Which muscle is associated with hip flexion?

The psoas muscle plays a crucial role in hip flexion. It is a deep-seated muscle that connects the lumbar vertebrae to the femur and is part of the iliopsoas group, which is considered the primary hip flexor. When the psoas contracts, it pulls the thigh toward the body, allowing the leg to lift and bend at the hip. This action is fundamental in various movements, including walking, running, and performing many Pilates exercises.

While other muscles are involved in hip movement, they do not primarily function as hip flexors. For example, the rectus femoris, part of the quadriceps group, assists in hip flexion but is not the main hip flexor and is primarily known for extending the knee. The gluteus maximus, known for its role in hip extension, primarily works to extend the hip rather than flex it, while the hamstrings are primarily involved in hip extension and knee flexion. Thus, the psoas stands out as the key muscle primarily responsible for hip flexion.