The problem with sitting exists beyond the chair as well. Normal standing posture requires little muscular action to maintain an upright position. In the presence of a hip flexor contracture due to prolonged sitting, forces are placed anteriorly across the hip requiring the hip extensors to counteract the force. Increased muscular action and metabolic cost creates the desire to sit, perpetuating the circumstance which initiated the hip flexion contracture (Neumann 2010).
Quick facts regarding the hip joint:
-Normal hip flexion AROM: 120 degrees; extension AROM: 10-15 degrees
-Unmodified, ovoid ball and socket joint with 3 deg of freedom
-Capsular pattern (as defined by Cyriax): hip flexion > restricted hip ABDuction > restricted IR
-Closed packed position: Hip extension, ABDuction, IR
-Open packed position: 30 deg flexion, 30 deg abduction, 20 deg ER
Quick facts regarding the psoas muscle:
-The psoas attaches proximally along the transverse process of T12 and all lumbar vertebrae
-The muscle attaches distally on the less trochanter of the femur
-The iliopsoas is a stong hip flexor and tilts the pelvis anteriorly as well
-If the pelvis is not stabilized the psoas will pull the lumbar spine into excessive lordosis
Engage the Transversus abdominus (TrA) prior to moving from sitting to standing. The TrA provides a posterior pelvic tilt to counteract the force of the psoas muscle. Additionally a posterior tilt does not allow the lumbar paraspinals to contract as readily. With proper cueing, the gluteus maximus can then be engaged and stress will be taken off the low back.
Enjoy the video- Jim