Muscle fatigue during concentric and eccentric contractions
Muscle fatigue during concentric and eccentric contractions
复制标题
向心和离心收缩时肌肉疲劳
作者：
B. Pasquet;A. Carpentier;J. Duchateau;K. Hainaut
我们通过在同心(CON)和偏心(ECC)条件下进行测试，比较了中央和外周突起对踝背屈肌引起的肌肉疲劳的贡献。每次疲劳测试包括5组30次最大自主收缩，以50°的恒速/S测试30°的踝关节活动范围。在疲劳试验过程中记录背屈肌力矩和胫前肌的表面肌电信号。记录实验前、实验中、实验后的复合肌肉动作电位(M波)、对单个和成对电刺激的收缩特性，以及内插法和激活后电位法(PAP)。与ECC收缩相比，CON收缩导致更大的力量损失(−31.6%比−23.8%)和肌电活动下降(−26.4%比−17.5%)。这种差异在前四组收缩期间最为明显，但在最后一组收缩期间有所缩小。测试没有改变激活，因为在两个疲劳测试中，内插抽动反应和自愿肌电与M波幅度的比率都没有改变。虽然两种测试的M波幅度没有显著差异，但发现CON的抽动参数和PAP的变化大于ECC收缩。结果表明，在CON收缩过程中观察到的收缩特性的更大变化表明，细胞内钙离子控制的兴奋-收缩(E-C)耦合过程受到的影响比ECC收缩时大得多，这可能与更高的能量需求有关。©2000 John Wiley&Sons，Inc.肌肉神经23：1727-1735,2000
We compared the contribution of central and peripheral processes to muscle fatigue induced in the ankle dorsiflexor muscles by tests performed during concentric (CON) and eccentric (ECC) conditions. Each fatigue test consisted of five sets of 30 maximum voluntary contractions at a constant speed of 50°/s for a 30° range of motion of the ankle joint. The torque produced by the dorsiflexors and the surface electromyogram (EMG) of the tibialis anterior muscle were recorded during the fatigue tests. Before, during, and after the tests, the compound muscle action potential (M wave) and the contractile properties in response to single and paired electrical stimuli, as well as the interpolated‐twitch method and postactivation potentiation (PAP), were recorded during isometric conditions. Compared with ECC contractions, the CON ones resulted in a greater (P < 0.05) loss of force (−31.6% vs. −23.8%) and a decrease in EMG activity (−26.4% vs. −17.5%). This difference was most pronounced during the first four sets of contractions, but was reduced during the last set. Activation was not altered by the tests because neither the interpolated‐twitch response nor the ratio of the voluntary EMG to the amplitude of the M wave was changed in the two fatigue tests. Although there was no significant difference in M‐wave amplitude between the two tests, changes in the twitch parameters and in the PAP were found to be greater in the CON than ECC contractions. It is concluded that the greater alterations in the contractile properties observed during the CON contractions indicate that intracellular Ca2+‐controlled excitation–contraction (E–C) coupling processes, possibly associated with a higher energy requirement, are affected to a much greater degree than during ECC contractions. © 2000 John Wiley & Sons, Inc. Muscle Nerve 23: 1727–1735, 2000
影响因子：
5.5
作者：
FUGLEVAND, AJ;ZACKOWSKI, KM;ENOKA, RM
通讯作者：
ENOKA, RM
影响因子：
4.1
作者：
J. Fridén;J. Fridén;R. Lieber;R. Lieber
通讯作者：
J. Fridén;J. Fridén;R. Lieber;R. Lieber