Fig. 2
Slipping and stumbling perturbation profiles at a frame rate of 100 Hz were synchronized by D-Flow software based on kinematic acquisition frequency. All perturbations occurred at the moment of right heel strike with the belt. The slip perturbation was a belt acceleration of 3 m/s2, increasing 1.2 m/s over the subject’s normal gait velocity, holding for 300 ms, and then decelerating to normal velocity, while the fall perturbation was the opposite and decreased the velocity to a minimum value of 0. The schematic is the curve generated with the participant’s average velocity of 1.32 m/s. The x and y axes represent the time and speed offsets, respectively