What action does the quadratus femoris perform?

What action does the quadratus femoris perform?

• A. Medial Rotation
• B. Lateral Rotation
• C. Flexion
• D. Abduction

Answer: (B)

Understanding how the hip’s deep external rotators work helps explain this one. Quadratus femoris acts to rotate the thigh laterally at the hip joint; its fibers pull on the posterior aspect of the femur to turn the leg outward and help stabilize the hip by keeping the femoral head in the acetabulum. It does not primarily flex the hip, abduct it, or internally rotate the thigh, which is why lateral rotation is the correct action.

Understanding how the hip’s deep external rotators work helps explain this one. Quadratus femoris acts to rotate the thigh laterally at the hip joint; its fibers pull on the posterior aspect of the femur to turn the leg outward and help stabilize the hip by keeping the femoral head in the acetabulum. It does not primarily flex the hip, abduct it, or internally rotate the thigh, which is why lateral rotation is the correct action.