Leg Training Myths Exposed.
Squatting to parallel with legs bent at 90 degrees not only makes the exercise less effective, but increases the risk of injury. By not squatting through a full range of motion, you can't maintain proper lumbosacral body mechanics.
When performing the squat, the sacrum undergoes a process known as nutation
. It tilts forward relative to the two ilia on either side of it. At approximately 90 degrees of knee bend, the sacrum tilts back in a process known as counternutation
. These two functions, nutation and counternutation, basically describe the movement at the sacroiliac (SI) joint.
However, proper SI joint mechanics help to ensure optimal functioning of the rest of the spine. For example, some literature links SI dysfunction with lower back pain in up to 80% of cases.
In order to perform a full squat, flexibility and range of motion must be maintained in the lumbar spine and SI joint, as well as in muscles such as the iliopsoas, hip external rotators, piriformis, and gemelli.
If a client can't squat past 90 degrees of knee bend without their heels raising or their body bending excessively forward at the waist, but they can
squat all the way to the floor while holding onto something, we know there are muscle imbalances and stability issues around the pelvic/lumbosacral region as opposed to a knee or ankle dysfunction. Great for testing your squat depth and great for keeping out the land shark.
Additionally, improper pelvic, hip, and/or lumbosacral mechanics could manifest down the kinetic chain as recurring knee or ankle problems. Thus, regular performance of the full squat offers a "screen" of the athlete's pelvic and lumbosacral flexibility. This could prevent injury or muscle imbalances long before they become chronic.
Alwyn Cosgrove, http://www.tmuscle.com/fr...training_myths_exposed
post edited by SheRu - 2010/04/13 19:21:15