Electromyogram and mechanomyogram changes in fresh and fatigued muscle during sustained contraction in men
Electromyogram and mechanomyogram changes in fresh and fatigued muscle during sustained contraction in men
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男性持续收缩过程中新鲜肌肉和疲劳肌肉的肌电图和肌力图变化
DOI：
10.1007/s004210050451
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
A. Veicsteinas
中科院分区：
文献类型：
--
作者：
F. Esposito;C. Orizio;A. Veicsteinas
摘要表面肌电图（EMG）和机械肌电图（MMG）对运动单位（MU）的电活动和机械活动进行了总结。肌肉疲劳影响活动MU的电和机械特性。本研究的目的是评估疲劳引起的变化的电气和机械性能的MU后，一个短暂的恢复期，使用力，表面肌电图和MMG的分析。在7名受试者的EMG和MMG记录从肱二头肌肌肉在持续等长努力在80%的最大随意收缩（MVC），之前（测试1）和10分钟后（测试2）疲劳运动。从信号的时域和频域分析，计算功率谱的均方根（rms）和平均频率（f ′）。结果表明，新鲜肌肉和疲劳肌肉的平均MVC分别为412（SEM 90）N和304（SEM 85）N;在测试1和2期间，平均EMG rms从0.403增加到0.404（SEM 85）N。（SEM 0.07）mV至0.566（SEM 0.09）mV和0.476（SEM 0.07）mV至0.63（SEM 0.09）mV;在测试1期间，平均MMG rms从9.4（SEM 0.8）mV至5.7（SEM 0.9）mV;相反，在测试2期间，在整个收缩过程中观察到持续较低的值;在测试1和2期间，EMG f ′分别从122（SEM 7）Hz下降到74（SEM 7）Hz和从106（SEM 8）Hz下降到60（SEM 7）Hz;在试验1期间，MMG f ′在前6秒内从19.3增加到19.3（SEM 1.4）Hz至23.9（SEM 2.9）Hz，降至13.9（SEM 1.3）Hz;相反，在测试2期间，MMG f ′从18.7（SEM 1）Hz连续下降到12.4（SEM 0.8）Hz。疲劳运动后较低的MVC和EMG参数的变化证实，疲劳运动后10分钟，MU的机械和电活动发生了变化。此外，MMG结果表明，经过10分钟的恢复，一些高度疲劳的MU可能无法再招募。
Abstract In surface electromyogram (EMG) and mechanomyogram (MMG) the electrical and mechanical activities of recruited motor units (MU) are summated. Muscle fatigue influences the electrical and mechanical properties of the active MU. The aim of this study was to evaluate fatigue-induced changes in the electrical and mechanical properties of MU after a short recovery period, using an analysis of force, surface EMG and MMG. In seven subjects the EMG and MMG were recorded from the biceps brachii muscle during sustained isometric effort at 80% of the maximal voluntary contraction (MVC), before (test 1) and 10 min after (test 2) a fatiguing exercise. From the time and frequency domain analysis of the signals, the root mean square (rms) and the mean frequency (f¯) of the power spectrum were calculated. The results were that the mean MVC was 412 (SEM 90) N and 304 (SEM 85) N in fresh and fatigued muscle, respectively; during tests 1 and 2 the mean EMG rms increased from 0.403 (SEM 0.07) mV to 0.566 (SEM 0.09) mV and from 0.476 (SEM 0.07) mV to 0.63 (SEM 0.09) mV, respectively; during test 1 the mean MMG rms decreased from 9.4 (SEM 0.8) mV to 5.7 (SEM 0.9) mV; in contrast, during test 2 constantly lower values were observed throughout contraction; during tests 1 and 2 the EMG f¯ declined from 122 (SEM 7) Hz to 74 (SEM 7) Hz and from 106 (SEM 8) Hz to 60 (SEM 7) Hz, respectively; during test 1 the MMG f¯ increased in the first 6 s from 19.3 (SEM 1.4) Hz to 23.9 (SEM 2.9) Hz, falling to 13.9 (SEM 1.3) Hz at the end of contraction; in contrast, during test 2 the MMG f¯ declined continuously from 18.7 (SEM 1) Hz to 12.4 (SEM 0.8) Hz. The lower MVC after the fatiguing exercise and the changes in the EMG parameters confirmed that 10 min after the fatiguing exercise, the mechanical and electrical activities of MU were altered. In addition, the MMG results suggested that after a 10-min recovery, some highly fatigable MU might not be recruitable.
刺激模式对成年猫单个运动单位疲劳的影响。
DOI：
10.1113/jphysiol.1992.sp019076
发表时间：
1992
期刊：
The Journal of physiology
影响因子：
--
作者：
Bevan,L;Laouris,Y;Reinking,RM;Stuart,DG
通讯作者：
Stuart,DG