Figure 4. Stride modification effects of startling auditory stimulus on obstacle avoidance.

Mean percentages and standard deviation of stride shortening or lengthening for no startle and startle trials. Obstacle release phases were late stance (LSt), early swing (ESw) and mid-swing (MSw). *P < 0.05. Note: the number of trials in each condition was different (see Table 1) since there were few late stance trials in which subjects performed a short step strategy (or early swing and mid-swing trials in which subjects performed a long step strategy). This may partly explain why significance was only obtained for early swing and mid-swing in stride shortening.