iablity a deined by h M han f adin n h linia n p m neuy hn ha al paient hul have nma  ava ROM vaue even huh hey pb ably ee n avae pi  bmn a paint. Th t dud n h hape f me eu na  pahy  ai yu n man atmn deiin. Th hap pve guln  t ne t uantfy patnt eit; he eult il m he habliatn bjiv  he pan, geh ih lue  enng ex. It al iu h pan an hlp  dene he wn eha blian tae

First Cnician-Patent Meetng Th m n h ln ht ll hp detemn the type f ehablitain xie. u hul nde thm nly n y hav nd yu paen  all ed la nitn.

 Identi the rehabilitation objectives (specic health or performance obectives). Th pif habilan bv eemn h aptabe i bene ai.  pman bjtve a hh  n h pnple  bdy buln an ahi tanin a  pvaiv, yu ne  b ue ha al paen unan h fn bn ahle pfman bjive and he  pain duin an mpvd aiy unn 223

22

Low Back Di sordes

 Consider patient age and general ondition Younger paiens end  hav moe discogenic oubl (fro the teens to th ffh decade whl ahric spnes tnd  begn dvlopn aftr45 years and noc condions af tha No how aens wak and s  hy n notcay poo conon eher emacad wh ltl musc mass r hea and oos h  ath than musc?  s aso asumed ha paens have bn scend an caed for caiovacuar concns.



Identi oupation and lifestyle details Gnay you hud egn by doc mning patns' day roun: hn and ho hy i from and t to d, ea ouns and xrc an catona hait. Thn ic specifc fcus toad aras of concn F xame f h patent ort achng  f wo hus n th vnng ask for a on h ype of char rang of osus used and  n fr gahring nfomation abou he aiens daiy ouin inqur au ccupaiona dmands. l of hs nfoaon hen addd o h cnca psenan il hp yu vaua cmmn lnk. Dcognc oubl a lnkd wh pongd sng (atcuay prlnd rivng) and peaed oo xon.  passv/nacve lfey is as ascated wih ic oubles. rhtc condns fac rues and h  ae more nked ith job and acves ha nvolv lar ang f min and hher loadng. me ahl uch as soccer playr ao faln hs cag ahough lng-disance unnr o not snc hy do no psualy ae h spn o h end ange of moon.



Consider the mehanism of injury  o -ceae nu mechan a fufu nly hn h a mchanss ar unood Thse we dald n chaters 4 and 5. Once nfd the echanm can b nked wh specfc isu damage much f hch i ohwse no danoabl). Not ny wl h as n desning he hraputc xrcis bu  i aso hp n achng pans to avod loadng scenao ha coud xacrae h dama and sypms  ha  of hes l hav acu on hl ohrs progr loly Sw ons may resu n ome paents ing unab o dntiy the chanism of nju. Nvhss a "cu minang even s uualy nvov. Ca quioning au evens adng up o ha vn w povd cu a o he mchanim of njuy.



Have the patient desribe the pereived exaerbators of pain and sy ptos Pop th pan to cb h asks potu an movemns ha xaceae he an. Examine hes reo ask f a omchancal perspectve o dermin hich sus ar loadd o ratd. Th tsues should  spaed n h xcse herapy and he xacrang mvns mnmzd



Have the patient desribe the tpe of pain, its loation, whether it is radi ating, and spei dermatomes and myotomes Dscion f he yp f pan s somemes hepful; pans ay dscr hr an a dp and orn scachy sizzing a a pon enal ov h ack rgon connualy changn and s on. Yu may nd  he om ol dsci hr ain y offng adjecv to chooe fom In chapes 4 an 5 I cibd h nk bn pain types and specfc tssus and syndrme. Kee n mn hat changng ymom over th shr me f an exanan genraly ugess mo fomyac ynomes whch can omes  rsve o xc hais.



Take dermatomes and myotomes into aount Wh radaing sympms th drmao an myoom can ass n undtandn th nvvd sgmnal evl and whh h an ognats fom a cfic nve o F exae drec sue n h oo cou incae a uniara c buge r end-plae fracur tha would cau a os n c hgh tgeh wh a lo of r oue framen sze n ths ay h spna v can b inked wh h maome r myme bu no he acual sue damag Fuhr nrv o preur can occu a a spcfc spinal level

Evlutng the Ptent

22

n e ue nere nssn t a ae o yotoe  on te asng nre r ao  tee s essue on t aua una entay. us eaes and ys ae an onseatn en n an pnn   nss ny aned o seea tsts tat an nlue eal agng ae tess and s o

 Perform provocaive ess On you suspe at s ssus ae aaged you an ad  t see  loang pus an. Ts s a tesng Many ants a o plx sntaons  seal tssues n. Nneess e prae edu s nas  psues tns and lads ause an and us sud e aed en snng  tau xese. Geneay   s paens sons   ats y n xaan  e an (e st  gu you eson as to  s ssus to a an  stess.  ex ape ua xtnsn t a s an ooe e as wl  ane sea s ay e waaned o sused nsablty (sn n  nex e pages

Specific Tests ea spe tss at an ep yu assss yu atents an an  s appr pate exese a dese n s seon You ae  na juge as to w tess ae eean o s atns.

Testing Muscle Endurance We Bengonsn 1984 sowed tat ease toso xenso nduane pe s tse wo ae at gat s o tu ba ubls nt o as suggested ta teee aan  enuan ang os xtenss and atea usu aue snats se o  a alexos a toubes  ose w ae nt. Beause ese e use gups a noe n sne saty dung uay any tas e nuane sul  easu n a t. Spe ests ta sat tese goups  uss ae u to nd I ose te oon ests ause ea was sown t a  eaby oeents at last 98 o  en peated e e onseue ays (MGl Cs an Leensn 999

ateral Musculature Test Te e mse s ese w e peson yn n e f see poson es e ex ene, n e op foo s pe n fon of e owe foo f o sppo  S jes sppo emseves on one eow n on e fee we fn e ps o e foo o ee  s ne ove e oy nnvove m en s e Te oss e es w e  n pe on e oppose soe F e os wen e peson oses e s pose n e p ens o e on

22

Low Bck Di soders ·

Tesn enne of e fexos (es) ens w e peson n  sp pose w e  esn ns  j ne  60 from e foo () o nees n ps re fexe 90 e ms e foe oss e es w e ns pe on e oppose soe, n oes e see ne r oe sps To en, e j s pe 0 m (4 n) n e person os e some pos e s on  s posse () Fe s eemne o o wen ny p of e peson's  oes e j 

Te  exensos e ese n e "enSoensen poson" w e pper oy nevee o ove e en of  es en n w e pevs nees, n ps se e Te pper ms e e oss  e es w  e ns es n on e oppose soes F e os wen e ppe oy ops f om e ozon poson

Evtig he Ptie

22

Normative Data Nomiv bou du m oll om youg hlhy vduls  ls i b 121 N th wom hv t u th m in h xss. uh h flxo du m (  opoi f h x  du m  hlhy youg m  bou .8, hl oh tt hv yldd o o o hlhy old m. MGll d gu (i p shwd ht h lioh o du mo h o ll d pso musultu  ups  bk tub b (s bl 122) ht us  th ltship ms   h ymoms hv ovd Typlly th xto ndu  dmishd lv  both th lxo d h ll musulu i ths wih li ubl.

Interpreting ndurance Scores p bolu du i obby dy  ntpig h ltnshp mo h h mus gou (flxo ll d x. Nmly h flw  dsi ug ubld d (o h th lst o s  tth to-du o.



Table Test Score

ghsd big/lfd bdg du

> 005

Flx/xt du

> 0

d bdg th id)/xto u

>

xts gt (m/xs u (s

> 40

0.75

Mean Endurance imes sec) and Ratios Normalized to the Extensor Endurance

Me e 21 ys (me:  = 92; wome  = 137

Me

All

Women

Mea

SO

ato

Mea

SO

Ratio

Mean

SO

atio

xeso

6

61

.0

85

60

.0

173

62

.0

exo

36

66

0.84

34

8

0.72

34

76

0.77

RS

95

32

0.59

75

32

0.40

83

33

0.48

S

99

37

0.61

78

32

0.42

86

36

0.50

ak

Fexo/exeso o

084

072

0.77

RS/S o

0.96

0.96

096

RS/exeso

0.58

040

0.48

S/exeso

061

0.42

0.50

RS

= rih s bri; SB =  s br

228

ow Bc Disodes



Table Mean Enduranc e Times Comparing Normal Worers Wih Those Who Have Had Bac Disorders Men men e 4 y (neve   oes n  24 os wo e o O n  26 fom e sme wope Ves  e snfny feen eween ose w  soy  ose wo ve neve  oes ve n ses Noe   men wee sympom  e me of esn; ese e onnen efs sseqen o  oes

isy f disabli ack es

N ack bes ask

Mea

SO

Raio

Mea

SO

Raio

10



0

90

49

0

Fexon*

66

2

064

84

45

09

RS

54

21

02

8

2

0.64

S

4

22

02

6

27

072

Fexon/exenson o*

07

026



066

RS/S o*

10

02

09

022

RS/exenson*

07

029

097

120

S/exenson*

08

028

10

6

xenson

Testing for Aberrant Gross Lumbar Motion Th uua racc hn in for abrran ro lumba moon  o  for ang f mn au h h may ax of moon by mnng h gr f n pbl from nural (uualy uing ann pour a a frn ba For x a a flxon ang of moion may b min o b 5° fm nural.  I non arlir h nl numbr  of  u a an ncao of ahogy r fr gung hauic xrc con Ohr lknown mak ar h nabiy  achi myolcc inc n h xnor a ful xion o  nabliy  ach full xn  fu 2.) Hor ahology may manf hn h ra an of moion no a n an an alo may occur n ax ohr han h rary plan f moon nrally hi ahooy  paab an in in ah ra moon cycl Th folon xaml llua hi on Th b ain n gu 22 ha nomala laral rang of moion an by rana  wul cafi a normal Yaurn bn  (fro nural 0° o 23°) y im h in bn laaly ain 7° a mall fxion cunk (nably f a r an a haf occu in h flxion ax. h occur y m h pn pa ° of laral bn Th on i ha h moon pahogy o inabiy wa n in h laral bn ax (or rma mon ax bu in h flxon ax (a cn ay ax Clinican ofn m h  ub abrran cach in h f ax un xamnaon Th mor kll clncan omm  hm  f hm wh hi han

Fexon eone e

Paologa

Noral

3D

3D

lumbar knemtcs

lumbar knematcs

60 40 20 : 0 · a -20 �  40 -60

60 40 20 a 200 �  -40 -60



a 100 80





  " /

 100 -80 Multfus

Multfidus

100 90 80 > 70 60  50 �  40 30 20 10 b 0

90 80 70 > 60 : 0 40 �  30 20 10 0 f

 g fl_ flexon /

ower erector spnae

Lower erector spnae

0 60 0 > 40 : 30 �  20 10 0 

80 0 60 > 0 : 40 �  30 20 10  0

Extera oblques

External oblques

4 2 10 > 8 : 6 � 0 4 20 d  

4 2 0 > 8  6 �  4 h 20

D

a (c

or oon rois r sho on h  ohr h EMG rns Myo sin s hv n h ubr xnsors  rn fl fxohis onsrs h ins n ss bly o br h o, ssn hy r in oo hlh. s l h bons r v o o on o o hns hr h n is holon i h boi  so s no o l  hn o h is in o  o h fxor o o  ino v or l fxon.his oo s  rkr o oo in n osrior s hlh.  iivu on h rh no uy x n is nbl o hv br xsor sl sl  h boinls r olly nln o v xrb h xo on rhr s  rv roubs n h osrior olx



(e

d

h

 ad

229

230

a

ow Bac k Disoders

65  7   �  O   21 5

Tl

1

terl e o the

' Fexo/exteo

 e  �  

b

 -2 -3   �  

 

d

1

er e

 2 -4

-6 3 25 e  � 4    2 -1

Axl twt

Flexo/exteo ervve



2

Figure 

4

6

8

1

hs i   o r o oo bu os  "isbliy  Du   b s (ro l 0° o vry i h s b y ssi 7° (v A)  sl xio  o  r   h o   lxio xs (v  his o vy  h s ss 7° o lr b hr s o vio  h is xs  boo urv rss  irs rvv o  lxo rv, hih  us o b lo sby h s (v ly ois o h oi  hih h isbiy our i h lxio xis  hs i,  us ivo  s i  rov  l o 

°

(c

a  d

,

n fiu 3  and , a lunk" o catch occus in h flxon xis s th pain flxs frwad and passs 30°; ts occrrd in v xion amp Somims pains will rprt pan as h catc ccurs and smims h iniian noi idn f muscl ctivatn buss bu  pain simpy mvs ouh  rion W us an lctmantic insrumn hat tracks hrdmnsiona spn moion and raphically displays  suls omims h cchs a so subl h i is far mor luminan o bsrv t firs drivv f h mtn axs wh t ch ain w pan hv a much hgr incidnc f ts catcs (McGl and P in pr) n normls indcang instablity Normals who dmonstt ts achs lthu rr may b  vad isk for coming patints accding o h brrant moon modl f Ricardson and collagus 999.

Testing for Lumbar Joint Shear Stability pts  and 5 offr a wldvlpd dscussion f th rol f  lumb xtnsor lonissimus acis and ilioosals lumbm) to suppor antror/posrior sr of

vutng the Pient

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35

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igure  In his pn n nsbily cch or "cuk occurr i h pry xs of oon (xion). s h fx, h cl ws s n h lxo xs  30° vn  hs occrr in vy ril o orw lxio h isbily is vn v B  h hr iviv of h fxio xs oio h hblion objciv ws o sbilz h spin o lin h cunk.his ws no uly sccssf ov h sho r. Sypos solv ony wh h pn vop spin poson wnss n ws b o vo lxon o 30



b

th vtbl tn sts. Ths sls siff st nsb n  h sh pln  ft  stbilizin xis st vlv ths sls A sip s  b pf t s  th pint hs pin pvk y sh instity n ths  bnf by n th  sh tn f h tst s psitiv th ptit wil  wll wth stbliztn xiss tht v nti t pt ts f h sh slt

Testing fo Lumba Joint Shea Stability Te pen es pone w e oy on  e  w e es ove e ee n e fee on e fooe pe son ms ex e oso mseTe nn en ppes e foe ownw ono e spnos poess n n ) sn  e sm en L, L4, L3, e) Unse semens e enfe wen ee e peson epos pn o e nn fees  se spemen  e pens epon of se menspef pn n s se s ven moe onseon Ten e pen s se o sy se e es o e f oo o on e  exen sos ) Te nn one n ppes foe on e spnos poess y ve of e nes of on e m

(cntinu

232

Low Bck Disodes

Mn sin fo ub Jon Sh Sbiy

(continue

exen sos w ee sen ns y  esen  If n s esen n e esn os on  en ses o sses w e ve oonon, e es s osve Ts es oves onsvey   vn e exenso s szes e se nsy n emnes e n Now e  s o nooe ese exenso moo ens no exese esons o  y ove o y ves

A Note on Motion Papation So liniians us thir hands t fl spifi rtbra otin durin ·hol trn oion sh as flin r twisting W hn thy d a bld" or stiffflin snt thy otn dlar i pathlgial and a it th tart f obiliin trtnt. Cliniians rarly hvr nsidr h ibility in th spinos pross d bony nral arh notd in haptr 4 Tw f y hD sdnts qstiond thr th sytri fl o a spifi join as tr pthogy r siply asytri ntoy prhps asyri fat jints (Rss Brzni and Mill 199 y rfully dou ning h tion urrin t th dis nd in th spinos pross in dari spins gthr with th applid lads (siilar t inial ads thy r bl o ntiy h fft f anaty. h rsuts dnstratd that or hlf of th oion flt y th linian as tually th spinus pross n nd bndin s iur 14 and not vrtral body tin. hs jints tht wr anilly sy r had asytri in ndr an applid lad fr th lnin. ratin sh a joint ith obilizatin thrapy wud  fritlss.

