Iliopsoas
Hip & Pelvis
The most powerful hip flexor — and it's often tight from sitting all day, contributing to lower back pain.
Function
Flexes hip, laterally rotates thigh
Origin
Iliac fossa (iliacus) and T12-L5 vertebrae (psoas major)
Insertion
Lesser trochanter of femur
Innervation
Femoral nerve (L2-L4) and ventral rami L1-L3