Peak vertical GRF is approximately what percentage of body weight?

Peak vertical GRF is approximately what percentage of body weight?

• A. 120% BW
• B. 20% BW
• C. 5% BW
• D. 60% BW

Answer: (A)

When we look at how the body interacts with the ground during walking, the vertical ground reaction force rises to a peak as the foot lands and the leg absorbs the body's weight. That peak needs to be greater than body weight because the ground must not only support gravity but also decelerate the downward motion of the body during the loading response. A typical walking peak is around 1.2 times body weight, i.e., about 120% BW. This reflects the combination of supporting the body and absorbing impact in a short moment after contact. The other options—much smaller values—don’t reflect the substantial loading that occurs at heel strike. Remember, faster activities like running produce even higher peaks, often 2–3 times body weight.

When we look at how the body interacts with the ground during walking, the vertical ground reaction force rises to a peak as the foot lands and the leg absorbs the body's weight. That peak needs to be greater than body weight because the ground must not only support gravity but also decelerate the downward motion of the body during the loading response. A typical walking peak is around 1.2 times body weight, i.e., about 120% BW. This reflects the combination of supporting the body and absorbing impact in a short moment after contact. The other options—much smaller values—don’t reflect the substantial loading that occurs at heel strike. Remember, faster activities like running produce even higher peaks, often 2–3 times body weight.