Testing for Aberrant Motor Patterns During Chaenged Breathing Th ts fr arant otr pats drin havy brathin is rathr sopisiatd bt it is about th ony ay t idntify a prsns' bility t intain spin sbility durin tss hat rquir hihr physlgial wr rats Candids fr hs typ of tst nlud athls and upational rrs sh as nstrution wrrs rhos poys and s n. W plrd h in bwn brthing and spin stability

Evaatng the Patent

233

80 70 60 50

Q �

40

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0 0

Atual eea i

10

u e eleti

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5

Fgure 

 fors wr pp o  p of  spious poss y iis o vi oo ss o  oo-ppo s Mos of  oo sr i  spos poss, w is w  li fs, oo p   spos pross i r  i  s Morov, syri oy s i sy oo w o o ii  l's  fos, sus  s s sol o  us solly o   s of oliz .

vusy (s 4546) Chlnge ethin uis hv invlvmnt f th mnl muscls ecuse we mn he muscls wih MG elecds n b cuse uscle iue chnes the EMG snl, we v cetn hevy lun vnltn with ecis f hs ts. e th this cnsiein s nly f tsin nd ht w will inentnl incs the hsic w e  ciss in ch 4

Breathing Test

CO

n s es e peson eaes a 0% as mxe o eevae e n venaon w ony a few eas  e s ajse so a e eaeness a aom panes ypevenaon oes no oen a we  s ay ao 15  33 ) fo e aveae man , s pae n e ans we e oso s fexe fowa ao e ps o appoxmaey 30°. s es eveas ose wo ave ae an moo pae ns n e aomn as n aene ea n a ompomse ma sa y



23

Low Back Disoders

Goo sine stailization atterns observed in the usce EMG sinal obtaned dur ng the challenge reathing test inclue a constan usle cocontration ensurin sne stait Fgure 25 shows stae ttes a an unstae ttes . Our couterize anasis ackage easures sine stabit using the ethos exn in chater 6 Man clinicians will not have this caailit ut shoud stil look for constant levels of aoinal wal activation atients ho are oor at stabiliation in these situations ill eonstrate short teorary reuctions in ativation or ven oss of ativation These ark the ctical instances at which sine instbilit can cu nd classy the erson as a caniate for sine stailization ung high hsiooial ork rates These atients ust learn to contract the sine stabilization uscles indeen entl of challenge reathing to ensure sine stailt in conditions of hvy work

Determining Suitability for ROM Training and Strtchg The McKenzie extension aroach is wellknown for treating acute isoeni troubles he extension ostues can also e use as a test to ienti those with osteor disc toubles Ticall these osteior iscogenc atients shoul never x th luba sne hen t is uner sustantial oaing

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Goo sp sbzon prs urin  CO bhi s nu  os usl ooon wih nsus sp sbiy. Boh sb wi os s vio  sb vrb boil s von ps  show



b

60

Evauating the Paent

23

DcKenzie Postue Test Te paen ens n a eaxe sann pose, an e nan ass m ao  en pan an e en ea feen ao e a Ten e paen es pone, aopn one o e oown ee eves o e MKene pose po esson (e nan e es w s sae ase on e paens fexy an sympoms

  

one w e ams eaxe (a one w e n esn on e ss ( one sppoe on e eows ( If e paen anno oeae one o ese poses e  nan an assme a smpe s sanes ae no e soe o oes o a eas no e so e soe Many w nompae poseo s esons o enaons fn eef n ese poses Te paen en ens o e sann pose f e fees moe sae an/o as ess pan ompae o e mo mens po o yn pone, e s assfe as poseo soen

Ptints wo  ostrior dscogenic sould void exon stretcs nd  flxd sine under lod wen eforn xrcis ter. Tos o fl wors uon stndng could v  ost of oter ossibl condtions t ill robbl xrince bettr orss b dotng  neutr to slitl flexed lub ostur for exercis ter.

23

Low Bak Di sodes

Distinguishing Between Lumbar and Hip Problems ain in the tck an/r raaing n the eg can have re tan ne sce r ectiv teatnt,  st iscver hethe hat srce is in th ar sne r n te sacrac SI nts, in varis scles r in tisses arn the ip r even e hp nt ise

l Test Sevea foms of e sn smp es an e se o e aan sa sympoms Tese ae esne o ense e sa neve an ae e ma neve oos Typ ay e paen ss on e ae o a an en smps o soes Te nenon s o poessvey nease e neve enson Ten

  •

e e an en e exene a e nee (a ensn e neve fom eow e ma spne; foo fexon an e ae ( fe ensn e neve; an nay e neve a n e fe ens e om aove e m a  eon w e aon of eva spne fexon (

If e enson a any of ese saes ases sympoms fe poessve esn s soppe an e paen may e a anae fo neve fossn (ese n aper 13 Cerany fexon w e onranae for ese paens n sen an exese

I leing te neck es n increase the ain then t sciatic nrve is nt t issue  inerest an the clnician can egin assessing te SI nts e asrins irirs, an the usclease snres ening ih t ip

Test Te Fajesajn es so aways  e pef ome o n o es even wen e saa s naea Rasn e "we e" s neee o pefom e "we e asn es of Fajeszajn" (eama an Roman 970. Rasn e we e ensons e neve oo on e we se o ee w asn ensons enay aon e m ne of

Evaatg the Patet

23

e aa eqa a  e eve s  e pp se se (a Smemes p a s pve w sm a es eva fex ( a  e sympma se (se  ase s a  a s f s es  say a me ea es I s  a s f mae as sme ave sese 

I m continully surpse  the numbr of peope with bc roubes wo so h ve hip toubles (McGil n colleges in press recently note  corltion between bc toubles n hp thoogy in fcoy worers I is sometmes ifficult to seprte hp pin fom lumbr trobe snce beep butoc in cn e scitic (lumbr) or oiginte in te hip oint Tyiclly, meil n nero hgh in e inictos of hip pthology If hip tests re inicte y the nerve tenson ests escribe in the previous section (e. they wee negtive, fexion n otton tests shoul be performe.

F exion and Rotation Tets y spe w e p fexe e pae's  see s ae  p ea a (a Sfess  pa s a ps ve a f p es Hp j pa s sewa s ve w aa   e  a/ a e  a ease a/  ea/ae  e pae's p s e fexe ( we e ee s ve  a ms s e aea  w e ee e s as   fse ay pa w eve es eae  e a

2 8

Low Back Disordes

References 1984)

Biering-Sorensen, F Physca measrements as sk ndicaors fo lowback troue ove a oneyear period. Spine, Deama AF, and Roman RH Te intervertebral disc. Piadelphia W Sandes McGi SM Cids A and Liebenson C Endrance imes for stabiizaion execises Cincal argets for testng and tranng from a norma dataase Arhive ofPhyia Medcie and Rhabitation McGi SM, Genier, S Pess R, and rown S (in press) Asymmetries n torso endrance and srengt parametes are associaed with a isOY of low ack roes McG S M  and each ] (n pres s Electr omyogra phic and spine knematc canges wth pain

9: 1119 97)

1999)

8: 941944

Rchardson ,  G Hodge s, P and Hide s ] Therapetc execse for spina segmental stabilzation in ow ac pan Edinrgh Scoand: Crcil Livngstone Ross ]K, Bereznick D and McGil SM Aasaxs face t asymmety  Impl catons fo ana papaton pine

1999)

4 1): 119

1999

Developing the Exercise Program

T

he xecises escie in his chate comise a oam foune on the in ciles iscuss in eious chates his oam is sufcient fo many atients an fo those inteeste in otimal ack health. Fo those ith efomance ambi tions, chate 14 offes moe aance esions hile I claim no extise eyon the lo back, I ill oach othe issues tha hae imlications fo the ack Fo exam imo technique hen emin hi an knee moilization an stetching can comomise the ack fo his eason  hae inclue them h Uon cometion of this chae you ill e ale to esin execise that challenge muscle an estalishes stailizin moto attens, ut saes the sine he focus he is clealy on he atien an lo ack health fo eeay actiiy

Preliminary Matters Befoe esenin the excises, I il eie some of the asic ieas iscusse in th text thus fa, estalish ho to sech thout stessin the ack, claiy issues ea in abomina holloin an acin an intouce he technique of fossin th neve oos fo those ith sciatica

Philosophy of Low Back Exercise Design Many aitional notions hat execise ofessionals consie to e inciles fo ex cise esin, aticulaly hen ealin ith the lo ack, may no e as ell su ote ih ata as enealy thouht. As eiously note, many clinicians stil e sibe sit-ususualy ith the oiso that the knees emain ent. The esultant sinal loain of ell oe 3000 N of comession to a ully exe lumba sin laly shos the folly of such a ecommenation. Othe xets still ecommen the osteio eic tilt hen efomin many tyes of lo ack execise his actually inceases the isk of inuy y flexin he uma oints an oain assi tissues he ecommenation of fattenin the luma eion to the oo hen fomin

239

240

o Ba Dsorers

adna xcise s anthe sin of this ilond phlsphy Many cn ne  bli that han stone back an aboina  sls is potct ad eds bad bak eisoes een thogh Loto an colags 99 ang ths showd that  sle , no stength, is e pte. hs shold no be sntped to ean that haing stg sles is not a gd ob; ath t ects on any o he stngth taining appoahs enly sd that at ack patints. Myths sll ean gading the ne f gat lba lity whih the dn sests leads   bac tobsnt ss g ieing Sensn, 984 Finaly we a distbe by the fact that pliating h  and spn lads hat occ ng th se of  any lw bak xns ahns se o ann an heay dcd ds heniaons whn appld to spns in  laboat Clinica l Wisdom

Claly s ent clnal wisd nees t b xand n h light o th sinifi iden h o whh has ben pesene in this bk Ths dn ss to inda hat he saest and os echanialy jstiabl appah t nhaning lba stality hogh xis s to ehaiz ndan  stngth Clincans sng sh an apoah shd encoa atens  aan a nta spn pos when ne loa and se abdonal cocontatn and bang  a fntioal way The boybilding appach often sd n hablitato is n synnyos wh halh bjetis and eslts n aiinal isk  at nt lading hgh a ane o otn and the often sp t pats that a nt pial f nsin nt stabliy.

Saring the Back While Stretching the His and Knees

Gn tha spass in he soas whh podc a shoening and hp xnson st ion, a n in hose with bak tbles (Gene t a, n pss, ths pl wold pbably benefit f h stthing and the ang-of-tn xss o ties, hwe, po techne whn stthng hi an kn tisss lads o nn ssay oading f th a sn This an asly e aod by hangng thn A gnal gidlin  spain th bak is t ainain an pght ts pst while png hp an knee wok Psation f a ntal spn nss nial load ng o passi sses An pight tos nizes h atn s th ass atd  s ontaction an sn load Abdoinal aing is ss d f pain ontl. F xale lges a a gd xecse fo chalngg stngh end anc baan an obty n h lw xeties. Lw xty apabilty s neeed t altae spine-spaing psts whn litng and whn pfing a hst  h tasks. the Back

Th thni o sain th bak s t antain an pigh ts ps whl pfoing th ln (see fig 3  e linicians ed kping th bak g staght which ases patints to lex h tos fwad. his is po o f spaing the bak (s fig 13.2. A neal pnipl s  kp th tos pigh wih a nal lba spn whl stething jins h han h bak

Deveoping the Exerise Program

241

Figue 33 fo exale shos oet ostes fo stething the qads (a) and the hi autos ( Finally he lnge ih a netal sine stehes ilias oe han soas (liaus is a uniatia  sle tha osses only the hi) Ful steth on he soas eqies a lateal end of the toso aay fo the extende hi bt this is eseve fo the oe os aks see fige 3.4 a-

Fgu 131 The spne s spaed performg he unge by manang a upright orso and a eua spie cuvaue

Fgu 3.2 Some clnicans recommend keepg he back eg sraigh whle performig uges, which causes patents o fex the torso foward This s poo fom for spang the back

Fgu 33 Dug sretchg a jonts othe han he back, he spe s spaed by maitaning he uprigh orso and neua spe curve Whe seching he quads hoding a chair fo baace s a good way to esue a sragh back a he peson shown n(b) has suffcien hp fexo mobiy o ensue an upgh oso and a euta spne. Indivduas who ae unable o maan his spine posue shoud forgo hs exercse uni they can acheve the requed hip fexio mobity

ontn

242

o Ba Disores

Spang the Bac

continud

Figure 134 Gve e uaicuar liacus a e uartcua psoas at cosses the hip an eie uba spie, a ue psoas stech equres he oso o be aeay ben away fo e exene hp; s s a avance stech fo he oe obus backs.

Flossing the Nerve Roots for Those With Accompanying Sciatica Beoe esenn e ossn tecnque o scaca some backound s equed ean e omecancs and ocemst o te snal co an neves Ecessve tenson n te neve s te cause o scatca Nomall te cod neve oots avel tou te oamenae o e neua ac o eac veeba, an te sn ecusons ae sustanta wt sne eon  eon an knee etenson Accon to Lous 9 te nee can avel well ove a centmete ove 2 n dun some o tese movemens Tus  a nee oot s mne an cannot sle an o ese ostues tat wou nomal ull at nee oot toug te oamen wl ncease nee tenson Insea o movn te neve s stetced. ute tenson on suc a neve can e nceased om te canal en wt smultaneous cevca leon ecause te ente snal cod moves sl wt cecal leon and tus ulls at te neve oos al alon ts lent Ts s te ass o te slum est o nee tenson esente n cae 2. Recentl scentsts ave sueste tat nees ave te al to ceae te own atwas as lon as e can move Te seem to ave some cemcal based alt to ssoveove tmetssues mnn tem Te ea o lossn s to ull e cod and nees om one end onl wle elean at e ote and ten to swt e ullelease decton In ts wa e nee oos ae ossed tou te latel

Dvoping t xrcis rogram

243

oamna and n at alon th nt lnth. Thus  wokn th ns ak and oth n whatv mtd an t an mana n spt o mpnmnt w altat th dssolvn o th mnmnt and th adual las o th n to on an mov  (ths apoach was oposd  Butl 999. hs lossn aton s accomshd wth coodnatd h kn and val moton

T an, sa an w  s a o swn fry, fxs  crvca sn (a). Ts cras a u on  sna cor from  crana n an a ras from  caua n. Ts sou no rouc scac symoms (s  scusson of  sum s n car 12. Tn,  an xns  crvca sn w smuanous kn xn son on  s w scaca () Ts us  nrv from  caua n w a corr sonn ras a  crana n. T cyc s com as  kn s fx w coorna moon of  crvca sn fxn.Ts causs  nrvs o foss rou  vrra ssus. f  an xrncs mnor scac symoms wn  crv ca sn s fx or  kn s xn n  sou ruc  ran of moon a s jons un no an s rovok Som ans wo av sur scaca an for yars ror rucons n r scac symoms wn a fw ays o a cou of wks; ors ror ncrasn symoms A no of cauon s n r: w s can  wonrfu n n cronc scaca rsouon,  can aso caus an acu ons  very consrvav n  frs ssson If  nrv s ar so a  can s,  scac sym oms w  xac ra. Howvr, f  an rors no can or vn rf  nx ay, n roc o ncras  fossn. W av no n a o uncovr a rocur a rcs wo w o w or wo w  xacra from s fossn rocur. Monor a ans an rmov  rocur from  rorams of any ans wos symoms worsn.

