Scientific Core Conditioning y
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Critical Point is abdominal mechanism is active during what is called the critical point, which is approximately 90% of maximum lumbar flexion (45degrees). At the critical point, there is a switch from muscular to ligamentous support (and vice versa when coming from flexion to extension).
Figure 10: Flexion relaxation response Ref.#45 – Basmajan, Muscles Alive
During this phase, abdominal support for the lumbar spine is of great importance. If the abdominals are weak or uncoordinated, there is a momentary loss of support for the lumbar spine. is greatly increases the risk of injury.
Flexion force + Extension force=Stabilization HYDRAULIC AMPLIFIER MECHANISM As the erector spinae musculature contract they expand. Because they are encased in a sheath of thoracolumbar fascia, their expansion creates intercompartmental pressure (ICP). is ICP creates “hoop tension” within the fascial sheath, with the net effect being a pressure or hydraulic erection force.
TVA & I0
TVA & I0
When the trunk is forward bent to near maximal ICP ICP lumbar flexion, the erector musculature are electrically silent. At this point there is tremendous elastic Fascia tension created in the erector musculature. is tenErectors Figure 11: Mechanism producing sion force is added to that of the stored elastic energy intercompartmental pressure of the posterior spinal ligaments, as well as the force created by the abdominals through the thoracolumbar fascia. Intra-abdominal pressure, thoracolumbar fascia gain and hydraulic erection all act as a force couple with the gluteus maximus and hamstrings to perform lifts from a forward bend position.
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