Swing of the upper extremities during gait assists with:

Swing of the upper extremities during gait assists with:

• A. Reducing energy cost
• B. Counter-rotation
• C. Synchronization with trunk rotation
• D. Maintaining forward momentum

Answer: (B)

Arm swing during gait mainly provides counter-rotation between the upper and lower body segments. As one arm swings forward, the opposite arm swings back, helping offset the trunk and pelvis rotation produced by the legs. This opposite rotation stabilizes the torso and reduces whole-body angular momentum, which makes walking smoother and requires less muscular effort to control rotational movement. So while energy efficiency is a benefit, the primary role shown here is balancing rotation through counter-rotation. Synchronizing with the trunk would imply the same direction of rotation, which isn’t what happens, and maintaining forward momentum isn’t the primary mechanism either.

Arm swing during gait mainly provides counter-rotation between the upper and lower body segments. As one arm swings forward, the opposite arm swings back, helping offset the trunk and pelvis rotation produced by the legs. This opposite rotation stabilizes the torso and reduces whole-body angular momentum, which makes walking smoother and requires less muscular effort to control rotational movement. So while energy efficiency is a benefit, the primary role shown here is balancing rotation through counter-rotation. Synchronizing with the trunk would imply the same direction of rotation, which isn’t what happens, and maintaining forward momentum isn’t the primary mechanism either.