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o Bc Disorrs

Exercises for Training the Stabilizing Muscles Ate  bre evew o the musces th stlze he sne we wl hve  look  eercses or rnng those musces

What Are the Stabilizers of the Lumbar Torso? Whle mn musces hve been regrde s rm sne stlzes conrmton o her roe eques two levels o nss rst engneerngstbl nlss must e onducte on nomcl robus sne modes to ocument he lt o h com onen to sten nd stze Second electromorhc recordns o l musles even dee musles requrn ntmusur eeroes) e neessr to onrm he etent o whch the moo contol sstem nvolves eh musle o ensure suent stt. Ou ntmuscur n surce EMG n moelng studes o qun sne st l emonstred tht vull ll tors o muses l  ole n stbzon. (Some dt ws resented n chter 6 ) Whle multus the other etensos n te bdomn wll ll e to l sgnnt roles, he qurtus lumborum lso es to l n mont role n mn tsks The bers o qudtus umborum rosslnk the ertee, the hve  lge lterl moment rm v the trnsvers ocess tchments n he trvese etween the  e nd lc rests. n ths w the qudrtus butresses sher nstlt n ers to be eeve n ll lodng modes  ts rchtecu desgn. Tl the s moe o lum buk lng s terl the qutus pes to l  sgnnt rle n ocl lterl ut tessng. The three ers o the bdomnl wll e lso morn or stblt togehe wh the musces tht tch recl to veeethe mulsegmented longssmus n loosls n the unsement muld Choewk nd McGl 996 lso resented n gument o he ole o he smll nernsvrsr n rducng smll ut ccl stblZng ores On he other hnd, sos tvton ers t o hve ltle reltonshp wh ow ck demns the moor onro sstem ctvtes t when h leor moment s equred see Andersson et . , 199, nd Juke et . , 199 comomsng ts ole o stblze he spne when h eon s not nvoved. So whh e the wses ws to chlenge nd trn these ented stlers? hs queston wl e nswere n he olln setons

Training the Stabilizers of the Lumbar Spine: The "Big Three Qunve t hve conme h no snle bdomnl eerse chlenges ll o he omnl muscultre whe srng the bck (Aler n McG, 997) For ts eson more hn one sne eercse s requred nounte, mn nrore eercses hve oten been escre or peole wth ow bck dcultes nludg he olowng: •

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S-us (boh sthtleg nd benknee re chcterze b hgher sos t vton wth consequent hgh ow ck compressve ods tht eeed OSH ocutonl gudenes Le ses cuse even hher sos cvton nd sne omresson tul vlues were resente n chper 4.

Deveoping the xercise Program 245

Upp  Lw ct ? Myoctrc idnc normal an calbratd susts tat tr s no nc tion istinction btwn n "upr n "lowr rctus bdominis n most opl; n contrast, t oblus ar rgonally actat wit ur and lowr nuomus culr comartmnts as wl as mdial an latra comonnts n our institons w mad sr rlnt osrations rgrding psos c tion durn bominal xrciss. T cln to t soas is lowst uring cur-ups follow by ir lls during t orizontal sid rig. Bntkn st-ups wr crctrd by lrgr psoas ctition tan sraigt- sit-ups and t gst psoas actity ws obsr un g raiss and n-on-kn flxor isomric xrions T oftnrcommndd rssls stu wic as n yotszd to ctiat mstrins n nuraly inbit psoas ws actuly confrm to ncrs sos acttion! S igur 3.5 ) Orinal at can b found inJukr t l1998 som clincians and cocs wo intntionaly ws to trn sos will find tis data informti ) Onc aain t orzontal sid suport appars to  mrit as it calngs t ltral oblus and trns rs aomins wtout g lumar omprssi lodin nd nsurs a ig stbity indx  oss o contraction of t inold muscls woud cus t atnt to fall out of t bridg) A ws coic fo stabilzation xrciss in t arly stas of trnin or rbilittion, nd or simpl low back at obcts woud b t bg tr tt w  uantii to suffintly Figure 5 The pess-eels st-p was proposed by callng muscl sar t sn of ig lod nd sevea inia goups, on theoetal gounds, to nhibit psoas by ativatng te amstrings In fat, nsur suficnt staity: eletomyographi assessment (Jker et a, 18 poved ts to be mytiahs srcina photo fom the ntramusla expeiments sows te inians' hands behind the hees of the sbjet as they ativate amstngs dng te sit-p Ativatng the ham strngs eates a hip extensor moment, and st-ups eqire p flexon Du ng this type of stup, the psoas s ativated to even ghe evels to oveome the extensor moment fom the amstngs and pode a net fexor moment Tis type of st-up podued the gest evel of psoas atvation of any stye of sit-up we qantfied!

Training Reus Abdominis

. Cur-ups for rctus bomnis 2. Sral artions of t sd brdg for t olius transrs aomins nd udrtus 3.  an arm xtnsions dng o progrs sions of t irddo for t many bck xtnsors  aration o ac o ts xrciss must b cosn wit t atnt/att's status nd gos in min.

Clibrt ntramuscular an surfac EMG idnc susts tat t arous typs of curus callng mainy rctus abominis sinc soas n bomin wl intrn and xtl obliu an transrs bdominis actity s rlaty low s tbls n cptr 4 for rati actation ls in a arity of xrcis tsks. Curl-ups pr orm wit oor tcniu owr can b countrpoducti tr ing to

246

ow Ba Dsorers

Figure 13.6 Poo fom dug he cuup s o fex he cevica spe oadig the ec ad o he ecus a Coec techique focuses the otaio i he hoacc spe ohe commo ype of poo fom is o eevate he head ad shoudes a lage dstace off the floo (b). hs pae is eevag fa oo much which is close to epicag he much hghe sesses of he sup. The ieo s to actvae ecus ad o to poduce umba spie moto.

tt t ctus bdoms sufftly o stssg t sp s fgu 1  d  Cl-ps wt  twstg to  xps  ts of lumb pss du to t ddto oblqu llg Hg oq tto wt lw sp od s ccomplsd wt t sd bdg wc s tf fd  twstg ul-ps fo tg t olus Ts wll b pstd  t  st. T gstll ulup wl b pstd  pt 4.

Beginner's Te curu ecnque s crca o sare e sneTe basc sarn osure s sune w e ands suorn e umbar reon o no faen e back o e foor wc akes e sne ou of easc equbrum and rases e sresses n e assve ssues We e oson of easc equbrum s desred n e umbar reon e ands can be adjused o mnmze an f needed One e s ben w e knee fexed o 90 we e oer e remans reaxed on e foor.Ts adds furer orque o e evs o reven e umbar sne from faenn o e foor. Te focus of e roa on s n e oracc sne; many end o fex e cervca sne wc s oor ec nque Raer cure e ead and neck as a rd bock on e oracc sne. No cervca moon soud occur eer cn okn or cn uckn ndvduas wo re or neck dscomfor may ry e somerc exercses for e neck a foow. In add on arcuary for aens exerencn neck dscomfor e onue soud be aced on e roof of e mou  bend e fron ee wc es o romoe sab zn neck musce aerns. eave e ebows on e foor we eevan e ead and souders a sor dsance of e foorTe roaon s focused n e mdoracc reon. Te ead/neck s ocked ono e r b cae. No cervca moon soud occr eer cn okn or cn uckn T e nenon s o acvae recus and no o ro duce sne moon

Deveoping te xeise ogam

247

A vey m fom of e cuu s o us ake e we of e ea an soues w amos no moon (a) we moe caene s oane w asn e ea an soues u focusn e moon o e oacc sne () w no cevca o uma fexon

Tose wo exeence neck symoms w cuus may fn eef y un e neck w somec execses n a of ese execses e ea/neck oes no move an e onue s ace on e oof of e mou en e fon ee (a) e ans ae ace on e foeea wc esss neck fexon effo ()eeae e anon s e ace onse; e se of e ea o ess cevca se fexon eo an en oe (c) e ans ae ace on e ack of e ea o ess cevca exenson efo Ho fo sevea secons en eax un u enuance an oovn sazn moo aens y nceasn e eeons of e o/eax cyces eeve  o no some aens y s we cewn um wc makes e oovn of sazn aens mosse)

248

ow Ba Dsorers

Te nermeae roresson of e curu s o rase e eows a coue of cenme ers so a e arms o no y e sou es u, us sfn more oa o e rec us. o no rase e ea/neck any er an n e enners curu.

�p,Advanced An avance curu requres acn e fners y on e foreea (never e n e ea, wc causes e enency o an osure fex e cevca sne),an as on as u umar s conroe no ressure s ae o e ea y e ans. NoeTe aveae aen nee no o o s eve f sne ea s e ojec ve. Te ea an neck mus move as a  un, manann e rock oson on e oacc sne.

Training the Quadratus Lumborum, Lateral Obliques, and Transverse Abdominis Gv h archtectural an elecomyoraphc venc for he quadrtus umbom, tansverse aomns a aomnal oliqus as se sabiers th pmal thu to maximiz acvatio but mimie th sine ad apears t be the sd bdg Aomal baci s emphase  all oms of ths ecse. Matng th bdg nsures cosa muscl actvaio whi the brac roucs nw combin tons o muscle recrutment o esure stabliy. It is almost impossbl fo th sp t cm unsal whie eromg a se brd wh a neutrl s

Developing the Exercse Program

249

Many seca aen cases deserve consderaon-for exame, e cronc aen wo s que decondoned.Tese aens are somemes unabe o erform e sde brde even from e knees. Sar ese eoe w a sde brde we sandn aans a wa. Isruc em o move smooy from e bennn oson (a) rou e nerme dae osons (bd) o e fna oson (e), n one fown moon.Te aen soud vo over e oes as f erformn a fud dance move.

Once aens raduae o e foor ey can sare e sne by bennn w e knees and s qe fexed (f) and movn no e sdebrde osure w an accor donke unfodn of e es a e me keen a braced neura sne ()

Anoer ye of aen s e fooba ayer wose souders are so anfu e can no oerae e souder oad (some edery women aso fa no s aen rou) Tese aens can erform a modfed sde brde by yn on e foor and aemn o rase e es aeray ( and ) or smy aemn o ake e we of e es

ntine

250

Lo Bac Dsorers

Side Brdge, Remedial

continued

Anoer oon for aens  souders a canno oeae oad s o sand on a 45° enc  e fee ancored U} c sares e souders

sn oer devces, e orso can ee e eevaed from e ad (k and I) or rded  e souder (m).

Deveopng he xerse Program

251

Beginr's enners brde fro e knees In e bennn oson e execser s on s sde,suored by s ebow and . Te knees are ben o 0• acn e free and on e oose soude and u n down on  w e sabze e souder Te oso s sraened un e body s sored on e ebow and e knee, w soe nu fo e ower e. Te benner's sde brde can be sy advanced by acn e free ar aon e sde of e orso-efecvey acn ore oad on e bde

Intermeiate e bennn oson for e nered ae sde brde s ke a for e benner exce a e es are sra Te orso s sraened un e body s sored on e ebow and fee (See fure) Wen suoed n s way, e uba cores son s a odes 2500 N, bu e qadaus coses o e foor aears o be acve  o 50% of MVC (s s a referred exercse for e obques snce ey exerence s ar eves of acvaon)

252

o Bac Disorers

ntermedia te Variation acn e uer e/foo n fron ofe oer e/foo  enabe onudna"ronof e orso o caene bo aneror (a) and oseror (b) orons of e abdomna a

Advanced ecnque o enance e moor caene of e sde brde s o ransfer from one ebo o e oer wekn abdomnay bracn b and c) raer an oson reea edy e s o e(a,foor no e brde nsure a e rb cae s braced o e evs and a s rdy s mananed rou e fu ro from oe sde o e oer. S er eves of acvaon woud be reaced  e fee on a abe surface (VeraGarca, Grener, and McG, 2000

Deveig the xercise Prgram

253

Training the Back Extensors Most tadtonal extensor exercses ae chaactezed by vey hgh spne oads, whch reut rom extenay appie compessive and shear oces (ether rom free weghts or resistance machines A commny re cbed spne extensor musce chalenge n volves ying prone while extendng the arms and egs (see fgure 13. 7. his esults in over 6000 N o comresson t a hyrex tened sine, transers oa to the facets an crushe the intespinou ament. eed le to say thi execse  contandcated for anyone at ik o low back injuor einU! Athouh some may v that puttng the han on either ide f th head ather than extenng them may make ths exercse sae that is not tue It shoud e not be done n any om. Fher ecal that the mechanim o dsc hernation s rer uced y ack machnes that tak the um bar spne from ful lexon an thrugh the Fgure 137 A commony pescibed spne extesor muscle rane o moton under load from musce calege ivoves yng poe whle exteding e ams and legs. contacton This resuls n over 6000 N of compression o a hypeexeded In ou sarch for metho to activate the spine. I s a poorly desgned execise. extensors (incluing ongssmus costa and mutii) with minimal sine oad ng, we have found that the nle leg extension hold eut in toeae spne oadng «2500 N) or many and actvate one se of the umba extensors to apximately 8% of MVC. Smutaneou e extenson wth contraatera arm ase (the "iddog inceases the unatea extensor muscle chalenge (approximatey 7% MVC n ne se o th umar extensors and 45% MVC in the othe se o the thoacc extenss ut aso increase umar compresson to we over 3000 N (Calaghan, Gunning and McG, 1998 Ths exece can be enhanced wth adomina ran and delierate menta magng of activaton of each eve of the oca extensors. Once again, teh nique for chaengng the extenors shou be uided by the patient' status and goals Ths s an ndvdua cnical decion Cncians shoud remember to emhaze abdomina bacng and a neutra sne thrughout a vesons of th exercse. Poor form nclue h hkn o any ther confguraton that causes devation (twst exon o latera endng to the sne see gure 138, a-.

Figure 13.8 Commo msakes made n e biddog are "hikg" te ip, whc wiss e spie a o no achieving a neural spe-a flexed posture is seen in (b).

25

o Bc isoes

Remedial e sn oson s on e nds nd knees  e nds unde e soudes nd e knees decy unde e s (). Fo e en   vey decondoned bck s execse nvoves sy fn  nd o knee bou n nc of e foo (b) fe e en s be o se  nd o knee ou n, e cn oess o sn e oose nd nd knee suneousy.

