Pickle Nathaniel T, Grabowski Alena M, Jeffers Jana R, Silverman Anne K
Department of Mechanical Engineering, Colorado School of Mines, 1500 Illinois St, Golden, CO 80401 e-mail: .
Department of Integrative Physiology, University of Colorado, 354 UCB, Boulder, CO 80309.
J Biomech Eng. 2017 Nov 1;139(11):1110051-11100511. doi: 10.1115/1.4037938.
Sloped walking is challenging for individuals with transtibial amputation (TTA) due to the functional loss of the ankle plantarflexors. Prostheses that actively generate ankle power may help to restore this lost function. The purpose of this study was to use musculoskeletal modeling and simulation to quantify the mechanical power delivered to body segments by passive and powered prostheses and the remaining muscles in the amputated and intact legs during sloped walking. We generated walking simulations from experimental kinematic and kinetic data on slopes of 0, ±3 deg and ±6 deg in eight people with a TTA using powered and passive prostheses and eight nonamputees. Consistent with our hypothesis, the amputated leg hamstrings generated more power to both legs on uphill slopes in comparison with nonamputees, which may have implications for fatigue or overuse injuries. The amputated leg knee extensors delivered less power to the trunk on downhill slopes (effect size (ES) ≥ 1.35, p ≤ 0.02), which may be due to muscle weakness or socket instability. The power delivered to the trunk from the powered and passive prostheses was not significantly different (p > 0.05), However, using the powered prosthesis on uphill slopes reduced the contributions from the amputated leg hamstrings in all segments (ES ≥ 0.46, p ≤ 0.003), suggesting that added ankle power reduces the need for the hamstrings to compensate for lost ankle muscle function. Neither prosthesis replaced gastrocnemius function to absorb power from the trunk and deliver it to the leg on all slopes.
对于经胫骨截肢（TTA）患者而言，由于踝跖屈肌功能丧失，斜坡行走具有挑战性。能够主动产生踝关节力量的假肢可能有助于恢复这种丧失的功能。本研究的目的是使用肌肉骨骼建模和模拟来量化在斜坡行走过程中，被动和动力假肢以及截肢腿和健侧腿中其余肌肉传递到身体各节段的机械功率。我们根据8名使用动力和被动假肢的TTA患者以及8名非截肢者在0°、±3°和±6°斜坡上的实验运动学和动力学数据生成了行走模拟。与我们的假设一致，与非截肢者相比，截肢腿的腘绳肌在上坡时向双腿产生了更多功率，这可能对疲劳或过度使用损伤有影响。截肢腿的膝伸肌在下坡时向躯干传递的功率较小（效应大小（ES）≥1.35，p≤0.02），这可能是由于肌肉无力或接受腔不稳定。动力假肢和被动假肢传递到躯干的功率没有显著差异（p>0.05）。然而，在上坡时使用动力假肢减少了截肢腿腘绳肌在所有节段的贡献（ES≥0.46，p≤0.003），这表明增加的踝关节力量减少了腘绳肌补偿丧失的踝关节肌肉功能的需求。在所有坡度下，两种假肢都无法替代腓肠肌的功能，即从躯干吸收能量并传递到腿部。
