Eagen Finn G, Fey Nicholas P
Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
Texas Robotics Consortium, The University of Texas at Austin, Austin, TX, USA.
Wearable Technol. 2025 Mar 12;6:e16. doi: 10.1017/wtc.2025.5. eCollection 2025.
The muscular restructuring and loss of function that occurs during a transfemoral amputation surgery has a great impact on the gait and mobility of the individual. The hip of the residual limb adopts a number of functional roles that would previously be controlled by lower joints. In the absence of active plantar flexors, swing initiation must be achieved through an increased hip flexion moment. The high activity of the residual limb is a major contributor to the discomfort and fatigue experienced by individuals with transfemoral amputations during walking. In other patient populations, both passive and active hip exosuits have been shown to positively affect gait mechanics. We believe an exosuit configured to aid with hip flexion could be well applied to individuals with transfemoral amputation. In this article, we model the effects of such a device during whole-body, subject-specific kinematic simulations of level ground walking. The device is simulated for 18 individuals of K2 and K3 Medicare functional classification levels. A user-specific device profile is generated via a three-axis moment-matching optimization using an interior-point algorithm. We employ two related cost functions that reflect an active and passive form of the device. We hypothesized that the optimal device configuration would be highly variable across subjects but that variance within mobility groups would be lower. From the results, we partially accept this hypothesis, as some parameters had high variance across subjects. However, variance did not consistently trend down when dividing into mobility groups, highlighting the need for user-specific design.
经股截肢手术过程中发生的肌肉重构和功能丧失对个体的步态和移动能力有很大影响。残肢的髋关节承担了一些以前由下肢关节控制的功能角色。在没有主动跖屈肌的情况下，摆动起始必须通过增加髋关节屈曲力矩来实现。残肢的高活动度是经股截肢患者行走时感到不适和疲劳的主要原因。在其他患者群体中，被动和主动髋关节外骨骼都已被证明对步态力学有积极影响。我们认为，一种配置为辅助髋关节屈曲的外骨骼可以很好地应用于经股截肢患者。在本文中，我们在平地行走的全身、个体特定运动学模拟中对这种装置的效果进行建模。该装置针对18名K2和K3医疗保险功能分级水平的个体进行模拟。通过使用内点算法的三轴力矩匹配优化生成用户特定的装置配置文件。我们采用两个相关的成本函数，分别反映装置的主动和被动形式。我们假设，最佳装置配置在不同个体之间会有很大差异，但在移动性组内的差异会较小。从结果来看，我们部分接受了这个假设，因为一些参数在不同个体之间有很大差异。然而，在划分移动性组时，差异并没有持续下降的趋势，这突出了用户特定设计的必要性。