Beginner's e oesson connues  sn one e o one    e

Intermediate Te neede bddo s ceved en e en s be o se e oose  nd e s uneousy soud s n ee e He  o evod e s ozon. Te objecve s o be be o od e bs e o e foo fo bou sx o e seconds Good fo ncudes  neu sne nd bdon bcn

Deveopng the Exee Pogrm

255

To deveo e moo onro ene furer, e en oud no re by n e nd nd knee o e foor fer e odn reeon. Rer f er exendn e norm brddo o on (, e oud ee e foor  e nd nd knee o  no e  borne by eerTe en  on be nnn e ee (b, ( o m  e nnermo on of e eend (d o m omn bk ou of e ee. e en en exend e ve mb bk ou no e brddo oon (e  enque o o mue o reoxyene  e "ee ye (MG, Huon, nd k, 2000).

256

Lo Ba Dsorers

Beginner's Program for Stabilization Nw that yu ae fama with ome specifc ecommn lw bak xiss hw  you put hee tgehe  ceat h t posl pgam f yu patint? W mmn conng th follong quene: 1. Begin wth h exion/xensn yc alo calle the cat/am on s figu 3.9 a an )  uce spine vsy ot that th t/am s nen a a moton xce nt a ttch o th mphasi  on tn ah han "pushng a h en an of fxon an extensin e hav foun that fv  x cyl ae oftn uffient t uce mo vsus tssanal yls aely euce visu fton futh. Ths wh catia may fn nas yp om uing th flexon phae Us pain to gu th suiabl painf an f mon 2 Slow lunge wth an upgh an bac too satsfy h btvs f span he spin whi ahivin h an knee enuanc an mbity s fiue 3. 1. 3 Sciats may ty the neflon techniqu 4 hs motons ae folow y ant abmnal xcss namly apppi a ul-up 5 Laal musulau exe flow namly th si bie f quaus umbum an th musl of th aomna wall f optal stabiy 6. h xtno poam ons of lg xtnson an the b In gnal we emmen hat he smetc hls fm n h ul-ups bs an b  n longe han even  eht scon, gven nt vin fm na nfa ptcoy niang ap os f avalab oxyn n ts muss ntatingan at ths axaon bjtv f the mus ss xyn (MGl Hughsn Paks v. 2000 ShO he enuance ae achiv by buln up pttions f the exton athe han by inang th uatn f ah h Motvat y h venc fo h supeoty of xtns nuance v stnth as a nhmak f go bak health w ently oumnt nma ats f n uane tm fo th too flxo latve to the extn an lata usulau (s hapt 11. U the valu t ny enuanc fictbth absut vaus

Figure 139 Cat/camel exercise. Note tha his s a moton execse and no a sech; do no push a he end ange of motion Vscosy s measably educed afer js a ew cyces

Dvoping t xrcs rogm 257

nd o one sce rop retie to nothend to eslsh resone endrne os or yor pents

References Anersson, EA, Odsson , Gnstrom, M Nisson J, and Thorstensson, A (996) MG acivties of th quaatus lmborum an eretor spna mss uring fexioneaxation and oher motor tasks Cinical Biomechics  1 : 392 400 Axer , an Gi, SM (997 Low bk oads oe a arity of abdomna xses Searcing for the safes abdominal chaln Mdicie d Scic i Spo ad rci, 29 ) 80 4-81 1 . Biering-Sorensn, F (984 Pysa measremens as risk indiators for owbak troube oer a one-year period Spi 9 069 Bte, D.S 999 Mobil zation of th  nerous sysem  dinburgh, otan Ch rhi iingstone Cal agha n, JP  Gnnng, J., an MGi S. (99 Reationsh between mbar spine oa an ica Trapy    8 -8. ms acity dring extnsor exeses Chowck J , and Mc Gi, SM. (99 Mehana sabiity of the in io lmbar spine Impcations fo inju an hrn ow back pain Clinic Biomchanic   0): 5 Grnier, S, Pess H Russ c and McGil, S (in press) fits n a wi ariety o itnss ariabs ing aftr ack roube psoes  uer D, G, M Kropf 1'. an Steffen, T 998 Qantitie ntamscar myoeectric activity of mbar poons of psoas an he abominal wal during a wid arity of tasks Mdici and Scinc i Sport d Exrci30 2) 3030 Aaoica Ciica 3   ois, R 98 Vrtbroadar and rebomular dynamics oto, 5 Heloaa ra M, rri,   and Aar anta, M  (995 Stai a nuane an te sk of ow ba pain iica Bimchic 0 323324 Gil SM ghson, n an arks, K .  2000) Lumba ereor spinae oxygenation uring po onge ontrations: mplcations for prolond r rgOoic 43 486-493 000

VeraGarcia, Grene, S.G, and McGl, S resons uring -ps on both Phicl Trp80  Aboina sa an.., ae srfaces 4-569

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Advanced Exercises

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he begnne's rogram desbed n hater  shold be sent or aiy sne health Several sitatons hoever may al or rther training:

Cetain oaonal tasks wth sei emands tha reqre nqe reaaton an tranng ome athleti tha mh deman hgher o orom bak ranng alhogh ths sendeavors aheved wth hgher rskhallenges o tsse damage overload Some aents ho as they rogress h he somer stablzaton exerses esrbed n hapter , want to ontine nreasng the hallenge

Ths hater ll dsss how to inrease o bak hallenges saely o to a dress se orker and athleti onerns egardng advane training an soe deas aot he nex steps to e aken n he sdy o lo bak stably Upon omleon o ths hapte yo ll be amlar with some gelines to rsrbe exerse tha ll enhane perormane n a ay that sares the sne A oe omlete book on his o s othoming rom the ahor

Safely Increasing Challenges To otme atient saey the linian mst be aware o sses assoiae i ranng on able sraes and wth mahines an how to rogress the "bg three exrses desbed n hapter  (rs se brdges and e and arm extensons to thei hghest level Some gdane s rovide hee

Labile Surfaces and Resistance Training Machines Not all lnians are aware o the ators they shod take nto aon hen eing hether to presrbe exese sng aie sraes or mahines Follong are gelnes abot boh o hese sses

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Low Bac Dsods

• Trg wh ll srfs Chlngs o  sn rng iy viy n c mainnng sbly ng s saysa osus; unxe long ns n nn ynm o bals movmen Ths hs mova some ln cians o rcommen xersng on bile sur facs suc as gym bs. Cenly es ble suaces challng he moor sysem o me  ynam sks o ly lving or si c acivs n n be ve ll for avan inng. Bu mgh his ye of aining b of onrn or som ens? Or rcn qaniion o elev sn los an msl covaion hn forng  curlu on lble sures VerGr Gn, n MGil  sggess h  h hblaon ogrm shol begn on sle srfes. In is s we assesse he sle crl or he eff o  labile surfe on mscle cvon erns see fge 4 a) Simly movng om a sble srfe o a bile srfe cus mch more ooncon whh in mny ses vrully oubl  sn loa se fgre 42 he racie of ing ens on l sues arly n h hbve ogrm n ely

mrovmn by casng exrbng loas. W rfoe sgges begnnng sne xercss on a sbl surfe n esblishng  osive soe o mrovmn nro labile sfcs iciosly only on   n s aciev sne sbly n suf cnly resore loberng y n can ol ionl omresson. hs sam ncl cn be xene o sng Sing on a gym bal grely eevs sin loa ough inras msle ovon For his rason nonns sho vo rolong sng on gym blls n aens soul se hm only once hy hv achiv sne sbiiy n nese lo aring ciy Thre s a ime n  le for lab srfes.

Figure 11 he sipe cr-p was assessed fo the eect of a abie sface on sce actvaton pattens. he percent of axia vontary cotrac tion (% MVC) n the rects abdoinis and extena and ntea obies cased by spy ovig fo a stabe srface (a to varyng types of abe srfaces b  and d is show  fge 

Advanced Exercses

50

• Trg wh mhs  qpm Genely e gol o e lng lzng moo en e qe e nvdl o o body weg n coodne e blzon o l jon nvolve n e  In oe wo    woeoy even oeeon enevo Mny nng mcne on e oe nd e me o oe  ecc jon. Snce nee

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d

Pou hon n ur 4

 Ru bdomn • E obqu D n obqu Fgure 14.2 The % MVC caused by each o he postures sho in gure .. A cu-up h he body over a ba ad the eet o the oor (igue c) vruay doubes he abdomina musce actvato seen n a cu-up o a stabe surace (gure .a) and, corespondngy he spe oad Noe that he % MVC euired o

the three musces studed s aso much hghe n cu-ups th the body over a ba and the eet o a bench (igure  b) ad th the body o a obbe boad (igure d) than on a stabe suace. Ceay a gym ba can be odeu or advanced traiing but s contradcated or may patets

oe no ee eom e  n  cy lze mnne ee ye o moo en my no e nele n woe my ce no e goovng o moo/moon  en. Te ony me mcne  oe jon cn e el  wen n njy o  ecc oy  eqe  oecon dng eblve nng ome ncoecly eeve  ong  on omeow ee e lodng nd  ece e  Cone o ex me e yl exeno bene o Romn c w genelly moe wce e mle ong n e om eomng e og ne bo g nd e de o e lm n e occ exeno e cved ee ge  Pen wo m e m cne ol cone cen  ng ecnqe Te eg e c o exmle omeme ce e elv o oe wy om e c e wen e weg  lowee (ee ge  Te eln mb exon oce enng conon  o e dc!  en m e  exece we gge ey e  one leg   me o ene  e ev emn n onc w e c  nd  ey eeve  nel ne (ee ge  Hvng e  oweve we o neve em o goove ee moo en n ny o o ogm ey e nonnconl exce o legng  weg   m!

he ypica bac extenso devices i mpose geneay ce the musce oading o the brddog sce boh rght ad e sdes o the umbar ad the thoracc extesors are actvaedhese may be ecessary or some types o perormance taig bu they ae -advsed o mos patens. Figure 43

o e oe o  don cle o weg c e no onee mcne nce ey o no ole jon moon nd  ence o oe oy moon en One cl ex ece  ennce e bly o blze e ne  e ce llown 

262

Low Back Disoders

For bac patents who have coprosed hp fexon owerng he weght soees causes he pevs o roate away fro  he ba ck rest Ths aso can occur f the wegh s owered too far hs produces hernatng condtons for the dsc! Figure 1

For paents who ust use he eg press exercse, we suggest they use just one eg at a te to ensure ha he pevs reans n contac wh he back pad and that they preserve a neutra spne (ote ha we stl consder hs a nonfunctona oor/oton pattern Fgue 5

Fgure 6 Two varatons ( and b of the cabe pudown exercse shoud be perfored wth the handebar owered o he chest rather than to the bac Ths enhances he roe of severa spne exensors and n partcuar he atssus dors for ubar stabzaton

xs, whn the handlba  ought down to th hest ath thn the b hh s tadtonal thnqu hlens the ltss oi n othe stzes s g 6 ab. As e wll see n a bsqent seton ths ys o ess o  t o a ponesed pogam

Advand Exriss

63

Safely Progressing Back Exercises The ulup, e be, a bo ptue  hapte 3 n be ae  halen an yet il npoate the aey eatue ote te ep thee vne o o the b thee ee,  ll peet a atonal avne b eeie

Highest Level Onc th patnt has mastr th avanc curl-up scrb n chaptr  sh may b nstruct to try th follong:  rac th abomn (f ncssary, rv th nstructons on pags 0-  Curl up aganst th brac, but o not cur up any hghr than n othr forms of th xrcs.  Prfom p brathng hl n th "up culup poston an h mantanng bracng Rman n th up poston ong nough to ta a f p braths

Th evel o ulup  be hlle o the touhe NFL ebake

Highest Level Th s bg can b mor changng by ncorporatng th rol scb n chaptr  (pag  togthr th ynamcaly contractng an rlaxng th abomnal all hl sustanng poston

Highest evel Th brog s mor manng hn th patnt conscously strtchs th han out forar an th foot out bhnall th hl nsurng that spn moton (partcularly bnng) os not ta plac If prfomanc objctvs ar srabl an f th patnt has no xacbaton of symptoms, smal rst an an ghts may b allo

Whn sarchng for ays to obtan maxmum myolctrc actvty from th bac xtn sor muscls,  scovr that somtrc bac xtnsor xrcss o not rcrut th ful poo of motor unts Many mo moto unts fr th som xtnsor moton s a sut of ths scovy, ths bac xtnsor xrcs, hch bus strngth an nuranc an hlps to hyprtrophy th muscls, as vlop. Whl th athlt s lyng pron on a bnch th th torso support on a movabl stff pa, plac ght n on han.Th g of th pa s plac unr th m rbcag h cantlvr porton of th spn s sghtly flx an thn xtn, combn continued

264

Lo Back Disordrs

Advanced Exercises for Back Strength and Endurance cotiued

th som slht tst bac to nutra (a) Th obct s not to actuall tst but to focus actvaton on on s of th xtnsorsto us mntal mar (chaptr  to assst n actvatn th maxmum numbr of avaabl motor unts Th spn nvr xtns past nutral ftr a st pac th ht n th athlt's othr han an hav th atht r pat th xrcs Thn mov th pa onar (prhaps about th vl of th navl) so that a ratr porton of th torso s cantlvr (b). Hav th athlt rpat th sts. Mov th pa farthr on th athlt's bo (prhaps to about th plvs) lavn mor of th toso cantlvr an hav th athlt rpat th ntr procss (c)

nothr varaton of ths xrcs s to prform th xtnson moton ov a m ba hr th ft ar scur () an th bal s mov prorssv toar th plvs th ach st () (S Golnb an Tst 00 or th ls ar cantlvr (f ) an th bal mov prorssv toa th chst (). Wh som strnth athlts hav sccssfu l us ths xrcs to nhanc pfomanc,  ar stl quantfn th muscl actvaton an ont loas. Ful ata l b psnt on ths an othr"strnth" xrcss nm upcomn boo for athltc prfomanc

Advaned Exerses

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Occupational and Athletic Work Hardening ertn worer an athlete encounter eman that reure rann tht e wul nver reommen o atien unle they were aolutely neceary Anyne nern gng eyon the eerce decre revouly houl e fuly are  th increae r o ac njury tha thee eerce wll oe Thee eere ime t er or occuonal ahlete hou e rercte to that grou becaue hey reent  level of r tha  unaccetable for any ut thoe who are wilng to aume them or the e o thlet or wor erformance Once agan hng the aroriate challene nvolve a len  linial r an cene oo ltle loa wll not rouce the ranng aataon an too much wl brea ue on Len to he ody an gve aequate re

