Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, United States of America.
Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States of America.
PLoS One. 2024 May 17;19(5):e0295465. doi: 10.1371/journal.pone.0295465. eCollection 2024.
Walking on sloped surfaces is challenging for many lower limb prosthesis users, in part due to the limited ankle range of motion provided by typical prosthetic ankle-foot devices. Adding a toe joint could potentially benefit users by providing an additional degree of flexibility to adapt to sloped surfaces, but this remains untested. The objective of this study was to characterize the effect of a prosthesis with an articulating toe joint on the preferences and gait biomechanics of individuals with unilateral below-knee limb loss walking on slopes. Nine active prosthesis users walked on an instrumented treadmill at a +5° incline and -5° decline while wearing an experimental foot prosthesis in two configurations: a Flexible toe joint and a Locked-out toe joint. Three participants preferred the Flexible toe joint over the Locked-out toe joint for incline and decline walking. Eight of nine participants went on to participate in a biomechanical data collection. The Flexible toe joint decreased prosthesis Push-off work by 2 Joules during both incline (p = 0.008; g = -0.63) and decline (p = 0.008; g = -0.65) walking. During incline walking, prosthetic limb knee flexion at toe-off was 3° greater in the Flexible configuration compared to the Locked (p = 0.008; g = 0.42). Overall, these results indicate that adding a toe joint to a passive foot prosthesis has relatively small effects on joint kinematics and kinetics during sloped walking. This study is part of a larger body of work that also assessed the impact of a prosthetic toe joint for level and uneven terrain walking and stair ascent/descent. Collectively, toe joints do not appear to substantially or consistently alter lower limb mechanics for active unilateral below-knee prosthesis users. Our findings also demonstrate that user preference for passive prosthetic technology may be both subject-specific and task-specific. Future work could investigate the inter-individual preferences and potential benefits of a prosthetic toe joint for lower-mobility individuals.
在倾斜表面上行走对许多下肢假肢使用者来说具有挑战性，部分原因是典型的假肢踝足装置提供的踝关节活动范围有限。添加脚趾关节可以通过为适应倾斜表面提供额外的灵活性来使使用者受益，但这尚未得到验证。本研究的目的是描述一种带有铰接脚趾关节的假肢对单侧膝下截肢者在斜坡上行走的偏好和步态生物力学的影响。9 名活跃的假肢使用者在仪器化跑步机上以+5°的坡度和-5°的坡度行走，同时穿着实验性脚假肢，有两种配置：柔性脚趾关节和锁定脚趾关节。在倾斜和下降行走时，有 3 名参与者更喜欢柔性脚趾关节而不是锁定脚趾关节。9 名参与者中有 8 名继续参与生物力学数据收集。在倾斜和下降行走时，柔性脚趾关节分别使假肢的推离功减少了 2 焦耳（p = 0.008；g = -0.63）和（p = 0.008；g = -0.65）。在上升行走时，柔性配置中在脚趾离地时的假肢膝关节屈曲比锁定配置大 3°（p = 0.008；g = 0.42）。总体而言，这些结果表明，为被动脚假肢添加脚趾关节对倾斜行走时的关节运动学和动力学有相对较小的影响。本研究是更大的研究工作的一部分，该工作还评估了假肢脚趾关节对水平和不平坦地形行走以及上下楼梯的影响。总的来说，脚趾关节似乎不会显著或一致地改变主动单侧膝下假肢使用者的下肢力学。我们的研究结果还表明，用户对被动假肢技术的偏好可能是特定于个体和特定于任务的。未来的工作可以研究个体间对假肢脚趾关节的偏好以及对下肢活动能力较低的个体的潜在益处。
