Abstract
[Purpose] In this study, we elucidated the effects of different methods of visual perception (static and dynamic) on stepping-over motion during walking in a straight line or while turning 90 degrees. [Subjects] The participants were 31 healthy students. [Methods] The subjects performed tasks involving stepping over obstacles under four different conditions. In each condition, body sway measurements were taken immediately after subjects stepped over the obstacle, and clearance distance (between the subject's foot and the obstacle) during the stepping-over motion was measured. [Results] No significant differences in either rectangular area or root mean square area were seen for subjects' center of pressure among the conditions. Measurement of toe clearance showed that for both walking conditions (walking in a straight line and turning 90 degrees while walking towards the obstacle) the proximity of the limb to the obstacle was significantly closer in the dynamic than in the static condition. While turning 90 degrees, heel clearance during stepping-over motion was significantly closer to the obstacle in the dynamic condition than in the static condition. In the dynamic condition, heel clearance during stepping-over motion was significantly closer to the obstacle when turning 90 degrees than when walking in a straight line. [Conclusion] The results suggest that the multiple observations required to change locomotive direction, while approaching an obstacle in the travel path, allows the dimensional features of the object and the relationship between whole-body movements during locomotion and the obstacle to be perceived more three-dimensionally and more appropriately, contributing to improved kinematic control when stepping over the obstacle.
