0 one of the two muscles on each side of the body that go from each side of the spine to the top of the thigh bone --
His psoas major muscle, which lifts the leg for the next stride, has four times the normal cross-sectional area.
The lateral cutaneous femoral nerve pierces psoas major on its lateral side and runs obliquely downward below the iliac fascia.
Here the tendon of the psoas major muscle passes over the medial chamber and the tendon of the iliacus muscle runs over the lateral chamber.
It emerges from the lateral border of the psoas major just inferior to the iliohypogastric, and passes obliquely across the quadratus lumborum and iliacus.
As with all quadrupeds, the tenderloin refers to the psoas major muscle along the central spine portion, ventral to the lumbar vertebrae.
Though the iliopsoas is sometimes considered a member of the anterior compartment muscles, the iliacus and the psoas portions do not share the same innervation.
Imbalances in muscle strength and length are also a cause, such as weak hamstrings, or tight hip flexors (psoas).
They proceed anterior and inferior along the medial border of the psoas major muscles.
