|Origin||Upper two-thirds of the iliac fossa|
|Insertion||Base of the lesser trochanter of femur|
|Artery||Medial femoral circumflex artery, iliac branch of iliolumbar artery|
|Actions||Flexes and |
|Anatomical terms of muscle|
The iliacus arises from the iliac fossa on the interior side of the hip bone, and also from the region of the anterior inferior iliac spine (AIIS). It joins the psoas major to form the Iliopsoas. It proceeds across the iliopubic eminence through the muscular lacuna to its insertion on the lesser trochanter of the femur. Its fibers are often inserted in front of those of the psoas major and extend distally over the lesser trochanter.
In open-chain exercises, as part of the iliopsoas, the iliacus is important for lifting (flexing) the femur forward (e.g. front scale). In closed-chain exercises, the iliopsoas bends the trunk forward and can lift the trunk from a lying posture (e.g. sit-ups, back scale) because the psoas major crosses several vertebral joints and the sacroiliac joint. From its origin in the lesser pelvis the iliacus acts exclusively on the hip joint.
Right hip bone. Internal surface. (Iliac fossa visible at upper left.)
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