Effect of manipulation of the feet and ankles on postural control in elderly adults.

The purpose of the present experiment was to investigate the effect of a therapeutic manipulation of the feet and ankles on postural control during quiet standing in elderly adults. Seventeen elderly adults stood barefeet on a force platform and were asked to sway as little as possible. Within a trial, vision was suppressed by eyes closure. The task was executed in two experimental sessions: before and after a therapeutic manipulation of the feet and ankles. Centre of feet pressure (COP) displacements along the mediolateral (ML) and anteroposterior (AP) axes were recorded. For the two experimental sessions, subjects exhibited comparable COP displacements when vision was available and were similarly affected by the suppression of vision. However, when subjects had to adapt to the absence of vision within a 10s temporal frame, postural behaviour became different in the two experimental sessions: the sum of the ML and AP COP displacements increased within the 10s temporal frame before the therapeutic manipulation of the feet and ankles, whereas it remained unchanged after it. These results suggested that the therapeutic manipulation of the feet and ankles allows the elderly adults to partially compensate for the destabilising effect induced by the suppression of vision.