Brerro-Saby Christelle, Delliaux Stéphane, Steinberg Jean Guillaume, Jammes Yves
UMR MD2, Physiologie et physiopathologie en conditions d'oxygénation extrêmes, Institut Jean Roche, Faculté de Médecine, Université de la Méditerranée, Bd. Pierre Dramard, 13916, Marseille, France.
Muscle Nerve. 2008 Nov;38(5):1481-1489. doi: 10.1002/mus.21117.
Fatigue-induced changes in the proprioceptive reflex loop were explored in humans by using the tonic electromyographic (EMG) response to vibration (TVR) and relating it to lactic acidosis (LA) and oxidative stress. TVR was measured in flexor digitorum superficialis before and after sustained or intermittent handgrip at maximal voluntary contraction (MVC). TVR variations were compared with the changes in EMG power spectrum preceding contractile fatigue, the Hoffman reflex (H-reflex), and plasma concentrations of LA and thiobarbituric acid reactive substances (TBARS). After both sustained and intermittent handgrips, TVR amplitude first declined then increased, independently from the changes in EMG power spectrum and H-reflex. TVR depression and facilitation were respectively concomitant with increases in LA and TBARS. The TVR depression was proportional to the increased LA level. The origin of TVR changes after muscle fatigue is questioned because the relationship between TVR depression and LA accumulation might be temporal, not causal, and changes in muscle stiffness were not explored.
通过使用对振动的强直性肌电图（EMG）反应（TVR）并将其与乳酸酸中毒（LA）和氧化应激相关联，研究了人类疲劳诱导的本体感觉反射环变化。在最大自主收缩（MVC）下持续或间歇性握力前后，测量指浅屈肌的TVR。将TVR变化与收缩性疲劳前的EMG功率谱变化、霍夫曼反射（H反射）以及LA和硫代巴比妥酸反应性物质（TBARS）的血浆浓度变化进行比较。在持续和间歇性握力后，TVR振幅先下降后增加，与EMG功率谱和H反射的变化无关。TVR抑制和易化分别与LA和TBARS的增加同时出现。TVR抑制与LA水平升高成正比。肌肉疲劳后TVR变化的起源受到质疑，因为TVR抑制与LA积累之间的关系可能是暂时的，而非因果关系，且未探讨肌肉僵硬度的变化。
