During loading response, the external hip moment is what?

During loading response, the external hip moment is what?

• A. Flexion
• B. Abduction
• C. External rotation
• D. Extension

Answer: (A)

External moments at a joint come from forces outside the joint, notably the ground reaction force during walking. In loading response, the ground reaction force vector passes in front of the hip joint center, which creates a torque that tends to flex the hip (pulls the thigh forward). The body counteracts this by activating the hip extensors to control and slow the flexion. So the external hip moment is flexion. The other directions would require the ground reaction force to line up differently relative to the hip center, which isn’t the typical alignment during loading response.

External moments at a joint come from forces outside the joint, notably the ground reaction force during walking. In loading response, the ground reaction force vector passes in front of the hip joint center, which creates a torque that tends to flex the hip (pulls the thigh forward). The body counteracts this by activating the hip extensors to control and slow the flexion.

So the external hip moment is flexion. The other directions would require the ground reaction force to line up differently relative to the hip center, which isn’t the typical alignment during loading response.