Sampaio de Oliveira Manuel Lucas, Uchida Thomas K
Department of Mechanical Engineering, University of Ottawa, 161 Louis-Pasteur, Ottawa, ON, K1N 6N5, Canada.
Ann Biomed Eng. 2025 May 6. doi: 10.1007/s10439-025-03742-x.
A lower-limb prosthesis is a mechanical device that replaces part of a biological limb to restore mobility. The tissues in the residual limb (the "residuum") experience atypical stresses. Importantly, the distal end of the residuum must bear the load that would typically be borne by the foot. To avoid pain and tissue damage, the part of the prosthesis that interfaces with the residuum (the "socket") must be designed to fit properly not only at rest but also during walking and other daily activities. The shape of the residuum changes during movement as muscles contract, which can affect the fit of the socket.
To study the residuum-socket interface, we created the first finite element model that considers the effect of muscle contraction on the residuum-socket interfacial pressure.
During gait, the interfacial pressure at heel strike and toe off was greater in key regions of the residuum when the gastrocnemius muscle was active rather than passive. The greatest difference was observed in the popliteal fossa region during heel strike, where the pressure was 42% greater when the muscle was fully active than when passive.
Our results provide insight into how muscle contraction affects socket fit throughout the gait cycle, potentially leading to improvements in the design and manufacture of prosthesis sockets.
下肢假肢是一种机械装置，用于替代生物肢体的一部分以恢复活动能力。残肢（“残端”）中的组织承受着非典型应力。重要的是，残端的远端必须承受通常由足部承受的负荷。为避免疼痛和组织损伤，与残端相接的假肢部件（“接受腔”）不仅在静止时，而且在行走和其他日常活动期间都必须设计成合适的形状。在运动过程中，随着肌肉收缩，残端的形状会发生变化，这可能会影响接受腔的贴合度。
为了研究残端-接受腔界面，我们创建了第一个考虑肌肉收缩对残端-接受腔界面压力影响的有限元模型。
在步态期间，当腓肠肌处于活跃而非被动状态时，残端关键区域在足跟触地和足趾离地时的界面压力更大。在足跟触地时，腘窝区域观察到的差异最大，当肌肉完全活跃时，该区域的压力比被动时高42%。
我们的结果为肌肉收缩如何在整个步态周期中影响接受腔贴合度提供了见解，这可能会导致假肢接受腔的设计和制造得到改进。
