FRE 3405, AGIM (AGeing Imaging Modeling), CNRS-UJF-EPHE, Grenoble, France.
PLoS One. 2011;6(5):e19661. doi: 10.1371/journal.pone.0019661. Epub 2011 May 13.
The present study was designed to assess the relative contribution of each leg to unperturbed bipedal posture in lower limb amputees. To achieve this goal, eight unilateral traumatic trans-femoral amputees (TFA) were asked to stand as still as possible on a plantar pressure data acquisition system with their eyes closed. Four dependent variables were computed to describe the subject's postural behavior: (1) body weight distribution, (2) amplitude, (3) velocity and (4) regularity of centre of foot pressure (CoP) trajectories under the amputated (A) leg and the non-amputated (NA) leg. Results showed a larger body weight distribution applied to the NA leg than to the A leg and a more regular CoP profiles (lower sample entropy values) with greater amplitude and velocity under the NA leg than under the A leg. Taken together, these findings suggest that the NA leg and the A leg do not equally contribute to the control of unperturbed bipedal posture in TFA. The observation that TFA do actively control unperturbed bipedal posture with their NA leg could be viewed as an adaptive process to the loss of the lower leg afferents and efferents because of the unilateral lower-limb amputation. From a methodological point of view, these results demonstrate the suitability of computing bilateral CoP trajectories regularity for the assessment of lateralized postural control under pathological conditions.
本研究旨在评估每条腿对下肢截肢者无干扰双足姿势的相对贡献。为了实现这一目标，要求 8 名单侧创伤性股骨截肢（TFA）患者尽可能闭上眼睛站在足底压力数据采集系统上，以保持静止。计算了四个依赖变量来描述受试者的姿势行为：（1）体重分布，（2）振幅，（3）速度和（4）足部压力中心（CoP）轨迹的规则性，分别在截肢（A）腿和非截肢（NA）腿下。结果表明，NA 腿的体重分布大于 A 腿，NA 腿的 CoP 轨迹更规则（较低的样本熵值），振幅和速度大于 A 腿。综上所述，这些发现表明，NA 腿和 A 腿在控制 TFA 无干扰双足姿势方面的贡献并不均等。TFA 积极用他们的非截肢腿控制无干扰双足姿势的观察结果可以被视为对单侧下肢截肢导致的下肢传入和传出神经丧失的一种适应过程。从方法学的角度来看，这些结果证明了计算双侧 CoP 轨迹规则性来评估病理条件下的偏侧姿势控制的适用性。