Low Back Exercises for High-Performance Workers or Athletes  ll e wrtin a boo n another year or o on eviencebae hiherrmne trnng for the bac Gven the emhai of th oo on orer th econ  bref n ntrouory n enerl we tae tranng of the athlete ih the ame te ue n our re on aroch only two more te are aded We en n tage by entn the eentil moon an goovng aroriate motonmotor attern    rete owar enung jont an whoeoy taiZn attern tae 3  t  vel mule enurane aoun hee attern tae 4 i rete to enhann trenth An nally tage 5  to etabh oer Unfortunately, too many eetnl th lete are rane, or gven a rehalitaon rorm aed on trength an oer wthout an aequte foundaon o talZing motionmotor atte They en u ith b roem an are referre o u n th eon e wll brey coner eercie that may e heul o ether rer wh maning jo or ahlete The reurement of the actvte re nt xve or thoe who have adequately reare y materng al of the eerce rev ouy cue n the te ecfcaly, thee invual houl have maere ne on warene an e ae to rouce low c taiZin atte but my nee more wor to ueuly move though he range of moon ecfic to ther ta n ton they may nee more trength and enduane

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Lo Back Disordrs

Qualying the Worker/Athlete Th liica dciio ivovd i tagig a workr/athlt through th rogrsio o chalg i a art that ca  aitd ith citiic data. Thoe who a lookig or a st rci howvr wil fail at cratig a succssfu ogram for a idividua Graly w ld th workr/athlt' currt xrci tatus ad history o ijury with ou ow kowldg of i tiu load that rsult from various activitis ad our koldg of ijury mchaim to qualiy a idividua or a scfic xrcis ogrsio. W th ut our ducatd gu to th tst ad moitor atit rogrss to ur th maitac of a oitiv o o imrovmt i ytoms ad fuctio

Lumbar Stability With Elevated Simultaneous Physiological Work Rates Whil om idividual a maitai i taility ovr all sorts o activitis icud ig tho that rquir th taiizig muculatu to ait with hysiological chal g uch a lvatd rathig oths caot (McGil haratt, ad Sgui, 1995). W hav otd a comromi i th aility to tailiz mor ot osiury McGill t a. i r) although  hav ao dtctd that comromis i vrgi acs. Itrtigy tal athlts td to  oorr i thi aility to cocotract th abdomals to ur uficit taility durig high work rat ad highly challgd brathig tha thir hortr coutat. hi rctio aar to  uortd by th mot rct vidc hoig that talr workr hav a gatr liklihood o havig rturd moto attr whil rathig havily ad holdig si loads McGill t a, i s) Coidr th warhou okr, firight or ootal layr ho ust ork at a high hyioogical rat that rult i d ad lvatd lug vtiatio. Th iabiity to maitai cotat cocotractio i th adomial wal (.. th muscls td to rlax duig d ihalatio) i a idicato o comromid si staility artilay wh havy xtal oad that dmad a ta i a rqurd. hs idi vidual mut dvlo tailizig motor attr that will trar to al activitis

Spine Stability

Brthing s Elevaed

On tranng xrcs  hav vlop s to hav th nva   an xrcs b at an ntnsty to lvat vntlaton an thn  mmatly smont an aopt th s-brg postr on th floor. In ths poston th stablzng msclat mst rman somtcally contact; othr s, th brg postrs ost Havy vntlaton salso rq hovractng to goov th moto pattrns that coornat aphragm contracton an oth thoracc mscls nvolv n cnt ng fncton. h cp an brog posts ar also s afr vgoros statonary bng to groov stabl pattnng n all of th spportng mscls In ths ay  stablsh spn stabzaton pattrns n orrs an athlts al

Torsional Capability om activiti that athlt or works mut rorm ruir twitg ad th cratio o utatial tosioal momts. Th diffec tw th mhaics ivolvd i tistig ad th gratio of torioal momts a discusd i chatr 5 h qustio is how ca w maximiz taiity ad miimiz th risk of ijury durig

Advancd Exrcss

267

tag o tr too? Bca, a poly otd at oq aot h twt a po approatly o t th copo o th p a a qal toq aot h o/to a t  w o ta o too gao tl th a  qt hahy

fo Tosional Capacit Th tchnqu  hav foun for proucng lo spn loas h challngng th tor sonal momnt gnrators s to ras a hanh ght hl supportng th uppr boy th th othr arm an abomnally bracng (s a an b) to rsst th torsonal torqu th an somtrcally contract an nutral spn ynamc challng tst ng s rsrv for th most robust of athlts W oul nvr rcommn tranng on th torsonal machns sch as thos hr th athlt s sat th th plvs blt on an th uppr boy tsts aganst rsstanc) unlss spcfc athltc prformancs r th tranng objctvan thn th nvual must b ma aar of th vat rs of pursng ths approach

o y l ad taal oto patt a podcd wth th ao a  (g, hgh pll, low pll, ad chopp ) whh prod hgh tooa hall a o th la cop load aocad wth th ooa oq chall  t dpl  a th too  a tal potr t wod alo  w to cod th tal cto th p pdla dac tw th cal oc ad th a p wh choog th tchq to cotol th tooal oq ad ltat p load

Antalgic Posture From Sitting At o y clc  otc a ah o ac tol at a t Th t a tg too lo tdyg Typcaly thy  o a log pll ad th wh hy tad thy ha h ypcal atac por, lag owad at th hp ad al o datly tad ph

68

Low Bak Disorders

Specal Suggeston fo Those Whose Back Is Wose Wth Sttng and Then Have Touble Standng For these patents I may suggest

 puttng on a bapa weghng about 5-0 g 22 Ib) an 2 gong for a wal over ough groun for an hou or two mazngly (to some many patents report that ths wos wonersThe typal forwar flexe antalg posture requres the ba extensors to be atve (whh mposes a sub stantal loa penalty on a flexe spne)The bapa ats as a ounterweght to exten the spne an brng the torso uprght The ba extensors are no longer neee to on trat eetvely emovng ther ontrbuton to spne loa Wearng the bapa re ue spne loang!

Low Back Exercises Only for Athletes ii tlti bti ui pii tii tius A td li, w, t y ptit  t it f i t tlt  tii xi ud t ipti tt t   will l ti w bs Ti itily iptt ti ust b pid i: Atlti xiss  t  i  lt i ptit I dditi, t y tlt u bdybuildig pii  uidi  Ts ut t b ultd by tit T flwig xis  vd f tlt ly

Training-Specic Athletic Maneuvers T iu tu til i  itd titig ti  sd f ts w wt t x t vY pi t u  Olyi ius twig  ust dd tt  t tlt wit w I v b ssitd iily d ot p t xi bus it xbt ti b yts Oti, t tsil t pbiliti  dlpd wit t pi i  utl ositi wit  ully bd t uultu, but wit  tsil t llg T utl siti i t t ut ptu t ittd t ltd si lds; it i l t i ptu tt i tfbl t t tiviti tt ui tsil ts wit t t is f pi d Sti d t pw ui ts su t d by ftbll ys sould  dsd  d pd  t pit i uuy liitd by t vY f t lg i fxi i flxi, t  l  i xts w Tus, y ti t p i t t pw ilspyd d u wit  bd b It is iti f ts tlt t iti pi tility d b ius f t d d ul i dui iu ip fx tii uid  itig t All t f xi  i uipt   dld f ef tii But y w pf pps    dutd wit ubtti sitifi udti t wt diui i  b u  tis Hw,  xti is t  Supeining by D Ml i, w  isi ub f tudis v  ytid  iwd  xl, D iff    f vidig t dpt  ti tt  uidd pdity by i, d istd dvts  d  wits wit tb ut Fu, ubttitd iils f util ty, pyiy, bii, d t st u s filitti  us t jutiy t p ut iSuperainng t  stt pw, p, d u du T p bti t xit witut t uti  tility, biity, d t dditil ii  v dutd i tis b Wil t i  uti tt t piil d xiss  xllt

Advand Exriss

69

f pfn     n pn ld.  k p i nt tlt  f t dnd t nt n n   g f inin t   pn dl f t ndn f t inf tnq.  i n  nd nd  d f t p f  k. Fnll n dnin k t " t n  pfd   bgn nn f  kt t p  nd ti  tl t ptn f  t f t tinn i n.  tin l ik t fin  in t  i f  d  tk t tin t fi

On tho grong n popularty s non as th star xrsshh ar sgn to proot stablty throughout a rang of oton  plus sgn (+) s ran on th floor Th patnt bgns th th ft on th ntr of th + an prfors varous prat ovnt pattrns ovng nto ah quarant What s prfor n on quarant s rpat n anothr quarant for oton/otor sytry Varous pars of postons ay b obn th ffrnt posturs an ay b on th or thout rsstan hh ay b prov by thr ubblls or han grps on abls  for xapl th pars a an ban  an  tar xrss ar a for groovng pattrns suh as a tnns srv It s rual that you phasz abonal oontraton an ltng lubar oton to th patnts safty zon

Training to Squat and Power Clean q nd p ln  d i f dpn p f t  n.  nttn f  ppt  Y pl N fi f f lin  t.  ft   i t d t n tlt nd  f   btnti pn  in t k  n din t p dn. A t ld n  "t' n    pn lnd    d V f pp n N A n pf  nd p ln l nd   l k f nj  Etn Epn  n t nd t  b nd t p f t k t dl n t nn f  nq. Bt i  intn   t pi pd n in   n/t n ln f tnl t i tptd n En Epn  pnd  dpn t f  lifn tik. On n t f i f i ngt ind nd i ddd  t . Gnl pn  nt

270

Low Back Disorders

lu sn wl sv ny f h sfty ssus u ths ns n th lty t tk th shuls n hs t s n th n f n. S hv foun ht n th wht  n lks  s th sn hght vs th utty f hs s  thts h thn ottv whtls. Ths wy  lt n olsh  s ft wthu th lg bk los ssot th th ntl ouh stu n o ull o th . n ths w s s s tnt nts  vs to "tn sl t b slo, n fs   fst. F ths nts n ths ss h tu wht knts f th ul w n n h ntn  th g uss, ts usls n ths nvv n th shul ul n  fun lswh. P hts wh  n ghs  gvn w lfng ss wth thns lk n s s gu 14.7, ) n u ogs. W ly n w lns th   st th s us.

Fu 

Medicne bal f  and b and toss c or powe.

Looking Forward Rhttn nvs  ntnun t  hnqus tht ns ntons of tos stlty n vus nns nvlvn su ot tnng n t gssv hlln. Mny us ntnu t k •

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t unstn h nutns  stly  vus nns  th ntoy t tu nsn th  wys t nhn th ontbuton t unsn wht gntus n ns f usl vn  qu to hv sunt stlty whl sn th jnts

Advanced Exercises

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21

to idntiy th bst thos to ucat faulty oto ontol systs to oth ahv sufcnt stalty and duc th sk of nappopat oto attns oung n th futu; an to dvlop oto atts fo otal pfoanc n athlts

olla ffots twn scintists an cncans contnu to dvlop th sntif foundaton to justiy btt low ak njuy pvntion an habilitation aoahs Muh ans to b on.

References

Goldnberg, , an Twist P (2002) Strengh ball ining Champagn 1L Human Knts Mcl, S.M., Sharat M.T and un ]P. 995) Loas on spnal ssus ung smultanus fng an vntlay challng. Eonomics 38: 772-792 Mc SM nr . Puss R. an Bown  (n prss) Moto prfoman haatsts f th low bak: Lns to han a hstO of low bac oubls Vra-aa F n, S. an M M 2000) Abomna sns un curlus n bth stabl an abl suacs Phycal Tp 80 (6 564-69

THIS PAGE INTENTIONALLY LEFT BLANK

Epilogue

N

ow you have anther pespecive t emloy in your efforts t vnt and ehabltate bad acks I hope tha rm no on, hen yu ead ha ad backs jus happen r hat they cannot e diagnsed o gude heapy or ha hey ae slely he uncn  sychologcal facos or he comensaon syste, you wil use and reect ha yu are readng the msings  ndvduals ho have reached the end of he expertse No tha anyone has al he anses Wh each expeiment hat we erfm we may oain sme new nsgh u generally e are conroned th any me quesions So, ih each expermen e ecome relavely more gnoran And afer hundeds f experments we are s gnoant tha we ae temped o hink ha we are no ne ualfed o make ecommendatons about he  ack o anyone! Consde the vewpont descred n hs text and end  h yur own clinical isdm and experences The vey es cncans, ith h  have had the leasue o okn, had wndeul cnca skls and nsighs ut ade use of a scentic foundaton To the cincians- sh he condence o connue ith hat yu know orks and he nspraton and eadeship to ry ne appraches hen hins ae oe ac To he studens of cincal dsciplines and those nvoved n the cnnuin evel opment of he scenic oundaionthere ae so many oe excing exerimens o pefrm on he ndefu fascinaion ha e share, he lo ack May we al eny he cntnung ouney

73

Appendix A Raw Cross-ec tiona Areas (mm) (tandard Deviation in Parentheses) Measured Directy From MRI cans Veera eve

Muses LS

L4

L3

L

Ll

 rectus abdomins

787(250)

750(207)

670(133)

72(239)

576(5)

 recus abdomnis

802(247)

746(81)

693(177)

748(240)

54(99)

 external oblque

95(199)

276(17)

158(222)

 exerna obique

992(278)

1335(213)

1351(282)

 inerna obque

903(83)

155(37)

055(73) 1027(342)

900(5)

424(30)

 rans. abdomins

19(22)

237(82)

356(0)

596(50)

 rans. abdomnis

175(57)

224(48)

376(15)

646(83)

 abdominal wal*

04(393)

2412(418)

3269(422)

305(463)

 abdomna wa*  ongssimus hor.

46(377)

2420(475)

3329(468) 747(62)

3111(556) 175(370)

 ongissmus tor.

782(29)

 ilocosas umb

368(341)

 ocosalis umb

 inenal oblique

T1

248(228)

095(222)

1089(25)

1180(184)

1258(347)

1104(18)

118(316)

921(339)

395(223)

150(98)

1158(247)

835(400)

 mufdus

447(271)

343(178)

290(96)

289(66)

 mufidus

472(269)

366(157)

324(95)

312(76)

 assimus dors

232(192)

429(202)

717(260)

04(264)

256(217)

372(16)

682(260)

960(310)

905(331)

2151(539)

283(458)

2854(547)

265(405)

2614(584)

 lassmus dors  erecor mass**

986(338)

2234(476)

2933(382)

2833(456)

2723(428)

2601(559)

 psoas

1606(98)

186(347)

594(369)

177(285)

513(329)

330(210)

 psoas

590(244)

1820(272)

1593(29)

211(298)

488(250)

462(90)

725(209)

701(22)

552(92)

392(249)

320(97)

 erecor mass**

 quadraus umb.

625(249)

746(67)

614(89)

404(220)

326(5)

360(276)

1459(270)

145(249)

332(294)

334(285)

24(66)

52912(9123)

5183(9845)

54286(8702)

55834(812)

5909(6899)

63287(953)

 quadratus umb. Dsc area Toa area

*Abdominal wal incudes extenal and ntenal oblique and transvese abdomns. ** Erector mass ncludes ongissmus thoais, loostals lmboum and mutfdus.

