Effects of vision, age and gender on structural and global posturographic features during quiet standing

Gender differences have been reported in age-related deterioration of lateral balance, but only when subjects are assessed with their eyes open and only with global measures. The purpose of this study was to investigate the possible effects of vision on age-gender differences in static postural control with structural as well as global measures. Elderly and young subjects performed quiet natural standing on a force plate with their eyes open and closed. Structural measures based on sway-density, as well as conventional global measures, were derived from the center of pressure in both anterio-posterior (AP) and medio-lateral (ML) directions. Effects of vision, age and gender on each outcome measure were analyzed by ANOVA and post-hoc tests. Vision affected most outcome measures but gender-vision interactions could not be shown in both directions. Significant gender differences and age-gender interactions existed only in ML direction measures irrespective of vision. Specifically, women showed age-related reductions in stabilization time and increase in the distance between neighboring posturographic targets, as well as deterioration in global measures (p < 0.001). In conclusion, vision did not affect the age-gender differences in static postural control and women-specific age-related change in structural measures may suggest the deterioration in intermittent control.