Factors in fatigue during intermittent electrical stimulation of human skeletal muscle.
Factors in fatigue during intermittent electrical stimulation of human skeletal muscle.
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人体骨骼肌间歇性电刺激期间疲劳的因素。
DOI：
10.1152/japplphysiol.01010.2001
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Binder-Macleod,StuartA
中科院分区：
文献类型：
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作者：
Russ,DavidW;Vandenborne,Krista;Binder-Macleod,StuartA
在电诱发的等长收缩期间，获得力的代谢成本大于维持力的代谢成本。因此，在这种刺激过程中产生的疲劳可能不仅仅是力-时间积分（FTI）的函数，如前所述。本研究的目的是评估通过不同频率（20、40或80 Hz）和持续时间（300、600或1，200 ms）的间歇等长电刺激在人体内侧腓肠肌中产生的疲劳，这些电刺激产生不同的峰值力和FTI。每例受试者（n= 10）共参加6次会议。在每次会议期间，受试者接受了一个前，后疲劳测试协议和不同的，150列车疲劳协议。每个疲劳方案仅使用单一频率和持续时间。不同方案产生的疲劳与疲劳方案的初始峰值力相关（r2= 0.74-0.85），但与初始或总FTI无关。所有测试的方案在响应低频刺激与高频刺激时产生了成比例的更大的力损伤（即，低频疲劳）。协议对低频疲劳没有影响，这表明所有协议在兴奋-收缩耦合中产生了相当程度的损伤。这些结果表明，对于短暂的刺激收缩，峰值力是比FTI更好的疲劳预测因子，可能是因为获得和维持力的不同代谢需求。
During an electrically elicited isometric contraction, the metabolic cost of attaining is greater than of maintaining force. Thus fatigue produced during such stimulation may not simply be a function of the force-time integral (FTI), as previously suggested. The goal of the present study was to evaluate fatigue produced in human medial gastrocnemius by intermittent, isometric electrical stimulation with trains of different frequencies (20, 40, or 80 Hz) and durations (300, 600, or 1,200 ms) that produced different peak forces and FTIs. Each subject (n= 10) participated in a total of six sessions. During each session, subjects received a pre- and postfatigue testing protocol and a different, 150-train fatiguing protocol. Each fatiguing protocol used only a single frequency and duration. The fatigue produced by the different protocols was correlated to the initial peak force of the fatiguing protocols (r2= 0.74–0.85) but not to the initial or total FTI. All of the protocols tested produced a proportionately greater impairment of force in response to low- vs. high-frequency stimulation (i.e., low-frequency fatigue). There was no effect of protocol on low-frequency fatigue, suggesting that all the protocols produced comparable levels of impairment in excitation-contraction coupling. These results suggest that, for brief stimulated contractions, peak force is a better predictor of fatigue than FTI, possibly because of the different metabolic demands of attaining and maintaining force.