Background

Subjects with transfemoral amputation (TFA) show an asymmetric gait pattern associated with a decreased ability to recover mechanical energy and an increased metabolic cost of walking.

Research question

This study aimed to identify the spatio-temporal and kinematic gait variables correlated with mechanical energy values in subjects with TFA and to observe the ability of the identified parameters to discriminate between TFA and controls according to the type of prosthesis.

Methods

The gait of 40 subjects with TFA was evaluated with a motion 3-D optoelectronic system. Nine subjects wore a mechanical prosthesis (TFAm), seventeen a C-Leg prosthesis (TFAc), and fourteen a Genium prosthesis (TFAg). Spatio-temporal and pelvic kinematic parameters were measured. Energy recovery was measured relative to the whole-body center of mass (CoM) kinematics as the fraction of mechanical energy recovered during each walking step (R-step). Correlation tests and multiple linear regression analyses were used to evaluate the correlation and association between kinematic and energy variables, respectively. Receiver operating characteristics curves were plotted to assess the ability of the correlated parameter to distinguish subjects with TFA from controls, and optimal cutoff point values were calculated according to the type of prosthesis.

Results

Among the spatio-temporal and kinematic parameters correlated to R-step, only pelvic obliquity of the prosthetic side was significantly associated with R-step. It showed an excellent ability to discriminate between TFA and controls. Furthermore, pelvic obliquity showed an excellent discriminative ability in identifying TFAm and TFAc and a good discriminative ability in identifying TFAg from controls.

Significance

Pelvic obliquity plays an important role in energy recovery during gait for subjects using prosthetics. This information might be exploited to monitor the adaptation of subjects with TFA to prosthetic devices, to lower the energetic cost of walking potentially, and to reduce the long-term risks of secondary physical complications in prosthetic users.

中文翻译：

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骨盆倾斜作为导致能量回收率较低的补偿机制：经股截肢患者假体类型的表征。

背景

经股截肢（TFA）的受试者表现出步态不对称，与恢复机械能的能力降低和步行的代谢成本增加有关。

研究问题

这项研究的目的是确定与TFA患者的机械能值相关的时空和运动步态变量，并观察所识别参数根据假体类型区分TFA和对照的能力。

方法

使用运动3-D光电系统评估了40名患有TFA的受试者的步态。九名受试者佩戴了机械假体（TFAm），十七名佩戴了C型腿假体（TFAc），十四名佩戴了Genium假体（TFAg）。测量时空和骨盆运动学参数。相对于全身质心（CoM）运动学测量能量回收率，作为每个步行步骤（R步骤）中回收的机械能的一部分。相关性测试和多元线性回归分析分别用于评估运动学变量和能量变量之间的相关性和关联性。绘制受试者工作特征曲线以评估相关参数区分TFA受试者与对照组的能力，并根据假体类型计算最佳截止点值。

结果

在与R步相关的时空和运动学参数中，仅假肢的骨盆倾斜与R步显着相关。它显示出出色的区分TFA和对照的能力。此外，骨盆倾斜在鉴别TFAm和TFAc方面表现出极好的判别能力，并且在从对照中鉴别TFAg方面表现出良好的判别能力。

意义

骨盆倾斜在使用假肢的受试者步态期间能量恢复中起重要作用。可以利用此信息来监视患有TFA的受试者对假肢设备的适应性，以降低潜在的步行能量消耗，并减少假肢使用者继发身体并发症的长期风险。