Full Iliopsoas Muscle Description
[Continued from above] . . . Flexion of the hip by the iliopsoas is an essential part of many complex motions such as walking and running. The iliopsoas of both legs can also work together to flex the trunk at the hip when other muscles hold the legs steady, as in sitting up from a supine (lying-down) position. The iliopsoas muscles also have the ability to laterally rotate the thigh at the hip. This rotation results in the leg and foot moving so that the patella, or kneecap, points away from the opposite leg.
Prepared by Tim Taylor, Anatomy and Physiology Instructor