What is the primary function of the iliopsoas muscle?

The primary function of the iliopsoas muscle is indeed hip flexion. The iliopsoas is composed of two muscles: the psoas major and the iliacus. The psoas major originates from the lumbar vertebrae and inserts into the lesser trochanter of the femur, while the iliacus originates from the iliac fossa of the pelvis and also inserts into the lesser trochanter. Together, these muscles play a crucial role in lifting the thigh toward the body or bending at the hip joint, which is essential for movements such as walking, running, and climbing.

In the context of lower limb mechanics, hip flexion is vital for various activities, making the iliopsoas muscle particularly important for maintaining mobility and gait. Understanding the iliopsoas muscle's role helps practitioners assess hip function and address any limitations in activities involving hip movement.