The |iliopsoas| is actually the blending of two muscles, the large, flat triangular iliacus and the fusiform psoas major. It is considered a single muscle group that begins deep in the back of the abdomen and converges towards its insertion on the back of the |femur| (upper leg bone). It is a powerful flexor of the hip joint. It flexes the thigh when kicking, or the |pelvis| and trunk when doing |sit-ups|.
