Origins, insertions, innervation and functions of the inner hip muscles. Iliacus is a triangular muscle of the iliac region which together with the psoas major, comprises the iliopsoas muscle.
The iliacus is a flat, triangular muscle which fills the iliac fossa. It forms the lateral portion of iliopsoas, providing flexion of the thigh and lower limb at the acetabulofemoral joint.
The iliacus muscle is shaped like a triangle, flat and an exact fit of the iliac fossa — the curved surface of the largest pelvic bone. Together with the psoas major muscle, it is also called the iliopsoas muscle. A portion of this muscle is attached to the iliac fossa, two-thirds from its top./GettyImages-615732108-b0654b67bb514e318ddd7a475a034979.jpg)
It’s made up of two muscles: the iliacus, the psoas major. These muscles work together to flex your hip, as well as stabilize your hip and lower back during activities like walking, running, and rising from a chair.