Iliacus - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The iliacus is a muscle of the posterior abdominal wall. It is a fan-shaped muscle that is situated inferiorly on the posterior abdominal wall. It combines with the psoas major muscle to form the iliopsoas – the major flexor of the thigh at the hip joint. Attachments: Originates from the surface of the iliac fossa and anterior inferior iliac spine. Its fibres combine with the tendon of the psoas major, inserting into the lesser trochanter of the femur. Actions: Flexion and lateral rotation of the thigh at the hip joint. Innervation: Femoral nerve (L2 – L4). Blood supply: Iliolumbar, deep circumflex iliac, obturator, and femoral arteries. By TeachMeSeries Ltd (2026) Fig 1Muscles of the posterior abdominal wall. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Pro Feature - Dissection Atlas The lumbar plexus, femoral nerve and muscles of the posterior abdominal wall. The lumbar plexus, femoral nerve and muscles of the posterior abdominal wall. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Frequent questions What is the iliacus muscle? The iliacus is a fan-shaped muscle located in the posterior abdominal wall, primarily responsible for flexing the thigh at the hip joint. It works in conjunction with the psoas major muscle to form the iliopsoas. Where does the iliacus muscle originate? The iliacus muscle originates from the iliac fossa and the anterior inferior iliac spine of the pelvis. These attachment points allow it to effectively contribute to hip flexion. What actions does the iliacus perform? The iliacus muscle is involved in the flexion and lateral rotation of the thigh at the hip joint. Its actions are crucial for movements such as walking and running. How is the iliacus muscle innervated? The iliacus is innervated by the femoral nerve, specifically from spinal segments L2 to L4. This nerve supply is essential for the muscle's function and coordination. What is the blood supply to the iliacus muscle? The blood supply to the iliacus muscle comes from the iliolumbar, deep circumflex iliac, obturator, and femoral arteries. These vessels ensure that the muscle receives adequate oxygen and nutrients for its activities. Rate This Article