74

Verera eve Tll

TlO

T9

T8

T7

T6

TS

93849) 93821) 55234) 55 1 70) 33189)

35190)

3297)

32780)

35353)

35573)

25428)

38330)

45829)

158159)

74289)

187432)

247724)

0231)

239257)

47293)

158228 )

19789)

203422)

25972)

832282)

9020)

43304)

04920)

84215)

77789)

74370)

2041285)

722279)

47135)

129100)

8794)

77995)

757)

33124)

05125)

93312)

7989)

79704)

7480)

782)

592497272)

1057570)

73290)

57945254)

77823982)

402372)

93372233)

27

Raw atera Distances (mm) Between Musce Cen troids and Intervertebra Disc Centroid (tandard Devation in Parentheses)

A.2

Vertera level

Muscles LS 

ectus abdoms

L rectus

abdominis

L4

2

3

L1

32(5)

38(7)

43(7)

46(8)

37(8)

-33(6)

-36(7)

38(8)

43(7)

35(17)

R

extenal obique

125(13)

30(0)

40(5)

L 

extea obique intena obque

120(9) 109(1)

25(9) 16(8)

33(7) 23(9)

L

iternal oblique

-103(9)

12(8)

2()



tas abdomnis

99(1)

08(11)

22(9)

7(9)

L trans. abdomins

-10(1)

-10(9)

-07(7)

09(9)

T2

102(8)

113(12)

19(8)

23(9)

102(9)

-15(4)

-4(7)

-20(9)

 ongssimus tho

22(4)

32(2)

32(6)

30(2)

logissmus thor

34(4)



abdomina wa*

L abdomina

wal*

-19(5)

30(6)

37(2)

 liocostals

umb.

52(4)

58(4)

68(0)

65(7)

 iocostals

umb

-48(6)

-60(10)

-65(9)

-67(7)





mutifidus

1 (1)

3(4)

13(3)

0(3)



multiidus

-4(7)

-2(3)

(3)

(2)



atissimus dors

102(8)

108(8)

122(2)

129(0) 128(7)



atissmus dors

-04(5)

107(9)

7(1)



eecto mass**

22(6)

34(7)

40(4)

42(4)

44(5)

42(3)



erector mass**

-21(5)

-33(6)

38(5)

4(6)

41(7)

-40(4)

R

psoas

54(4)

50(3)

44(3)

39(2)

32(3)

32(3)

L

psoas

54(4)

-48(4)

-42(3)

38(3)

-31(3)

32(2)



quadratus umb

81(5)

75(6)

63(5)

46(6)

46(11)

L

quadatus lumb.

-78(12)

73(4)

64(5)

50(6)

47(5)

1(3)

-2(4)

-1(3)

-1(4)

0(3)

Tota area

0(2)

*Abdomnal wal incudes extenal and nerna oblqe and tansverse abdomnis. ** Eecor mass incudes longssims thoracs iocosas umborum, and mltfidus

276

Vetea eve T

T0

T9

T8

T7

T6

TS

29(1) 6(7) 6(4) 67(11) 8(2)

1(2)

2(2)

2(2)

-2(2)

5(10)

29(9)

40(9)

4(8)

45(7)

46(7)

15(7)

15(4)

29(10)

-137(9)

9(8)

-4(6)

-147(0)

-5(5)

-51(5)

34(4)

34(4)

2(4)

31(7)

0(4)

25(5)

27(2)

40()

6()

-5(4)

-(6)

-31(2)

29()

27(6)

()

0(2)

0(2)

2()

2()

()

2()



A.3 Raw Anterior/Posterior Distances (mm) Between Musce Centroids and Intervert ebra Disc Centroid (tandard Deviation in Parentheses) Verter eve

ses S

4

L3

 rectus abdois

86)

73(14)

793)

94)

098)

 rectus abdoiis

805)

73(14)

84)

924)

6)

350)

204)

282)

9)

28 )

 eera obue

L2

 eeal obiue  teral obiue

328) 42)

259)

367)

 itera obue

47)

262)

406)



 asabdois

550)

28)

22)

366)

 trasabdois

505)

304)

230)

44(5)

 abdoa wa

586)

3 2)

72)

305)

 abdoial wal

597)

323)

202)

3 )

 logissus tor

-66)

-627)

-607)

606)

 ogissius ho

-65)

-636)

607)

-59(8)

 iocosalis ub

-57(7)

-6(7)

-62(5)

-597)

 iocostas ub

57(7)

66)

-61(4)

-58(6)

 ultiidus

-55(7)

556)

52(6)

-51(3)

 ufdus

53(7)

-56(5)

-51(5)

503)

 atssius dors

-45(16)

-47(12)

-47(0)

-39(8)

 aissus dors

437)

460)

-46(7)

378)

 erector ass

646)

65)

65)

65)

595)

-56(5)

 erecor ass

-63(5)

-65)

-65)

-625)

604)

575)

 soas

89)

5)

-7(5)

-95)

- 6)

42)

 soas

98)

24)

-64)

82)

4)

)

 uadraus ub

36(9)

-37(6)

-376)

 uadraus ub

-35)

-34(6)

36(5)

2(9)

8)

9(8)

ota area

0)

Abdoma wal lde exeal ad era oble ad ravee abdom.  Ereor ma ide ogm orai, ilooal lmbom, ad mifd

78

3 6) 34(4)

328) 24(7)

Vtb v T11

T10

T9

T8

T7

T6

T5

-564) 524) 571) 562) -475)

-494)

-482)

-475)

-473)

-472)

327)

247)

-227)

89)

-176)

-123)

75)

289)

237)

197)

77)

-58)

-7)

93)

-544)

-544)

-524)

-523)

524)

-47(4)

-503)

524)

524)

54)

5 3)

-514)

465)

-503)

298)

309)

327)

367)

376)

3210)

345)

79

Photo Credits Steve Brooks: Fg 94 Start McG Fgs 3a; 22 a ad b; 23; 47; 49; 412; 413; 44, a ad b; 47; 42; 422; 424; 425; 426 a hrogh d; 432 a hrogh d; 437; 438; 52; 13 a ad b; 4; 55; 6 a ad b; 65, a ad b; 82; 83, a ad b; 86, a ad b; 87; 80, a ad b; 8; 83 a ad b; 84; 85, a through f; 87; 88; 89 a ad b; 820 a ad b; 824; 825, a ad  0 a hogh ; 112, a ad b; 113a; 114 a hgh d ho  ag 233; gurs 33a; 135; 4 a though d; hotos o ag 264; h o ag 265; g 147, a hrough  Wam Marras: gr 71

8

Glossa anisotropic- o a asotropc mara s dpdt o h rcio o th appd oa or amp adu o s srog  comprssio h i  sio antagonist us ha opposs h uco o aohr  trm of toqu  o u hat may  cssa o u a sta joi breaking strain a hch tssu as bucke- sp may prc sva mods o usta havio h oum may uck udr comprssv oas  sufcit sfss s ot pr i th rotaioa dgs of dom Th buck s aormay a roato a a si jo rsu  vry arg passv issu focs dermatom aa o sk suppid ith art v ir y i pia rv oot eigenvaue- m of h ssa matr hat, if ss ha zro, idicat th poia for possi usta havor eigenvec orDcrs th mod ad s of usa havior, a what dit "ao h staiiy o dvop eectromyography masum of h cromyogam, or tra vt associa h musc oaco etiooaysis ad scriptio o th caus of uy or disa faiure toerance Loa at hich a ssu ais ordosis cuvaur o th umar sp hr ua oosis i th aura curv o h sp, hypoordosis occus th a d uma sp, ad hyprodoss occus ith a td umar spi

Mom of foc occus h a orc s appd hrouh a dtac aout a as o cra roaoa fot moment ar h prpdcuar stac  th ais o rotatio a a orc, hch as a momt myoeectric-O or ratg o a cic sia oaid om cotrac mus myotomeEcic sa oaid om coacg musc neutra ordosis h uma spi s ihr d or td

OHNaioa situ o ccupaoa Safty a ah nocicepiosato o pa ith a ocicpto (paissg ora odds rati cas  odds o a v occurg Fu paaio va a amp is prov o pag 30. osteope-Boy spus hat go o h sss pos of a vrra uuay ica tv o a usta oi

8

8



papation-U h hnd o l or spnl moon or hology pars interarticuaris-P o h vrbr h onne h  rln r o h nr rh nd i h s o rr pathomechanics-Mhn od h phology oisson's effectA mrl porty o n ls sh n wh srn ond nly rod proporonl rn n h ll xis provocative/nctiona diagnosis- Dgno d n ks  exere yo provocative testingProvoking ss h ovmn o dr lod  l n psychophysicaV h r soed  yologl or l pe o n ndvdl

sychosociaThs vrs nn hvor nd nde psyholol ri h  ppon o onol ov  sk nd sol rs sh  ho ndivdl r vid y ohr spondyoisthesis-A  o h p h s n nror r dlemn o h sprior vrr lly L4 or L5). strainA hng n lngh nolizd o r lng dimensons io nd x psd s  rng subfaiure-A pld lod h  l hn e lod reqd o  e i plid on synergistA sle h ssss nor n h m nnl ive toerance-A od vl bov h nY os   od y rion, drion res nd so on transmissibe vector rnmisl proy o ny or vor  d o 

ving n  long e lin on hi  s drd A prpndlr ln n be drn om h ore vor o ny ody on o drmin h momen r, o he poenl o h or o   mon viscoeasticT prpy o bng oh ls nd vos  s e ok o lods viscosity - rion   non o veot  ys movs n h dron o moion or impndng moion yied strengtT lod  hh  s bgns o xrn dme.

Index : Te re ni y n aczed foong h p nmr; fgr y an iz A Aaas A   abdomina bs abou 194 fo ahs 191 bomchanca suds 9619 nca as 19596 'pscpon gudens 99-200 psychophysca sds 99 and rang-ofmoon rsrcon

19-9 suds of ha r a and bood prssur 19-199 for workrs 18 abdomna bacng 210- 21  , 212 

21, 24, 25 abdomna conraon mainainng

210 211, 21

abomina fasca    V abomina hoowng 2-211,

2f 21 abdomna muscs abou 6-1 acvang spcfc porons of  acvaon wih xon asks 10 xciss 2 abomna wa abou -1 coconrang indpndn of ung vnaon pas 220 as umbar orso sabzr 244 dung sing 04 accssY prcss 4 f 5 aivy noran an pan  Adams M.A. 55, 11, 114 224,

125, 19 adpos ssu pads 52 arobc xrs in xrcs rsrpion 21 ag and discogn roubs 224 an haion 55 and o back dsordrs 11-2

40 15 an spn rang of moon  an spn ssu oranc 118

Aarana H  218 man da Assoaon ak dsaby quanfaion gud ns 4 anaomy hangs a njry 8 Andrsson E.A. 4 ndrsson GB 111 ndassn S 142 anma mods 55, 5 annuar spran 56 annuus abou 554 unr omprssiv oad 5 fau mcansms 56 fssurs of 4 inury mchansms 116 inIY o 55 See also haon anagc posu from sng 26 aonuosis of xrna abdomna obiqu 69 of nna abdomna obqu 69 of ransvrs abdomns 69 arm swning whi waking 101-102 spdn RM 112 ahs See alo spos abdomna bs for 191 avodn n rang of sn moon 1-19 basba achs crouh and hr 18 ahin ndpndny of xron 91 comping dsp inurs 16 fooba ayrs 189 gofrs 89 hgh-prforman ow ak xrss 26-268 26820 oongd ng on bnh 190 uaiyng for advand xrss

266 rdung raon momn 9 spf of ranng rmns

191-192 rainn shory afr rsng from bd 190

ahc manuvrs rainng-spcfc

26-269 Au M  Axr  111-2 r  10, 12

 baka numrous suds on  bak bs 194 Se als abdomina bs bak xrcs safy prossng

26-264 bak xnsors sng 226 ranin 25255 bak mus srngh 21 bak pain and bd s 12 bak srnh advancd xrcss

26-265

bagag handrs abdomna b sudy 195 Badwn M.L. 16 "bankru xprs  basba cachrs couh an hrow 8 a  9 add rs 6 bd roing ovr n 1 bd rs and back pan 12 Bdnsk R 51 bndng avodng n ong 220 fun  mchancs of 6-  6 and ohr spn moon 12 nn G. 19-9 bn-kn sups 10, 05, 10f

245

rgmak  19 rngSornsn F. 6 16, 21,

21, 225 Bgos S 01 bomchana facors abdomna b rsarch     affc on ow back dsorrs 6

9

83

84

ndx

biomaial far on b al rl f -6 mpra f  flu  pyial faor 3  liag wi pyia ad pral far 3036 bird dg xri dvd  bgir'  mm mi a 3/ ig vl 63

argg u f pridially 7 al  gd rag  ig 33 a l g, afly  ra g 6 Capma  73 C, Paul 68 Ci, . 6 Clw ] ff f xra Tu Lad  umar Spi Sality"

diagi dfiii  urr prai 8 iadqa, a far i rga w ba  pa i 3 ad pai drpr 8 pya pily a i 6 pylgal  pyil far 33-3 prvaivfuial diag i 3

 irmdia imri ld durai 6 rmdil  bla, durig ruu lifg 7-7 bld prur, ad admial bl 8 body war 07 bdybildig pri ipl appl id  p  oig Cmpayba i dy 30 gd N. 3 6 78 8 6 brig pai 8 braig rai   braig i xri prrip  0 idpd ly f xri  d pi  bi liy 6 3-3 66 rlr  row, S 7 bul 0 uwalr ] 6 8 ur .F. 63 o, K 36 r, cv 88 lr D   rRJ 63

3 Ira-dmial Prur Maim" 7   M aial il iy f  I  Viv Lumbar Sp"   0     3 3  paliza f  Cirl , VM. 7 l al wdm 0 li ii a fir m  g w i  pai 3- a  gu id l i  " rmmda i 3 mpai 3-33 mpr i uri , a diffr lad ra / mpriv la d, a lw a  dirdr ri  far 0 ul a, rmmdai  83-8 00 r  a il iy 37 Cui, .]  Crp, P   6   Cr]   3 umu laiv rauma pa way   url- p a 6 aivai-im iri  07/ advad 8 gir' 67 ig l v l 63 irmdia 8 imr ld durai 6  lal urfa 60 pr frm xamp 6/ ru adm aivai 7 06 ua pa i 8

ragi fr udagd ow ba dirdr 3-3 uw ilgy dgi 6 wrr ab il iy imp irm d 3 Diy ]P  dialiy o f ra m  3 lga riria  ud  i wi fi 63 di  riai Se i diual pi ag  3 Dla P  3  Duw M.  Du l ]  D  ] 

C abl pulldw xri 6-6 dvri  p m diig pror  i g 78 Cady LD 63 Cllaga, .. 006-07  7 7 8

Cada  Pa i Siy 3 all b mpr 7 frau alig 7 ury maim 6 ruur 7 Carr D   aaml xri ! Cavag, ]M 8 8 ral  iiza io 

