Thresholded scatterplot of individual subject minimum obstacle distances on visible obstacles surface by subject group. Median of the minimum obstacle distance for all steps at each instructed gait speed (slow, preferred, and fast) on the surface with visible obstacles. As gait speed is not indicated on this figure, three points are shown for each subject. If a 35mm threshold (tightly-spaced dashes) is applied to categorize subjects as “normal foot placement” or “active avoiders”, 29% of older men (all speeds for two subjects) and 57% of older women (all speeds for three subjects and one or two speeds for two others) would be considered to be actively avoiding the obstacles. If this threshold is raised to 45mm (loosely-spaced dashes) then 52% of the older females (one less speed for subject 4) would still be considered to be actively avoiding the obstacles while all but one of the older male conditions would not. Five percent of both younger subject groups and older men (preferred speed for one subject from each group) had a minimum obstacle distance value above both thresholds.