Hanger Clinic, 3508 12th Ave NE, Olympia, WA 98506, USA.
Center for Limb Loss and MoBility, VA Puget Sound Health Care System, 1660 S Columbian Way, Seattle, WA 98108, USA; Department of Rehabilitation Medicine, University of Washington, 1959 NE Pacific Street, Box 356490, Seattle, WA 98195, USA.
J Biomech. 2024 Nov;176:112368. doi: 10.1016/j.jbiomech.2024.112368. Epub 2024 Oct 16.
Lower limb prosthesis users are at an increased risk of developing osteoarthritis in their intact knee. There is a scarcity of literature examining how the stiffness properties of commercially available prosthetic feet impact gait mechanics, including knee loading biomechanical variables that have been associated with the development of osteoarthritis. This study aimed to isolate the effect of commercial prosthetic foot stiffness on intact knee loading, prosthetic foot-ankle biomechanics, and user perception. Seventeen males with unilateral transtibial amputation were fit with three consecutive foot stiffness categories of a standardized energy-storing prosthetic foot in a randomized order and while blinded to foot condition. Biomechanical and self-report data were collected during level-ground walking in a motion analysis laboratory. As prosthetic foot stiffness increased, contralateral knee external adduction moment significantly decreased between stiff vs. medium and stiff vs. soft foot conditions. Prosthetic foot rollover radius increased as foot stiffness increased. However, prosthetic foot-ankle push-off peak power and work decreased as foot stiffness increased. On average, users favored the medium stiffness condition and were able to correctly identify the foot stiffness condition. Overall, these results raise questions about the relative contributions of foot stiffness and ankle push-off power to changes in contralateral knee loading. The findings contribute to our understanding of the relationships between prosthetic foot mechanical properties and gait biomechanical variables at the contralateral knee when prosthetic foot stiffness is modified without a corresponding alignment adjustment.
下肢假肢使用者其完好膝关节患骨关节炎的风险增加。目前，研究商业可用假肢脚的刚度如何影响步态力学的文献很少，包括与骨关节炎发展相关的膝关节加载生物力学变量。本研究旨在分离商业假肢脚刚度对完好膝关节加载、假肢脚-踝生物力学和使用者感知的影响。17 名单侧胫骨截肢男性以随机顺序和盲法接受三种连续的标准化储能假肢脚刚度类别，并在运动分析实验室进行水平地面行走时收集生物力学和自我报告数据。随着假肢脚刚度的增加，与中硬脚和软硬脚相比，对侧膝关节外展力矩显著减小。随着脚刚度的增加，假肢脚滚动半径增大。然而，随着脚刚度的增加，假肢脚-踝推离峰值功率和功减小。平均而言，使用者更喜欢中硬度条件，并且能够正确识别脚的硬度条件。总的来说，这些结果引发了对脚刚度和踝推离功率对相对贡献的质疑，以改变对侧膝关节的加载。这些发现有助于我们理解在不进行相应的对准调整的情况下改变假肢脚刚度时，假肢脚机械性能与对侧膝关节步态生物力学变量之间的关系。
