The effect of lateral or medial wedges on control of postural sway in standing.

The objective of this study was to evaluate the effects of lateral and medial wedges on postural sway. Twenty healthy volunteers (mean age range of 28.45±3.34) participated in the study. They stood barefoot with eyes open or closed on each of the three surfaces: 10° lateral wedges, 10° medial wedges, and no wedges. Force platform data were collected and the mean and root mean square (RMS) distance, range, and velocity and the mean frequency of the center of pressure (COP) were calculated in the anterior-posterior (AP) and medial-lateral (ML) directions. Standing on both lateral and medial wedges was associated with improved postural stability seen through the decreased mean and RMS distance of COP displacement in ML direction. The results of this study suggest that standing on either lateral or medial wedges might enhance postural control in standing.