In 1962, AA Michele dedicated 550 pages to the iliopsoas in an eponymous tome and summarized its importance in alignment as follows,
“Any and all defects of the spine and the hip joint structures should be evaluated in terms of disturbance of function of the iliopsoas.”
Living from couch to office chair is the lifestyle for most urbanites. Sitting in this position requires the hips to be flexed and the iliopsoas (psoas and illiacus) is one of the major muscles group responsible for holding this position. The psoas originates from the transverse process of the lumbar vertebrae and inserts on the lesser trochanter of the femur. The illiacus originates from the iliac, part of the pelvis and inserts at the same lesser trochanter. Being stuck in a hip flexion position for hours on end means that these muscles remain shortened even in standing position, and the shortened muscles pull the vertebrae and the pelvis down towards the femur, leading to hyper-extension of the spine or lordosis.
These tight muscles are also activated during sit ups when the feet remain grounded, so instead of strengthening the lower abdominals to counteract lordosis, transfer of the exertion from the abdominals to the iliopsoas only further exacerbates the hyper-extension.
To correct lordosis, the wide leg angled poses of trikonasana, virabhadrasana II and parsvakonasana stretch out the iliopsoas, while the lower abdominals can be activated to tilt the pelvis forward slightly.
For proper alignment in these asanas, the arms and shoulder girdle lift the ribcage up and off the pelvic bones. The thoracic spine is lengthened as the ribcage lifts up and the lumbar spine is lengthened as the tailbone is tucked in. Engaging the abdominals pulls the ribcage in and stack the thoracic vertebrae in line with the lumbar.
Breathing in full, deep breaths in this position also stretches the intercostal muscles and the abdominal muscles around the ribcage to prevent it from collapsing over the pelvis.
To prepare for or to complement the above asanas, poses like the setu bandhasana and the ashwa sanchalasana provide gentle stretches for the iliopsoas, and especially the rectus femoris, another important hip flexor and a major muscle in the quadriceps.
To isolate and strengthen the lower abs, elevate legs 90 degrees to the floor, cross at the ankles without squeezing the feet together, and lift the pelvis off the floor in small controlled movements.