D Daigr, K 63 Davi , KG   dfrmal vrra 7 Dli  3 drmam - Dy  

E

igvalu 3 3 igvr lai rgy rag -3 MG-ad pimizai 7 mply Se worr mplyr See also wrr wrpla mivaig rail ai pa 07 prvi rgi 78-80 d-pa fraur ( 0  d pa abu 3 i maim 6 d rag f p mi 6 66 87-8 dra  al muuar dua advad xri 636  xri prripi 8 flxr dura  6 lwr r mul dra 0 rgy wll 3-0 pidmilgi ud au  ig ad lgu 30 Marra ad llag 3  Nrma ad llagu 3-3 ri far idifid frm 0  iig 7-7

ndx

85

r xr 269 ud f  m f d y fr 220 r ng  bl zg mu l 2-26 durg w rdy br  16, 1/ xn fr pr lngd x 01 brhng ndpdly f 19 xr bh 26 xr mm,  lw b

flx bdmn l mu  v 0/ v d  f l dg fr 1, 0-11 xnr mul bly g 22 hp flxn , 20-2, 2 nbly h 229, 2 2 lw b ld durg x xr 10-106 f l um br p  19, 2

dv rgh d xr fr b d dur 26-26 dv d d brdg 22 bgn' bddg 2 bgr ur-up 262 bgr' d brdg 2 bl pul dw 26262 ml xr 26/ ly-mg xr  1, , 190 fr xnr mul 66,  09/ hgg xr 0 hgh lvl brddg 26 hgh vl url-up 26 hgh vl d brdg 26 rmd brddg 2 rmd url-up 2

drdr r fr 10 xnr mu bu 6-6 xr 6-6,  09/ fx by g 22 durng lg 99 lw  ld durng xr 06-108 mylr  l   22, 229/ xl blu bu  0- v lvl wh x d m n xr 109 1 0 v   lv w  h vru x 9-9 v  pr fl durg wlg 10 llurd 69 

9durng 9 mm durg pv u fr 9 9t rpd p x  2 r x  6, 91-92 flx l x ph m , 92, 96 xr dur  226 flg rv r 22-2 fbl ply lng hu / rg pf hl  muvr 26 rdy WE   WT mdl r m 1 ,   Fr, JW 62 frn hr  6/ rzr, M  1

rmd d rmd d brdg brdg 21 vr 22 mr xr fr  2 mr hld dur 26 lg  2 l w b xr prrp n u 216220, 2920 lw b hgh-prfrm x 2626, 26-20 lw b ld durng xnr xr 06-0 lw b ld dug flx x 10-106 mu v lvl wh vru xr 99 9/ mu ul r  r prm 10

mm gr durng p l dg fr u  lf t mmn pnl  vru pur 90t pv u fr d mm durg ful lx 9 pv u fr dung full flx 21 xrn blzr 11

yhr D  P  G Glbrh, Jh h  G rdrMr, M  11,  gdr lg gud 12 nd l w b d  dr 0, 0 d pr  vrbr  d p  u lrn 11 g fr 9 gh,  lw b drdr r fr 0 glbl blzr 1-1 Gldbrg r 26 glfr lumbr  ly f wg

rdr, w h  219 pu r 20/ prrp b 2-26 prgr wh fy 26-26 rmdl brddg 2 rmdl d brdg 29-20 fly rng hlg 2926 u d pwr l 269-20 blz xr 1, 1, 21, 2 6, 26- 2

f wlng 21 fml, pr vbr  Frgu,  9 fbrodp md  ,  f mg 1, 8 f m r n ym 0 ud n  wh njuy dbly 16 xbly, n xr prrpn 216-21

rr p, v lvl wh vru xr 99 rgm h, prpr u f rgm ud 162 rgm, mdl d  1 Eulr g 1-1 Ev  H 12 xr. S aso url-up up f bdml mu 2 dv nd brddg 2 dv d urlup 2

F f pul  f j bu    p  rg    fur lr 1 2 Fjrzjn  26-2 Frfn, H   11,  12 , 1 2

1 pn rg f m

1-9

glfr lf 6 Grvy,  9-0 12 Grn P , 19, 9 Grr,   2 Grv, D.W. 1 Grod E. 1 grvng blhg p 29 mn nd mr p 20-2 blZg mr p 21

Indx

87

duu ea 10 1111 elye e guideli e 1-19, 2 ad ydrau afer  1211  itae f teue 96 ad itaabdia reue 11 1 1 1- 1 2 a w ak dirder k fatr 150 lw ak lad durig 96, 99

teverteral di 54 lw ak durg exter exerie 10610 lw bak durig flexi exerie 104106 lw ak durig lftig 96 99 lw bak durig ttg 104 lw bak durig wakig 00 102 tial aut f eaty ie 9 elat f teitie

260, 26 Laible JP 115 lai 4 ayC 112 at 19 ateral ue tet 225 lateral bliue traiig 24-252

ad 1 lubdral faia 112 etu-trafe teiue 1-1 4 12 ISH guidelie 51-152 tiu e ad i ture 164-166 11 ad elv tit 164 redug lad 169, 1 0  1 review f  tly  jerkig 1-14 t  uat 11-119, 12 124, 164, 166 treuu ftig guidelie 11-12 twiig dig 12-1, 12 ligaet aut 5 faet aule 

durat ad ret eid 9, 15 utaed ad ad reutat ree  4 -aed futi ad ijury rik 9 9, 41 ad vertebal ariteture 4 51 lal tablize 44-145 eP. 162 lgiu aut 61-64 a luar tr tabizer 244 biue agle f lubar rti 6} i  wer lifte r 62 lgiiu ar ubou 62/ lgiiu tai

latiiu di abu 6 ativat leve wit exte da exerie 09t, 10t atvati rfie durig wakg 10} et geerati dug eak ladig fr uat li t et tetial i vau tue 90t aive tiue fre ad et duig ful ex 9t aive tiue fre durg full lx 122t eaB 150 legal area 4-5 leg e ak 261 262 leg raie a iarrate exerie 244 ei P 21 evatr taru rev 6 levatr taru lg 6 lifetyle f atet 224 lifter S wer ifter liftig  advie 10

ijuy ea 11 ijuy ater 9 ieiu gaet 6- i etra vere liga et  lgitudal gaet 5 ra eai ad ijy eai -9 aive tue fe ad et dug ful flex 9-99t ave tiue fre durig full exi 122-12t ueriu ligaet 6- durig witg 12 iira , 9 liea alba 69 tS. 1  206 iu K 12 lyd CEF 21 ad trl 56-5, 169 f 1 1 adig aeet wit virtual ie 22 avdae iedately after exi  15, 10-1 1 a fut f urvature f ie 12-124 iuiet a lw ak dider k fatr 150

et tetal i variu ture 90 aive tiue fe ad et dug ful flexi 9t ave tiue fre durig full lex 122t giiu trai ar lubu 6 6 100 giiu tai ar trai 62f t lgitudal ligaet 5 rdS. 4  gele fiefigter tudy 6 tz  116 ui 242 lw ak exere eiti iue 216-220 ig-erfra e exeie 265-26 26-20 lad durig exter exeie 106-10 lad durig fexi exere 104-106 lad durig liftig 96, 99 lad durig ttig 04 ad duri g w ak ig 100-02

JrgeeK 10 21 juag 206-20 uker 4, 1111 12 Juuru K  115 K Kawk W 152 15 Kele  54 Keley  9 kiet lit 1-14 Kig I   Kier Y 92 Kirkaldy-Wl WH  kee arg bak wile tretig 240-241 kwledgeutig i aie 11 Kbeg 116 KragH 111 , 1 4 KrauF 196 Kraue  16 KrerM 10 KfP. 4 L lable urfae taiig wit

88

nx

low bck disrders bsence of orgnic bsis 33-35 ffect of bimechnicl fctors 3639 nd ge 11-12 , 40 15 0 compenstin isses 32-33 deficits 130-131 defined 29 dignsis srtgies 34-35 mpyers preventin gude lines 178180 epidemilgic studies 2932 ndustril lifting jb study 3 1 nd job tyes 3637 3 nd mechnicl ding 36-3 modultin risk f 117 personl fctors 40 psychsci fctors 30 risk fctrs 36-3 150 twisting nd risk of 128 workers preventin gidelines 63-178 low bck pin significnce of first-time inj dt 36 virl invlvement 2 lower rcts bdminis 70 245 lower tors mscle end rnce s low bck disrder ris fctor 150 c s D 11

67 lumbr lumbr extensrs flexin distingishing from hip flexn 20-210 s low bck disrder risk fctor 150 lmbr joint sher stbility tsing fr 230-232 lmbr ligments 7Q! lmbr mbility myths 240 lmbr mtin isolting 55/ tsting fr berrnt gross lmbr mti n 228230 3D motion prfiles with EMG pttes 229/ lumbr mtin mnitr 53 lumbr prbems disingishing from hip prblems 236 lumbr rectr spine ctivtin levels with extensor dominnt exercises 110 ctivtin prfles dring wlking 10�! lmbr regin spine rnge of motin 88 lmbr spine diverting force rnd 1669

flexing 119, 123 mechnics nd kinetics 92-108 rricetive trining 214 trining stbilizers f 244256 umr stbility with elevted simultneus physolgicl wrk rtes 266 umr trs stbilizers f 244 umr vertebr prts f 4Q! umbdrsl fsci bt 79-80 ntmy 80 cllgen fber rrngement 0/ illustred 8 nd liftin 12, 17 stress lines 0/ lm-elvic rhythm 91-92 lne upright torso psture during 240-241 Lt S 9-10, 36, 163 21, 240 Lu WW 48 M mchnes trining with 261-262 cintsh E. 80 mll strlling 102 mmillry prcess 4Qf 51 mnilin 35 Mnnin AF 218 rklf K 54 rrs W. imechnicl Assessment f Lifting ynmics" 191, 198 imechncl Risk Fctrs"

31 32 153 Chnges in Trnk Dynmics" 57 ffectiveness f Cmmonly Used Lfting Assessment ethds" 152 emle nd Mle Trunk Gemety" 59 Inence f sychscil Stress" 35 Literture Revie f L ck isrder" 9 Rle f ynmic Three imensinl Trnk Mtin" 30, 37 153 Mrrs mdel risk ssessment 156157 Mrtin . W. 217 McCy MA 99 McGill  Anteri r her  f Sin Mtin egments" 1 16, 1 9 Asymetries in Trs ndr nce" 227 imechnics f Lw ck Iny" 117

Chnges in pine Height" 27 Chosing the Best Abdmin xercses" 10 Correcting runk Muscle Geomery 11 Creep spons of he Lmbr pin 1 4, 7 1 ynmiclly nd Sicly Determined Lw Bck Moments" 21, 22, 17 3 Effect f Abdominl Belt n rnk Muscle Actvty 97 1 4 WABA model 54 Inteertebrl Disc Heiion 127 75 Itr-bdominl ressure echnism" 15  [s-elocity I nvestgt in  Lengthening Behvior of rector pin Mscles" 2 Lod s o n pinl issues" 40, 26 o Bck Joint oding" 14 w ck Threeimensionl Jont orces" 2 Mesred nd Modeled ttic nd Dynmic Axi Trnk orson 72 Mesrement f Trnk Muscultre 59 Mechnic bilty f the In21 40, ivo Lmbr pin" 1  5 39 143 14 4 Mechncl roperties nd ilu echnics of Sine" 16  19 Myoelectriclly Bsed ynmc -D Mdl" 21, 22 ssive tiffness  Lmbr Trso" 97-J98 oteni f Lmbdrsl Fsci Forces" 0 Qntittive Intrmusc ulr Myelectr Activity" 74 Ressessmen f Rle f Intr Abdminl resse in pinl Comprssion" 19 Reltionship between umbr pine od nd Mscle Activity" 0607 Re of ror Loding HistY 124 Trnsfer of Lods between Lmbr isses" 92 McGill modes risk ssessment 156157 vil spine 2022 cenie A 14

n

ci pture tt 25 chcl ldg cig ilu e tlrc    jury prc 2-5  lw ck drdr 6 ici l 270 l igY  th 92 p  21 idigh t 209 ili wrkr di t

ucl ce 5 ucle di uc 671 u 5 cig yergt d ti  cti leel wih xtr it exercie 19 0t cii eel wih u xerci 9-9

89

teg 225-22 tt cr irpti 227  uculr r h 9-, 20 uculr uci ch  ijury  uculr trgh  uculr edc 910 20 yelctric uicc 6 yte 22-225 N ch A 5  ch A      97 til Itiut r Occup til ey  lh (NIO) cti i r cp

95 uy pei iiu ergy 19 J ichl  95 i 27  r  ucl 559   27  cii iig edig 22 xrci 1 , 177   190 ri lur flx r J6 rr   5, 11 ti ppi 9, 22, 2  cl r per 15-6 ch tr ijury 129- r d pick up pcil J15

citi uceecry  tilityr 1 citi rle du wlki 0 c-ecti re crctd r iu lie  cti 9t gru 60-6 lgth i uriht tdig ti d r u extre tu 65-66t t geeri durig pk li r u lit 00 t til i riu pte 90 9V ucl ect ig wih pe et 9 i tiu rc 

0, 10 lig uli 5-52 rik e pprch J 52 Wrkplc U  13ck Blt 9 eck itric xrci r 27 ere t l 22-2 Neuur  6 url ch u 5  rcte  5 ijury chi 16

2  hip    j cr tility 2 prud pte  lw ck dr rik ctr 150 u rc  rrr 126 yt it 0 uliiu u 6J-6 ci l wih  i rci J JOI ci pri urig wlkig 10 ch lwi iY 0 illutr 6 6  lur r tili 2 t gerti urig pk lig r ut t 1  ptil i riu pu 90 pi iu rc   duri ull xi 9 pi iu fc duri ull i 22  p bility 1 ucl citi ptt 2 ucl ctct wr  272

e duri ull xi 97-9t pie tiu rc durg ul flexi 2-2 p 72-7 udrtu luru 7-75 i 5-59 p ity r    rucure chge ter ijury 0 ury 75 rer c 5 ucle  2  6 ucl tr 26 uculr cctrci d lig  pti  0  tuk ucle 7, 19 d twitig 7 ucur edu c  bck heth 27 uild 2 i exerce recripti 2 like wth w ck dird 0 rtie d 227 d reduced rik  utur ck tule 

eutrl lrdi 75 eutrl pi pii  pi eurl piti  ic  0 21 cicpti pi  ciic ck pi 2 -pi -g ppch 192 Nr .W. ri  k  uui hyicl Wrk Expur ik cr    2 2 2 yiclly d ticlly tri w Bck t 21 22 7 c  Adil 13t  rk ucl Aciity 199   WABAK  5 ur  ruk uculu 9 til  Lurl c rc 0 ee  l   Adi rur i il pr i 97 Nye   79 ucleu ut 5 i Y ch i 1 1 6

9

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74

 occupation, of ptiet 224 odds tio eed 30 Ogov S. 127 ohope ic momens 54155 osteoporotic vertbrae 4 Ozkty A 81-82 p Pciia corpus cles 7, 80 pain ad ctivty ntolernce  boring in 82 liicly reevnt aspecs -82 cost of tretment 34 cutaeous pi 2 descriptors and diagnoss reli bility 82 ow back pi 36 12 modultion of percetio 35 nurobiology 12 nocictive pi 34 patiet escriptio of peceived excerbtors 224 paien descriptio of type d ocation 224 physioogicl  psychosocil fctors 33-35  scroiliac regio 2627 nd tissue amage pthoge esis 2 tissuespecifc types 2 Pajab MM 115 43 pas inteticulris 5  pas umborum bout 6  momen poteti i vrious postures 0 passive tissue forces d momets during ull flexio

