CLINICAL EVALUATION & TESTING
Darin A. Padua, PhD, ATC, Column Editor
Clinical Movement Analysis to Identify Muscle Imbalances and Guide Exercise Christopher J. Hirth, MS, ATC, ATC, PT, PT, PES • University o North Carolina, Chapel Hill
M
OVEMENT is an essential component o daily lie and athletic athleti c perormance. Human movement is inuenced by an individual’s individual ’s structural alignment, muscle exibility, muscle strength, and nervous system coordination o muscle responses to a changing environment. Observation o human movement can be used to develop strategies or prevention o injuries and enhancement o athletic perormance.1-3 The Overhead Squat Squa t Test Test can be used to qualitatively assess an individual’s overall movement patterns. The results o this test can then be related to goniometric measures (muscle exibility) and manual muscle testing (muscle strength) streng th) to develop a comprehensive view o the individual’s movement characteristics. 1 The inormation can provide the basis or therapeutic exercise recommendations or stretching o potentially overactive and tight muscles and or strengthening strengtheni ng o underactive and weak musculature. mu sculature. To To optimize unction, the individual should be progressed to an integrated unctional exercise program. 1 The purpose o this report is to explain how to set up and use the Overhead Squat Test with associated measures o muscle length and strength. Common movement patterns observed during perormance o the Overhead Squat Test will be explained, along with exercise recommendations or one compensation pattern.
Overhead Squat Test Setup The Overhead Squat Test involves a two-legged squat with the arms raised overhead (see Figure 1). The athlete is instructed to (a) stand with eet hip-width to
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shoulder-width apart, (b) toes pointing straight ahead, and (c) arms raised above the head. From this start position, the athlete is instructed to squat down as i sitting in a chair. The observation is made rom three views: anterior, lateral, and posterior (Figure 1). Ater perorming 5 squats or the anterior ant erior view, the athlete perorms 5 squats or the lateral view and 5 squats or the posterior view. The clinician notes the movement pattern characteristics by recording whether or not a particular characteristic was identifed during perormance o the test (Table 1). © 2007 Human Kinetics · ATT 12(4), pp. 10-14
10 July 2007
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Table 1. Movement Pattern Characteristics
View
Movement Pattern Item
Anterior
Toe Out Yes
Table 2. Potentially Overactive/ Tight Musculature and Underactive/Weak Muscles
No
Faulty Movement Pattern
Potential Overactive Muscles
Potential Underactive Muscles
Toe out
Soleus
Medial Gastrocnemius
Lateral Gastrocnemius
Medial Hamstrings
Biceps Femoris
Gluteus Medius
Tensor Fascia Latae
Gluteus Maximus
Knee Moves Inward (Valgus) Yes
Lateral
No
Arms Fall Forward Yes
No
Excessive Forward Trunk Lean Yes
Posterior
No
Flattening of Medial Longitudinal Arch Yes
No
Gracillis Popliteus Knee moves inward (Valgus)
Overhead Squat Observations Anterior View: Observations made rom the anterior view o the overhead squat are ocused at the eet and knees. A common compensation at the eet is the oot turning outwardly (toe-out; Figure 2). When observing or the presence o toe-out, the clinician should assess the position o the frst metatarsophalangeal (MTP) joint in relation to that o the medial malleolus. The 1st MTP joint will align with the medial malleolus in a normal oot, whereas the frst MTP joint will appear lateral to the medial malleolus with oot turn-out. Table 2 lists potentially overactive/tight muscles and
Excessive orward trunk lean
Arms all orward
Hip Adductors
Medial Gastrocnemius
Biceps Femoris (short head)
Medial Hamstrings
Tensor Fascia Latae
Gluteus Maximus
Lateral Gastrocnemius
Gluteus Maximus
Vastus Lateralis
Vasus Medialis
Soleus
Anterior Tibialis
Gastrocnemius
Posterior Tibialis
Hip Flexors
Erector Spinae
Latissimus Dorsi
Middle Trapezius
Pectoralis Major
Lower Trapezius
Pectoralis Minor
Rhomboids
Coracobrachialis
Posterior Deltoid Rotator Cu
Flattening o medial longitudinal arch
Normal
Foot Turns Out (Toe Out)
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Peroneus Longus
Posterior Tibialis
Peroneus Major
Lower Trapezius
Peroneus Tertius
Medial Gastocnemius
Lateral Gastrocnemius
Gluteus Medius
Biceps Femoris Tensor Fascia Latae
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underactive/weak muscles that have been associated with this compensation.1 Compensations at the knee involve inward or outward movement. Inward movement o the patella over the frst MTP joint (toward the midline o the body) during the squatting movement creates valgus stress at the knee (Figure 3). Table 2 lists potentially overactive/tight musculature and underactive/weak muscles that have been associated with this compensation.1 Lateral View: Observations made rom the lateral view include the lumbo-pelvic hip complex (LPHC) and upper body positions. Two common compensations are excessive orward leaning and arms alling orward. The trunk should remain parallel to the lower leg during the descent phase o the squat. I the two imaginary lines do not remain parallel, orward leaning is excessive (Figure 4). During perormance o the Overhead Squat Test, the arms should be held over the head in an elbow-extended position and parallel to the torso. I the arms move orward in relation to the torso, the observation is designated as “the arms alling orward” (Figure 5). Table 2 lists the potential tight/overactive and underactive/weak musculature associated with these movement compensations.1 Posterior View: Observations made rom the posterior view include the positions o the eet and the lumbo-pelvic hip complex. Normally, the calcaneus should stay parallel with the lower leg; however, a
Normal
Excessive Forward Trunk Lean
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Normal
Arms Fall Forward
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Normal
Foot Turns Out (Toe Out)
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common compensation seen at the eet is pronation. During the descent phase o the Overhead Squat Test, the clinician may observe attening o the medial longitudinal arch, along with eversion o the calcaneus in the rontal plane (Figure 6). Table 2 lists the potential tight/overactive and underactive/weak musculature associated with this movement compensation. 1
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the Overhead Squat Test can be trained in a single session to reliably perorm this assessment.
