The Ability of Young Adults to Change Walking Path During Preplanned and Unknown Condition when Attention is Divided

Dual task paradigm is a challenging condition for balance maintenance in our daily life. Changing walking path without prior knowledge of direction also creates hazard situation which requires subjects to make correct judgment instantly. The purpose of this study was to investigate the effects of divided attention and prior knowledge of walking path on ground reaction forces and sacral marker to center of pressure (COP) distance. Methods: Thirty-two young adults were recruited. The walking trials incorporated four condition-task combinations that each subject would encounter: planned side-step, single task (PS); planned side-step, dual task (PD); unknown side-step, single task (US); and unknown side-step, dual task (UD). Results: This study revealed that subjects decreased their peak lateral force and sacral marker-COP distance in the dual task trials. Subjects increased their peak lateral force, sacral marker-COP distance, and sacral marker velocity in the unknown condition. Conclusion: We concluded that the unpredictable change of the sidestep direction might bring the subjects into an unstable condition, while in the dual task trials, a conservative strategy was chosen.