When is the gluteus maximus' force potential greatest?

• A. Greatest when the hip is at a neutral position
• B. Greatest when the hip is in full extension
• C. Greatest when the hip is in full flexion
• D. Greatest with the knee flexed

Answer: (C)

Muscle force production depends on how long the muscle is and how its pull translates into joint torque at that moment. The gluteus maximus is the main hip extensor, and its ability to generate hip extension torque is best when the hip is in deep flexion. In full flexion, the muscle is stretched across the hip and can produce a strong extension torque as it shortens during movement, aided by a favorable line of pull and lever arm. As the hip moves toward neutral or into full extension, the gluteus maximus becomes relatively shortened, reducing its leverage and the amount of force it can generate. The position of the knee has less direct impact on the gluteus maximus’ ability to produce hip extension torque.