Tacca Joshua R, Colvin Zane A, Grabowski Alena M
Paul M. Rady Department of Mechanical Engineering, University of Colorado, Boulder, CO, United States.
Department of Integrative Physiology, University of Colorado, Boulder, CO, United States.
Front Bioeng Biotechnol. 2024 Jul 1;12:1336520. doi: 10.3389/fbioe.2024.1336520. eCollection 2024.
People with unilateral transtibial amputation (TTA) using a passive-elastic prosthesis exhibit lower positive affected leg trailing work (AL W) and a greater magnitude of negative unaffected leg leading work (UL W) during walking than non-amputees, which may increase joint pain and osteoarthritis risk in the unaffected leg. People with TTA using a stance-phase powered prosthesis (e.g., BiOM, Ottobock, Duderstadt, Germany) walk with increased AL W and potentially decreased magnitude of UL W compared to a passive-elastic prosthesis. The BiOM includes a passive-elastic prosthesis with a manufacturer-recommended stiffness category and can be tuned to different power settings, which may change AL W UL W and the prosthesis effective foot length ratio (EFLR). Thirteen people with TTA walked using 16 different prosthetic stiffness category and power settings on a level treadmill at 0.75-1.75 m/s. We constructed linear mixed effects models to determine the effects of stiffness category and power settings on AL W UL W and EFLR and hypothesized that decreased stiffness and increased power would increase AL W, not change and decrease UL W magnitude, and decrease and not change prosthesis EFLR, respectively. We found there was no significant effect of stiffness category on AL W but increased stiffness reduced UL W magnitude, perhaps due to a 0.02 increase in prosthesis EFLR compared to the least stiff category. Furthermore, we found that use of the BiOM with 10% and 20% greater than recommended power increased AL W and decreased UL W magnitude at 0.75-1.00 m/s. However, prosthetic power setting depended on walking speed so that use of the BiOM increased UL W magnitude at 1.50-1.75 m/s compared to a passive-elastic prosthesis. Ultimately, our results suggest that at 0.75-1.00 m/s, prosthetists should utilize the BiOM attached to a passive-elastic prosthesis with an increased stiffness category and power settings up to 20% greater than recommended based on biological ankle values. This prosthetic configuration can allow people with unilateral transtibial amputation to increase AL W and minimize UL W magnitude, which could reduce joint pain and osteoarthritis risk in the unaffected leg and potentially lower the metabolic cost of walking.
与非截肢者相比，使用被动弹性假肢的单侧经胫骨截肢（TTA）患者在行走过程中患侧腿的正向拖曳功（AL W）较低，而健侧腿的负向引导功（UL W）幅度较大，这可能会增加健侧腿的关节疼痛和骨关节炎风险。与被动弹性假肢相比，使用站立期动力假肢（如德国杜德施塔特的BiOM、奥托博克）的TTA患者行走时AL W增加，UL W幅度可能减小。BiOM包括一个具有制造商推荐刚度类别的被动弹性假肢，并且可以调整到不同的功率设置，这可能会改变AL W、UL W和假肢有效脚长比（EFLR）。13名TTA患者在水平跑步机上以0.75 - 1.75米/秒的速度使用16种不同的假肢刚度类别和功率设置行走。我们构建了线性混合效应模型，以确定刚度类别和功率设置对AL W、UL W和EFLR的影响，并假设降低刚度和增加功率将分别增加AL W、不改变并降低UL W幅度，以及降低并保持假肢EFLR不变。我们发现刚度类别对AL W没有显著影响，但增加刚度会降低UL W幅度，这可能是由于与最软刚度类别相比，假肢EFLR增加了0.02。此外，我们发现，在0.75 - 1.00米/秒的速度下，使用比推荐功率高10%和20%的BiOM会增加AL W并降低UL W幅度。然而，假肢功率设置取决于行走速度，因此与被动弹性假肢相比，在1.50 - 1.75米/秒的速度下使用BiOM会增加UL W幅度。最终，我们的结果表明，在0.75 - 1.00米/秒的速度下，假肢技师应使用与被动弹性假肢相连的BiOM，其刚度类别增加，功率设置比基于生物脚踝值推荐的功率高20%。这种假肢配置可以使单侧经胫骨截肢患者增加AL W并最小化UL W幅度，这可以减少健侧腿的关节疼痛和骨关节炎风险，并可能降低行走的代谢成本。
