Abstract
[Purpose] The purpose of this study was to determine how younger and older adults modulate the center of pressure (COP) trajectory in the anteroposterior (A-P) and mediolateral (M-L) directions while stepping over an obstacle and during gait initiation (GI). [Subjects] Fifteen community-dwelling healthy older adults and fifteen healthy younger adults volunteered to participate in this study. [Methods] Subjects initiated gait or stepped over an obstacle at a self-paced speed with the right limb, in response to auditory cues. Performance was assessed by recording changes in the displacement of the COP in the A-P and M-L directions using two force plates. [Results] For combined test conditions, the A-P and M-L displacements of the COP in the older adults were significantly lower than the A-P and M-L displacements of the COP in the younger adults (p < 0.05). However, there were no significant differences between GI and stepping conditions for the COP shift (p > 0.05). [Conclusion] These findings suggest that a reduction in the magnitude of the COP shift with obstacle avoidance diminishes the ability of older adults to generate forward momentum and to maintain the lateral stability that is highly related to falls.
