Side-to-side COM displacement is partially seen clinically as which gait variable?

Side-to-side COM displacement is partially seen clinically as which gait variable?

• A. Step height
• B. Toe extension
• C. Hip extension angle only
• D. Step width

Answer: (D)

The side-to-side movement of the body's center of mass during walking is reflected in how wide the base of support is. Step width—the lateral distance between the feet—directly tracks this mediolateral control. When the center of mass shifts side to side, people naturally adjust by widening or narrowing their step width to maintain balance; a wider step width indicates greater lateral COM excursion and a larger need for stability. The other options describe motions in other planes or non-lateral aspects: step height is a vertical measure of how high the foot clears the ground, toe extension relates to the sagittal plane motion of the foot, and hip extension angle is a sagittal-plane hip motion. None of these capture the side-to-side displacement of the center of mass.

The side-to-side movement of the body's center of mass during walking is reflected in how wide the base of support is. Step width—the lateral distance between the feet—directly tracks this mediolateral control. When the center of mass shifts side to side, people naturally adjust by widening or narrowing their step width to maintain balance; a wider step width indicates greater lateral COM excursion and a larger need for stability.

The other options describe motions in other planes or non-lateral aspects: step height is a vertical measure of how high the foot clears the ground, toe extension relates to the sagittal plane motion of the foot, and hip extension angle is a sagittal-plane hip motion. None of these capture the side-to-side displacement of the center of mass.