The psoas major is a deep muscle located in the anterior hip and lumbar region that connects the lumbar spine to the femur. Together with the iliacus, it forms the iliopsoas, the primary hip flexor. The psoas major is essential for hip movement, spinal stability, posture, and efficient locomotion during activities such as walking, running, and climbing stairs.

Origin
The psoas major is a deep muscle located in the anterior hip and lumbar region that connects the lumbar spine to the femur. Together with the iliacus, it forms the iliopsoas, the primary hip flexor. The psoas major is essential for hip movement, spinal stability, posture, and efficient locomotion during activities such as walking, running, and climbing stairs.

Insertion
The psoas major inserts on the lesser trochanter of the femur by joining with the iliacus to form the common iliopsoas tendon.

Function

The primary function of the psoas major is hip flexion. It also flexes the trunk when the lower limbs are fixed, assists with lateral flexion of the lumbar spine, contributes to external rotation of the hip, and helps stabilize the lumbar spine and pelvis. These actions make the psoas major an important muscle for maintaining posture, supporting balance, and producing efficient movement during daily activities and athletic performance.

Hip Joint Flexion

Hanging Leg Raise