Article

In human subjects, leg amputation impairs upright quiet-stance
control. The inability to exert appropriate force reactions under the amputated
leg and a slight weight-bearing asymmetry cause the amputee to develop
compensatory mechanisms through the sound leg. This study is aimed at assessing
these mechanisms and the influence of the level of amputation. DESIGN: The postural strategies of transtibial and transfemoral amputees for maintaining
quiet stance were investigated using a dual-force platform. With this device,
mean body weight distribution and plantar and resultant center of pressure
trajectories can be measured and used to assess the likely compensatory
mechanisms. RESULTS: Compensatory strategies were found in both transtibial and
transfemoral groups, with a forward shift of the mean positions of the center of
pressure under the amputated leg and greater resultant center of pressure
displacements appearing along the anteroposterior axis, respectively. The
transfemoral group presents a larger center of pressure displacements under the
amputated leg than the transtibial group. CONCLUSION: These data emphasize the
role played by the differences between the center-of-pressure magnitudes
intervening under the sound and amputated legs and the size of the
prosthesis-stump contact area in these postural strategies.

Langue : ANGLAIS