Effect of mental fatigue on induced tremor in human knee extensors
Effect of mental fatigue on induced tremor in human knee extensors
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DOI：
10.1016/j.jelekin.2014.02.003
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发表时间：
2014-06-01
影响因子：
2.5
通讯作者：
De Vito, Giuseppe
中科院分区：
文献类型：
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作者：
Budini, Francesco;Lowery, Madeleine;De Vito, Giuseppe
本研究探讨了心理疲劳对低频(3-6赫兹)和高频(8-12赫兹)机械性震颤的影响。在12名健康(29+/-3.7岁)受试者中，20名S在精神疲劳任务100分钟前后30%的最大自主收缩(MVC)时，用两个不同刚度的弹簧诱发了两种不同的震颤频率。仅在诱发高频持续30%的MVC收缩时，精神疲劳导致MVC下降6.9%，激动肌EMG幅度下降9.4%。在心理疲劳任务后，8-12赫兹诱发震颤时，力信号的变异系数和标准差分别降低了31.7%和35.2%，而3-6赫兹诱发震颤时，差异不显著。同样，仅在8-12赫兹范围内，力信号功率谱的最大值和峰下面积分别减少了55.5%和53.1%。综上所述，心理疲劳减少了机械诱发的8-12赫兹震颤，而对诱发的3-6赫兹震颤没有影响。我们认为，这种减少可能归因于激动肌的激活减少。(C)2014爱思唯尔有限公司。保留所有权利。
In this study, the effects of mental fatigue on mechanically induced tremor at both a low (3-6 Hz) and high (8-12 Hz) frequency were investigated. The two distinct tremor frequencies were evoked using two springs of different stiffness, during 20 s sustained contractions of the knee extensor muscles at 30% maximum voluntary contraction (MVC) before and after 100 min of a mental fatigue task, in 12 healthy (29 +/- 3.7 years) participants. Mental fatigue resulted in a 6.9% decrease in MVC and in a 9.4% decrease in the amplitude of the agonist muscle EMG during sustained 30% MVC contractions in the induced high frequency only. Following the mental fatigue task, the coefficient of variation and standard deviation of the force signal decreased at 8-12 Hz induced tremor by 31.7% and 35.2% respectively, but not at 3-6 Hz induced tremor. Similarly, the maximum value and area underneath the peak in the power spectrum of the force signal decreased by 55.5% and 53.1% respectively in the 8-12 Hz range only. In conclusion, mental fatigue decreased mechanically induced 8-12 Hz tremor and had no effect on induced 3-6 Hz tremor. We suggest that the reduction could be attributed to the decreased activation of the agonist muscles. (C) 2014 Elsevier Ltd. All rights reserved.