Background

It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements.

Research question

How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane?

Methods

Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed.

Results

In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC.

Significance

The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.

中文翻译：

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水平行走时经股骨窝内收对骨盆和躯干稳定性的影响——一项生物力学研究

背景

由于未受损腿的生理性内收股骨对齐，在内收时对齐经股骨假体窝是常见的做法。内收股骨和髋臼对齐有助于收紧髋外展肌以稳定骨盆并减少与骨盆和躯干相关的代偿运动。

研究问题

在额状面平地行走期间，经股骨窝的不同窝内收条件 (SAC) 如何影响骨盆和躯干的稳定性？

方法

七名中等残肢长度的经股截肢患者参与了这项研究。矢状面的假体对齐是根据既定的建议进行的。SAC 变化（0°、3°、6°、9°）。运动学和动力学参数是在步态实验室中记录的，其中有一个 12 相机光电系统和两个嵌入 12 米走道的压电测力台。测量是在水平地面行走时以自行选择的舒适步态速度进行的。

结果

在正面，几乎所有研究的运动学和动力学参数都与 SAC 有很强的相关性。在整个步态周期中，随着 SAC 的增加，骨盆在对侧升高。在假肢侧立阶段，平均肩斜度和平均侧向躯干向假肢侧倾斜，随着 SAC 的增加而降低。假肢侧髋外展力矩随着 SAC 的增加而减少。

意义

结果证实，经股骨 SAC 有助于骨盆稳定并减少骨盆和躯干的代偿运动。对于具有中等残肢长度的截肢者，6 ± 1° 的经股 SAC 用于长凳对齐似乎足够了。但是，个别患者的最佳值可能略有不同。