Which muscle acts as a hip flexor?

• A. Iliopsoas
• B. Rectus Femoris
• C. Pectineus
• D. Tensor Fasciae Latae

Answer: (A)

Hip flexion means lifting the thigh toward the trunk at the hip joint. The iliopsoas is the primary hip flexor because it crosses the hip joint and provides the most powerful flexion, especially from a standing start. It’s made up of two muscles—the psoas major and the iliacus—that combine to pull the femur forward and help stabilize the pelvis.

Other muscles listed can assist hip flexion but aren’t the main drivers: the rectus femoris can flex the hip but its main action is knee extension (it crosses both the hip and knee), the pectineus is a smaller hip flexor and adductor, and the tensor fasciae latae also helps with hip flexion but mainly assists with stabilization and abduction. So the best choice for a hip flexor is the iliopsoas.