Leg-length discrepancy: effect on the amplitude of postural sway.

The purpose of this study was to investigate whether leg-length discrepancy (LLD) influences a person's standing balance as measured by the amplitude of his/her postural sway. Twenty volunteers between the ages of 20 and 32 participated. Eleven individuals with no measurable LLD constituted the control group. The experimental group consisted of nine individuals with at least a 9.5mm LLD. Each subject stood barefoot on a force platform with their feet together. Center-of-pressure data were collected at a rate of 10Hz for 12.8 seconds while the subjects stood with their eyes opened and again with their eyes closed. The amplitude of each person's postural sway in the medial-lateral and anterior-posterior directions was calculated from the center-of-pressure data. The results of the study showed that no significant difference existed between the experimental and control groups. There was, however, a significant difference (p less than .05) between the conditions of eyes opened and closed. These results indicate that individuals with an LLD do not have more postural sway than those without an LLD.