7 passive tissue foces duing ful exion 121 pars horacis 6  patint g ad geerl condition 224 frst meetg with cliicia 223-

225 to chge 207 motivtion rhabitato progressio 20724 Pal A 21 Pat N 5 pedile 46/ pelvc tilt when xecising 216, 23240 when Iting 64

pecils pickig up 12412 ersol fctors eined 2 Ikge ith biomechaical n psychosocial ctos 3036 lo c isorde Ikage 40 rsk ssessment of 150 peture motor cotrol ttes s lo bck disorer risk fctor 10 hyscl thery 3 hysologic crosssectoal re o muscle 58 g spne moel 55, 7 Poisson's effect 112 Pongpasuegsa  152 153 Pote R , 3 postio waeess 214 ostio coro 56-57 osteior boy elemets iuY mechnisms 51 osteror super ior  lic spi e egion 26 ostue ntlgic ostue rom stt ing 267 fo exercse 20! h p postures 164166 11, 208' ! McKeze posure test 23 stg 37, 104, 17,  76/ sttc ork postues 37 stoo postue pologe 14 uright torso postue during unge 240-24 uight toso postu in sretching 24 oetil eergy s unctio of heigh 13-140 s uctio of stess and elstc eergy stoage 411 43

oe liters uckled sine  2! hyertrhy of ilocostas  logissius muscles 62/ ocke umbr spine 16 umr spine luoroscopy 12 umr verebre motion qutifictio 124 power liftg 270 ressheels st-ups 245 preventio iequcies in 12 i L1Y reve tion primer 18013 of lo bck disorers or eployers 1710 of o bck disoders for orkes 63-7 rehbiitio integrated wth

206

workplce loss preveton stuies 16263 rogressive isc injury 54-6 propriocptio 24 poectve clohig 78, 12 provocative/ucoa dagnoss 35 soas bout 72-74 functio 74 illusttio o 7! line o ctio 25-216 momet gnerto during peak loading for suat lift 100 momet pottil i vrious posurs 0 passiv tissue forces ad momes durig full fexio

 pssive issue foces dug full exio 12 psoas ctivto uring abomia exercises 245 ith lexio tsks  0/ relatioship with low bck demads 244 psoas majo ! psos stretch 24! psychoogc acos vews o 7- psychophysica pproach 3,

5253 psychosocia ctors Bigos sdy 30 d caustio of ow back disorders 30 importance of 41 infuc o biomechaica actors 1 kg with biomechc d personl facors 306 om sudy 332 separatio rom biomechcl factors 35 viws on 5 pulling as low back dsorer risk factor

50 reviw of 37 Puett  3 37 pushig s low bc disod risk co

]50

view of 37 pushing force vector

6616

Q quds lumoum bout 7475 illustratd 6; 7!   mbr tr biiz

244

Indx

momen generation dring pek loadng or st it lOOt moment potental in varios postres 0 pssive tisse orces nd moments dring ll lexion  passive tsse orces dng ll lexion 122t taining 24-252 R Rainville J 33 rang o motion. S alssine range o motion determining stbity or trainng 234-235 restoration s pmry goa 12 pd ballisic loding as lo back disorde risk aco 150 ra materil hndling 17 rection moments compting ith virtal spine

20-2 prtitioning 2  edcing 6616, 1 cs lominis abot 6-6 ctvation levels ith extenso dominant exercise s 10 110 ctivion levels ith varios exrcises 34 ctivation proies dring akng 103/ dring crnches 7 moment genetion dring peak loading or st t 100 moment potentil in varios postres 0 passive isse orces and momnts dring l lexion 7 passive tisse orces drng ll eon 121 rining 245248 pper and loer 70, 245 rects emos ctivaton leves ih varios exercises 3-4 rcts sheath 6/ ddell CR 1, 15 ehabiliaion bes apprach 205-207 exercise regimen gdelines 25-221 ideniyng obecives 223 iladvised recommendatons 1

motor contro reedcaton 130 positive sope in rogress 20 207 preventon integrated with 206 progressive treatments 35 nge o motion restoraton as primry gol 1 2 slo continos imprvemen 206 stdies 162163 tme ames 11-12 rehbiition patient progession aareness o spine osiion and msce contracion 20724 ensring stblizing moor pttes and mscle acivaion ptterns 214 stablizaton execises 214 Reilly T 113 Reitn M. 172 repeated sne lexion 2 repetiive sblre loads 134 eserch  alsoeidemologcal stdes bdominal bel iomechncl sdies 16-1 bdominal bel clinica rils 15-16 bdominal belt sychophysic

1 essre and stdies hear rate blood abdominl belts 1-1 sitting sdies 174-175 spine moion nt estng methodoogica conces 6-7 oklace oss revention sdies 162-163 resistnce rining machines 261262 rest beks 175, 17 17  2 Reyn  R 17 Richardson C 71, 12, 210-211 ring aohyss 4q risk assessment bot 14 bioogical signaldrven modes 16-15 MGassised otimzation 17 4D WATAK model 153-1, 1 6/ ow ack dsorders 363, 10 mba moton montor 153 NOS roach 15012 simple us complex models 17-1 Snook sychophysicl p proch 152153

9

Rissnen PM 7 Romn chir 261 Ros s JK 8 Rossgno M. 12 rotatres abot 60-61 manal therapy and ncton o 6 rot tares horcis 6 Roy SH 130 Rin corpscles 78, 0  scroiic pn  26 27 Schaer M 47 Schmorl's node 4 5 5, 16 Schtz . , 17 Schwartz RK 5 Schwarzer C. 34 sctica 242-243 seated vibion 37 sedenary ork 55, 11 Segin P 7- Shapiro A.P 33 Sharma M 7 Shpeys ibers 54 Shrratt MT  sher orce as o bck disorder rsk act

50 redcting 54 j   sheaing ly xed spn 2 sher inries 52 123 shear loading s ncton o spin cre 165 ShirziAdl A 172 shockabsorbing mechanisms 47 shoveling snow 6 Sddll, P 12 side bidg e dvanced 252 beginners 25 highest level 263 intermediae 25 intermediae vaition 252 isometrc hold dration 256 remedia 24250 Sihvonen, T 3, 130 sily stretches 2  7/ Simons A.PD 43 singletherapy pproach 6, 01 sitting antlgic posre rom 267 back worse when prescrition or 26 dmging conditions o 3 nd hernition 55 o bck loads dring 4 poste 37,  4, 17 , 76/

9

ndx

itting n) polonged benh itting fo thlete 19190 polonged iting eet 224 polonged itting ttege 7-176, 12 lohing 104 itting mp tet 26 it-p nd bk helth 1 0 bentknee it-p 10, 10 10< 24

pinenetl poition ing 240 ding bk exteno ining 2 n leg-e exeie 26! eheng 20/ emembeing 209210 n qt nd powe len 269270 ding tehng 24 withtndng elevted pne od 26

dentifyng poo tbilie 14-146 myth, ft, nd linl implition 4146 qlttive nlogy  qnittive fondon 19-14 ffiien 14 tlity ndex 26 tblition exee bot 14 begnne 26-257 bilding ml end ne 214

inn peiption of 29  inppopite exee 244 pehee it- 24 eommendtion gint 10, 177 pne omeion 104 lohed ittng 104 low  tbe le 4, 49/ low wlking 102 Smt  12 nook .H 11 12-1, 6 77  197 220 Snook pyhophyil ppo t wok limi 121 now hoveling 169 oft ie ttment 2 Soomonow,  7 , 77 png the k 240-241 , 242/ pinl mem 4-1 pin

pine otion, wene of 207-214 ine ote 164-66, 11 20 209/ ne oioetion 214 ne nge o f moi on nd ge 7 foowing iny 7- nd golfe 1-19 egltive lnde 4 nkge with low k diode 40 m egon t etoion  ehlition go 2 etiton wth dominl belt 97-19 thoi egion t ine tbilty.   tbiz

kng 40 exibiliy tnng 216217 ligmen t dmge  nitito of degeneive hnge 79 optiml loding mont -9 peeng nd tbilng 12 ping dng exee 24024 , 242 nmibe veto 16616 11 pine fntion in-vit l 20 in-vivo b 20-26 mthodology of nlyi 1 9 pine mehni biomehni of dn pne hnge 11 inem popetie of thoo lm pine 7-9 kineti nd noml lmb pine mhni 92-0 pinl memoy 114- wm-p effet on 90 pne moiity,  low bk diode ik fto 10 pine moion nit teting nml model 7 otion ontol u lod ontol 56

tion exeie nd bethng 14-146, 2224, 266 onfed wih whole body bne 140, 4 lmb oo blie 244 nd mltfid 144 nd mle oontton 11 mle' ole in  , 144, 1 4/ nd o 727 nd qdt mom 7 qnftion of 14 nd tnvee bdomin 71 144 pne tk ehnqe 209 , 2 10/ pne tiffne 142/ pino oe 4! pondylti  fe 116 pondylolithei 1 , 2,  o   thlete eding ik in 17192 wok denng 26-270 pine 26 qt u toop in lting 111 19, 1 212 4, 164, 166 qt nd owe en 269-270 tbiity   ine tily o 17

gooving tbiing moto pten 214 mle tning 244256 emnology 17 tnk bilton 216 nding-o -fl-fexon mneve 92, 96 97-99  exee 269 ti wok pote 7 tfne.  oint tiffne; pin tfne toke A. 115 toop   in lifing 11 119, 12-124, 164, 166 toop ot poonged 14 tength k mle tength 217  tength dvned exeie 26-26 n exee peipton 21721 ml tengt h  ml endne 9-0 240 oo mle tength 217 nk engh 217 teno i ftng gidei ne 17-172 eo ongoing 6, 7 ehing ping pine 24 die  epidemoogl tdie eeh bfile tivity, polonged 9 Seymnogl m 16 ny, W. 155 eio i fet 46  peo fet   pepino lgment 76-77 tno, C 21 ymon d T.L 6 ymptom ptent deipton of 224 T ylo  17 eell,  ,  5 Teh, . 0 1 2 tetng o ben g lmb motion 22-20

ndx

fo abant moto pattns duing challngd bathing 232-234 dmining suitabilit fo OM tainng and stthing 234235 tnso nduanc man nduan tims and atios 2271 tnso nduanc man nduanc tims of nomal woks VS. tos ith bak disods 228t fo lumba joint sha stabili 230-232 motion papation 23 232 muscl nduanc 22-228 povocativ tsts 225 Thom pson  N 7 thoaci ct spina activation lvls with tnso dominant iss 09, 01 activation pofils dung walkng 03/ thoaci gion spin ang of otion 8 thoacouba fascia 79. S also lumbodosal fasia thoacouba spin kinmatic poptis 87-89 ilotson M 36 tim of da as lo back disod sk fato 0 tissubasd isk assssmnt studis 50 tissu damag chang initiatd b 4 scaing dttio n 4  initiato of casa d o f hang 29 ducing 7 tissu daag pathognsis 29 tissu failu mthodolog of anasis 9 tissu load dtion 2/ tissu vscolastiit 74 tou contl 56-57 tosional capabilit 267268

miofatuin 48 ostopooti minal loss 48 slo ush 48 49/ taining hath vs. pfomanc 206 safl nasing hallngs 29264 taninsii athlt manu vs 268-269 tansmissil cto 66-68 8 tansvsais fasia 69/ tansvs adominis aout 707 atiatio n lls with vaious iss 93-94 ilustatd 6 8 mpaid uitmnt folong inju 20-2 and sn stailit 7 44 tainin 248-22 tansvs ss 46 5 73/ tansvs tabcua damag to 48/ tatmnt inadquas in 82 Toup J. G 3 73 74 tunk flbilit 26 tunk stabiiz ation 26 tnk stngth 27 twstn about 28 fqunt 37 and liamnts 72 whl lifting 72 -73  82 twistin toqu 72 82 Twom 1. 6 78 7 Tnll A 3

tosional as low 50 bak displacmnt disod isk facto tosional machins 267 toso flion 63 9-9 2 toso motion as low back disod sk facto 50 toso muscl stngth 27 tabcula aangmnt of 46/ bucklng stsss 4/

an uld MW 77  206 vta aout 4 ahittu and load baing 47- inj mhan isms 6 postio lmnts 5-52 3 undstanding mhanis 47 vbal od 4/ vtal foamn 4/

U no K 72 unknown tiolog dagnosi 6 pp ctus abdominis 70 245 upiht toso postu duing ung 24024 in stthn 24 V Valknu HA. -2 Valsalva manuv  97 29 Vanhaanta H 34 Van Poppl MM 95

93

al ostophts   i al tabula buckling stsss 4�/ vation 37 50 Vdman  9  39   74 igilan buzzs 79 vial inction 28 vitual spin aout 2022 dvlopmn of 23 2 ampls of modling poss 2 26/ flowha of modling pocss 24/

and  WATA mod 54 subct montoing mthods 22/ sujt simulatng tossing of objct 2 / isual modl 22/ isous fction duing 29 W Waddll G 33 waking am swng and lumba spin loads 0 fast walkng 28 low ack loads dung 0002 lumba motion duing th spds o  / slo walking 02 spd and lba spin loads 0 Walsh NE 9 ahous woks abdominal lt stud 95 amups ffct on spin chancs ] 90 and visous fiction 29 Wassll . 96 W H.  2 ight lifts. S pow lifts Wls  4 Wnk M 33 Wstgaad H 62 Wild G 55 Winkl  62 Woodb   A. 72 oks aoiding nd ang of spin

motion 6466 ompnsation isss 3233 tion aft polongd ion 70-7 highpfoman low bak ciss 265-26 intaabdominal pss and liting 7-72 involving in gonomic pcss 80

94

Indx

wrr (cont) ltng thy  rn 73]7 lying fr dvnd re 66 ng rtn en 66 69 rt br 75 77 7  8 td wr 776 l-prvd tr 3   nt pt 787 8 twtng whl ftng 7-73 8

rpe  also epy degnng vrle r 80 njry prventin pr 8083  degn 3 6 80 ldng t gdelne 8 l prevntn tde 6-63 lw  direr nd jb tp 36-37 3 tnl wr hrenng 6570 ptl r tr 50 prevntn f   drdr 78-80

pyhphyl pprh t lit 553 raw mater ial handling

1 78

repttin  lr veen 39

lp nd fll 50 vgn br 79 Wrple e  B lt S 9 y

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About the Author Sa McGl, , s  pressr a he Unversy  Wr in

nri, Canaa n egnze eure an He r in sine unn annennay inuy pevnn an ehabn as en mre han 200 sien puins ha ass ua unn  k nuy meansms nvesgan  ssue  ng uing ehain prgrams, an e rmuan  wk eae njy vane sraeges e as reeve sevea wrs r hs k nun he Vlv Beninering Awa r w Bak Pan Researh m Seen. D MG hs een an nvie eue a many unvesies an eivee me an 200 inve aesses  siees aun he l. As a nsuan,  has pve eperse n assessmen an reun  he risk   ak n an rehaan eerse esn  vemen en ies pans pessina hees an eams an ea rms e s ne  he e senss wh nsus n  whm ens ae eulaly eere

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