Analyzing postural control during voluntary sway in the anteroposterior axis in young and elderly adults

摘要

Since human activities involve voluntary migration of center of foot pressure (CoP), dynamic stability of CoP may be an important factor for quantifying the quality of postural control. In the present study, ability to control CoP was evaluated in 20 young and 14 elderly adults by phase coupling analysis while subjects performing voluntary shifts of the CoP to the presented target which moves cyclically in the anteroposterior axis at constant period and magnitude. The coupling index between target and CoP trajectories and the amplitude of CoP movement decreased significantly in the elderly compared to young subjects. Moreover, coefficients of variations of those parameters were greater in the elderly. These results indicate that elderly people have a reduced ability to adjust their CoP to target and have a tendency to preserve safe margin.