During a typical stance phase, how many vertical GRF peaks are observed?

During a typical stance phase, how many vertical GRF peaks are observed?

• A. Two
• B. One
• C. Three
• D. None

Answer: (A)

In gait analysis, the vertical ground reaction force (GRF) during the stance phase typically shows two distinct peaks. The first peak occurs soon after heel contact as the limb accepts the body's weight during the loading response. The force then drops toward a minimum around midstance as the body passes over the foot. The second peak appears as the foot propels the body forward and prepares to toe off during the push-off/terminal stance phase. So there are two pronounced vertical GRF peaks per stance phase. A single peak would miss either the loading response or the push-off, three would indicate an extra peak not seen in normal gait, and none would imply no vertical force change, which isn’t accurate for stance.

In gait analysis, the vertical ground reaction force (GRF) during the stance phase typically shows two distinct peaks. The first peak occurs soon after heel contact as the limb accepts the body's weight during the loading response. The force then drops toward a minimum around midstance as the body passes over the foot. The second peak appears as the foot propels the body forward and prepares to toe off during the push-off/terminal stance phase. So there are two pronounced vertical GRF peaks per stance phase. A single peak would miss either the loading response or the push-off, three would indicate an extra peak not seen in normal gait, and none would imply no vertical force change, which isn’t accurate for stance.