Iliopsoas muscle

The iliopsoas muscle is found within the iliopsoas compartment and is an important muscle in locomotion and upright posture.

Summary

• origin: fusion of psoas major and iliacus muscles
• insertion: lesser trochanter of the femur
• nerve supply: femoral nerve; lumbar plexus
• blood supply: iliolumbar artery; medial femoral circumflex artery
• action: flexor of the hip and trunk; lateral flexor of the trunk

Gross anatomy

Origin

The iliopsoas muscle has its origin at the fusion of the psoas major and iliacus muscles. This fusion occurs at the level of L5-S2, and the combined muscles pass from the pelvis to the thigh under the inguinal ligament.

Insertion

The iliopsoas muscle inserts into the lesser trochanter of the femur via the psoas tendon.

Innervation

• femoral nerve (iliacus part)
• direct branches of the lumbar plexus (psoas part)