Internal torques during gait are generally created by what mechanism?

Internal torques during gait are generally created by what mechanism?

• A. The opposite limb only
• B. Muscle activation resisting or controlling external torque
• C. Gravity only
• D. Ground pushing on the foot only

Answer: (B)

Movement at the joints in gait is driven by what muscles actively do to oppose external influences. Internal joint torques are generated when muscle activation creates moments around the joints to resist or control the external torques produced by gravity and the ground reaction forces through the foot. In other words, the muscles contract to counter or modulate the forces trying to rotate a joint, shaping the movement and keeping joints stable. Think of it this way: gravity and ground contact produce external torques that would move the joints in a certain direction. The muscles then activate to generate an opposing (internal) torque, which can be concentric to produce motion or eccentric to control it. That muscle-driven opposition is what forms the internal torques you measure during gait. The other ideas don’t explain the source of the internal moment. The opposite limb isn’t what creates the internal torque in a given joint, gravity alone isn’t generating internal moments, and ground pushing on the foot is an external input rather than the source of the muscle-driven internal torque.

Movement at the joints in gait is driven by what muscles actively do to oppose external influences. Internal joint torques are generated when muscle activation creates moments around the joints to resist or control the external torques produced by gravity and the ground reaction forces through the foot. In other words, the muscles contract to counter or modulate the forces trying to rotate a joint, shaping the movement and keeping joints stable.

Think of it this way: gravity and ground contact produce external torques that would move the joints in a certain direction. The muscles then activate to generate an opposing (internal) torque, which can be concentric to produce motion or eccentric to control it. That muscle-driven opposition is what forms the internal torques you measure during gait.

The other ideas don’t explain the source of the internal moment. The opposite limb isn’t what creates the internal torque in a given joint, gravity alone isn’t generating internal moments, and ground pushing on the foot is an external input rather than the source of the muscle-driven internal torque.