Iliopsoas - Muscle Physiology & Functional Anatomy


Iliopsoas Muscle




  • Psoas Major

    • Transverse processes of T12-L5 & the lateral aspects of the intervertebral discs

  • Psoas Minor

    • Side of T12+L1 & IV intervertebral disc between

  • Iliacus

    • Iliac fossa, base of sacrum


  • Psoas Major

    • Lesser trochanter of the femur

  • Psoas Minor

    • Pectineal line & iliopectineal eminence (lesser trochanter of the femur)

  • Iliacus

    • Lesser trochanter of the femur (lowermost surface)

Major Arteries:

  • Psoas Major

    • Lumbar branch of iliolumbar artery

  • Psoas Minor

  • Iliacus

    • Medial femoral circumflex artery

    • Iliac branch of iliolumbar artery


Neural Innervation:

  • Psoas Major

    • Lumbar plexus via anterior branches of L1-L3 nerves

  • Psoas Minor

    • Lumbar plexus

  • Iliacus

    • Femoral nerve (L2-L3)


Trigger Points:

Iliopsoas Trigger Points





Concentric Functions:

  • Hip flexion & external rotation


Eccentric Functions:

  • Decelerates hip extension

  • Decelerates femoral internal rotation at heel strike


Isometric Function:

  • Assists in stabilizing the lumbar spine during functional movements


Related Muscles





More Images of the Iliopsoas Muscles

Psoas Major Psoas Minor Iliacus



More Information about the Iliopsoas Muscles

The illiopsoas muscle group includes the iliacus, psoas major & psoas minor.  The group is commonly referred to as the "hip flexors" as they are the muscles primarily responsible for flexing the hip, i.e. lifting your knee from a standing position as if to begin marching.


Back to Anatomy InformationFunctional Anatomy Chart