Figure 3

Set-up of the foot placement accuracy protocol. Subjects were required to walk along the pathway at self-selected pace and place the right foot into target 1 (Condition 1 (a)), place the right foot into target 1 and the left foot into target 2 (Condition 2 (b)), and additionally step over an obstacle lying between the two targets (Condition 3 (c)). The target(s) appeared in two possible positions separated medio-laterally by 8 cm to prevent task familiarization (d). Video still of camera 2 during stance phase used to evaluate the lateral and posterior distance error (e).