The effect of prosthetic alignment on relative limb loading in persons with trans-tibial amputation: a preliminary report.

The prosthetic sockets of 14 independent persons with unilateral trans-tibial (BK) amputation were mounted on an adjustable alignment pylon. Vertical ground reaction forces were recorded in neutral prosthetic alignment and in 10 degrees of prosthetic socket varus, valgus, flexion, and extension. Stance phase time, peak vertical ground reaction force, and impulse were all found to be increased on the sound limb when compared to the amputated residual limb. Significant differences were found in stance phase time and peak vertical ground reaction force when comparing malaligned with neutrally aligned prosthetic limbs. Significant differences were also seen in impulse between neutrally aligned and malaligned prosthetic limbs. The results suggest that prosthetic malalignment in persons with trans-tibial amputation leads to increased loading of the contralateral limb.