Huffenus Anne-Fabienne, Forestier Nicolas
Laboratoire de Modélisation des Activités Sportives, UFR-CISM, Université de Savoie, Le Bourget du Lac, France.
Neurosci Lett. 2006 Jul 31;403(1-2):109-13. doi: 10.1016/j.neulet.2006.04.025. Epub 2006 May 16.
To investigate the capacity of the central nervous system to integrate and differentiate two different muscular fatigue states, the present study examines the changes on multi-joint movement organization following muscular fatigue of elbow extensor muscles (triceps brachii) induced by voluntary versus electrically induced contractions. Twenty right-handed male volunteers performed throws in the horizontal plane before and after two fatiguing procedures. First, success rate of throws was not affected by fatigue neither after voluntary contractions, nor after electrically induced contractions. Despite similar reductions of the maximal voluntary isometric force and the median frequency of the electromyographic signal following both fatiguing protocols, voluntary contractions induced greater changes in muscle activation, kinematics and kinetics during throws than electrically induced contractions. The changes observed following voluntary contractions are interpreted as a compensatory strategy involving a greater contribution of the wrist. In contrast, the greater activation of the triceps brachii could compensate the weakness of this muscle induced by fatigue without any modification of the initial multi-joint movement organization.
为了研究中枢神经系统整合和区分两种不同肌肉疲劳状态的能力，本研究考察了由自愿收缩与电刺激收缩诱发的肘伸肌（肱三头肌）肌肉疲劳后多关节运动组织的变化。20名右利手男性志愿者在两种疲劳程序前后进行了水平面上的投掷动作。首先，无论是在自愿收缩后还是电刺激收缩后，投掷成功率均未受疲劳影响。尽管两种疲劳方案后最大自愿等长肌力和肌电信号中位频率均有类似程度的降低，但与电刺激收缩相比，自愿收缩在投掷过程中引起了更大的肌肉激活、运动学和动力学变化。自愿收缩后观察到的变化被解释为一种涉及腕部更大贡献的代偿策略。相比之下，肱三头肌更大程度的激活可以补偿疲劳导致的该肌肉无力，而无需改变初始的多关节运动组织。