Exercise Recommendations
Normal
Foot Pronation
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Reliability of the Overhead Squat Test Intra-rater reliability o observations recorded during subject perormance o the double-leg overhead squat motion was assessed in a group o 20 subjects (11 emales, 9 males). Photographs were obtained by a digital camera rom anterior, posterior, and lateral views at the point o maximum knee exion. A certifed athletic trainer with no previous experience in scoring the Overhead Squat Test examined the digital photographs rom all views and determined i the ollowing movement pattern characteristics were present: (a) toe-out (anterior view); (b) inward knee movement (anterior view); (c) excessive orward trunk lean (lateral view); (d) arm all-orward (lateral view); (e) medial longitudinal arch attening (posterior view). Analyses were perormed on two occasions separated by 48 hours. Prior to analyzing the digital images, the rater underwent a standard instructional training program. Intra-rater reliability was assessed by calculating the Kappa coefcient between scores rom the two assessment sessions or each movement characteristic. The Kappa coefcient values ranged rom .85 to 1.0 or all movement patterns, except right toe-out (Kappa = .76) and let oot toe-out (Kappa = .75). The fndings suggest that the Overhead Squat Test is a reliable tool or identifcation o aulty movement patterns. Furthermore, individuals without previous experience scoring
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The inormation provided by the Overhead Squat Test, along with associated measures o muscle length and strength, can help the clinician to design an appropriate intervention program. A treatment approach that has been clinically eective involves stretching o overactive/tight muscles, strengthening o underactive/weak muscles, and utilization o exercises that incorporate unctional movement patterns. 1 For example, an individual who exhibits inward knee movement while perorming the overhead squat may have overactive/ tight hip adductors, with the gluteus medius underactive/weak. The clinician could utilize an inhibition technique or the hip adductor complex, such as rolling on a oam roller (Figure 7). Oten there are tender points in these muscles that are painul when pressure is applied. Placing constant pressure on the tender points or 30 seconds is thought to decrease muscle spindle activity in the overactive muscle. The next step would be to stretch the inhibited muscle (Figure 8). In this case, one could perorm a standing hip adductor stretch or 20-30 seconds. Once the overactive/tight muscle group is inhibited/lengthened, the ocus would be directed to activation o the weak gluteus medius. Hip abductor muscles may play a vital role in controlling knee valgus motion, especially in emale athletes.4 An isolated resistive movement pattern could be used to increase activity in the weak muscle (Figure 9). The last component o the intervention would involve activation o the gluteus medius in a unctional movement pattern, such as lateral tube walking (Figure 10). This treatment approach can be utilized to address the various compensation patterns identifed by the Overhead Squat Test.1
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In conclusion, the Overhead Squat Test can be a useul or identifcation o movement dysunction. This results o this test can be related to clinical measurements o muscle length and strength to develop a corrective exercise plan to improve movement patterns and possibly reduce the potential or musculoskeletal injury.
References 1. Clark M, C orn RJ, Lucett S. Corrective Exercise Specialist . Calabasas, CA: National Academy o Sports Medicine; 2005.
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2. Ford KR, Myer GD, Hewett TE. Valgus knee motikon dur ing landing in high school emale and male basketball players. Med Sci Sports Exerc. 2003;35(10):1745-1750. 3. Yu B, McClure SB, Onate JA, Gus kiewicz KM, Kirkendall DT, Garrett Jr. WE. Age and 7 gender eects on lower extremity kinematics o youth soccer players in a stop-jump task. Am J Sports Med. 2005;33(9):13561364. 4. Hewett TE, Myer GD, Ford K, R. Anterior cruciate lig ament injuries in emale athletes, 10 Part 1. Mechanisms and risk actors. Am J Sport Med. 2006;34:299-311. Chris Hirth
is a lecturer in the department o Exercise and Sport Science at the University o North Carolina–Chapel Hill. He also serves as a Sta Athletic Trainer and Physical Therapist at the James Taylor Campus Health Service.
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