Effects of induced motor fatigue on walking mechanics and energetics
Effects of induced motor fatigue on walking mechanics and energetics
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诱发运动疲劳对步行力学和能量学的影响
DOI：
10.1016/j.jbiomech.2023.111688
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发表时间：
2023
影响因子：
2.4
通讯作者：
Yanco, Holly A.
中科院分区：
文献类型：
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作者：
Kao, Pei-Chun;Lomasney, Colin;Gu, Yan;Clark, Janelle P.;Yanco, Holly A.
下半身机器人外骨骼可用于减少运动的能量需求并增加穿戴者的耐力。了解运动疲劳如何影响行走性能可以导致更好的外骨骼设计，以支持由于运动疲劳而改变的个体的身体能力。本研究的目的是探讨运动疲劳对步行力学和能量学的影响。采用逐渐增加倾斜度的跑步机行走诱导运动疲劳。20名健康年轻受试者在运动疲劳前（PRE）和运动疲劳后（POST）以1.25 m/s和0°倾斜度在仪器化跑步机上行走5 min。我们检查了下肢关节力学，代谢成本和正机械功（η+功）的效率。与PRE相比，参与者在POST期间的净代谢能力增加了1.14%（p < 0.001）。在POST期间，参与者的总肢体正机械功率（总P+mech）也增加了1.4%（p < 0.001），导致η+功减少了1.8%（p < 0.001）。此外，POST期间下肢关节的正机械功贡献从踝关节转移到膝关节，而负机械功贡献从膝关节转移到踝关节（所有p < 0.017）。虽然产生更大的膝关节正机械功率以补偿运动疲劳后踝关节正功率的减少，但代谢成本的不成比例增加导致步行效率降低。这项研究的结果表明，动力踝关节可能有助于延迟发病的下肢关节工作重新分配观察运动疲劳。
Lower-body robotic exoskeletons can be used to reduce the energy demand of locomotion and increase the endurance of wearers. Understanding how motor fatigue affects walking performance may lead to better exoskeleton designs to support the changing physical capacity of an individual due to motor fatigue. The purpose of this study was to investigate the effects of motor fatigue on walking mechanics and energetics. Treadmill walking with progressively increased incline gradient was used to induce motor fatigue. Twenty healthy young participants walked on an instrumented treadmill at 1.25 m/s and 0° of incline for 5 min before (PRE) and after (POST) motor fatigue. We examined lower-limb joint mechanics, metabolic cost, and the efficiency of positive mechanical work (η+work). Compared to PRE, participants had increased net metabolic power by ∼14% (p < 0.001) during POST. Participants also had increased total-limb positive mechanical power (Total P+mech) by ∼4% during POST (p < 0.001), resulting in a reduced η+workby ∼8% (p < 0.001). In addition, the positive mechanical work contribution of the lower-limb joints during POST was shifted from the ankle to the knee while the negative mechanical work contribution was shifted from the knee to the ankle (all p < 0.017). Although greater knee positive mechanical power was generated to compensate for the reduction in ankle positive power after motor fatigue, the disproportionate increase in metabolic cost resulted in a reduced walking efficiency. The findings of this study suggest that powering the ankle joint may help delay the onset of the lower-limb joint work redistribution observed during motor fatigue.