Fig. 4.

Comparisons of the proactive and reactive a knee angle, b maximum BOS velocity, c relative COM position, d relative COM velocity, e step length, and f stability during the first and retest slips for all three cohorts. Knee joint angle was the one formed by thigh segment and the extension line of leg segment with flexion as positive. The knee angle was calculated for the leading leg. The step length was defined by the distance between left and right heels normalized by the body height with the forward direction as positive. *p < 0.05; ***p < 0.001