We systematically investigate in-vivo the effect of increasing prosthetic knee flexion damping on key features of the swing phase of individuals with transfemoral amputation during walking. Five experienced prosthesis users walked using a prototype device in a motion capture laboratory. A range of interchangeable hydraulic rotary dampers was used to progressively modify swing phase flexion resistance in isolation. Toe clearance (TC; vertical distance toe to floor), effective leg length (ELL; distance hip to toe), and knee flexion angle during swing phase were computed, alongside the sensitivities of vertical toe position to angular displacements at the hip, knee and ankle. Key features of these profiles were compared across 5 damping conditions. With higher damping, knee extension occurred earlier in swing phase, promoting greater symmetry. However, with implications for toe catch, minimum TC reduced, and minimum TC and maximum ELL occurred earlier; temporally closer to mid-swing, when the limb must pass the stance limb. Further, TC became less sensitive to changes in hip flexion, suggesting a lesser ability to control toe clearance without employing proximal or contralateral compensations. There is a trade-off between key features related to gait safety when selecting an appropriate resistance for a mechanical prosthetic knee. In addition to highlighting broader implications surrounding swing phase damping selection for the optimization of mechanical knees, this work reveals design considerations that may be of utility in the formulation of control strategies for computerized devices.

中文翻译：

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膝关节摆动阶段屈曲阻力影响腿摆动的几个关键特征对安全经股假肢步态很重要

我们系统地调查 体内增加假肢膝关节屈曲阻尼对步行期间经股截肢患者摆动期关键特征的影响。五名经验丰富的假肢用户在动作捕捉实验室中使用原型设备行走。一系列可互换的液压旋转阻尼器用于逐步改变独立的摆动相屈曲阻力。计算了摆动阶段的脚趾间隙（TC；脚趾到地板的垂直距离）、有效腿长（ELL；臀部到脚趾的距离）和膝关节屈曲角度，以及垂直脚趾位置对臀部、膝盖和臀部角位移的敏感性。踝。在 5 种阻尼条件下比较了这些曲线的主要特征。阻尼越大，膝关节伸展发生在摆动阶段越早，从而促进更大的对称性。然而，对于脚趾抓地力的影响，最小 TC 降低，最小 TC 和最大 ELL 更早出现；时间上更接近摆动中期，此时肢体必须通过站立肢体。此外，TC 对髋关节屈曲的变化变得不那么敏感，这表明在不采用近端或对侧代偿的情况下控制脚趾间隙的能力较差。在为机械假肢膝盖选择合适的阻力时，需要在与步态安全相关的关键特征之间进行权衡。除了强调围绕摆动相阻尼选择对机械膝关节优化的更广泛影响之外，这项工作还揭示了可能对计算机化设备的控制策略制定有用的设计考虑因素。此外，TC 对髋关节屈曲的变化变得不那么敏感，这表明在不采用近端或对侧代偿的情况下控制脚趾间隙的能力较差。在为机械假肢膝盖选择合适的阻力时，需要在与步态安全相关的关键特征之间进行权衡。除了强调围绕摆动相阻尼选择对机械膝关节优化的更广泛影响之外，这项工作还揭示了可能对计算机化设备的控制策略制定有用的设计考虑因素。此外，TC 对髋关节屈曲的变化变得不那么敏感，这表明在不采用近端或对侧代偿的情况下控制脚趾间隙的能力较差。在为机械假肢膝盖选择合适的阻力时，需要在与步态安全相关的关键特征之间进行权衡。除了强调围绕摆动相阻尼选择对机械膝关节优化的更广泛影响之外，这项工作还揭示了可能对计算机化设备的控制策略制定有用的设计考虑因素。在为机械假肢膝盖选择合适的阻力时，需要在与步态安全相关的关键特征之间进行权衡。除了强调围绕摆动相阻尼选择对机械膝关节优化的更广泛影响之外，这项工作还揭示了可能对计算机化设备的控制策略制定有用的设计考虑因素。在为机械假肢膝盖选择合适的阻力时，需要在与步态安全相关的关键特征之间进行权衡。除了强调围绕摆动相阻尼选择对机械膝关节优化的更广泛影响之外，这项工作还揭示了可能对计算机化设备的控制策略制定有用的设计考虑因素。