Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS 6612, Université de la Méediterranée, Faculté de Médecine de Marseille, 27 Boulevard Jean Moulin, 13005 Marseille, France.
Muscle Nerve. 2010 May;41(5):667-78. doi: 10.1002/mus.21572.
We have investigated the effects of stimulation frequency and pulse duration on fatigue and energy metabolism in rat gastrocnemius muscle during a single bout of neuromuscular electrical stimulation (NMES). Electrical pulses were delivered at 100 Hz (1-ms pulse duration) and 20 Hz (5-ms pulse duration) for the high (HF) and low (LF) frequency protocols, respectively. As a standardization procedure, the averaged stimulation intensity, the averaged total charge, the initial peak torque, the duty cycle, the contraction duration and the torque-time integral were similar in both protocols. Fatigue was assessed using two testing trains delivered at a frequency of 100 Hz and 20 Hz before and after each protocol. Metabolic changes were investigated in vivo using 31P-magnetic resonance spectroscopy (31P-MRS) and in vitro in freeze-clamped muscles. Both LF and HF NMES protocols induced the same decrease in testing trains and metabolic changes. We conclude that, under carefully controlled and comparable conditions, the use of low stimulation frequency and long pulse duration do not minimize the occurrence of muscle fatigue or affect the corresponding stimulation-induced metabolic changes so that this combination of stimulation parameters would not be adequate in the context of rehabilitation.
我们研究了在单次神经肌肉电刺激（NMES）期间，刺激频率和脉冲持续时间对大鼠比目鱼肌疲劳和能量代谢的影响。电脉冲分别以 100 Hz（1 ms 脉冲持续时间）和 20 Hz（5 ms 脉冲持续时间）的频率施加于高频（HF）和低频（LF）频率方案。作为标准化程序，在两个方案中，平均刺激强度、平均总电荷量、初始峰值扭矩、占空比、收缩持续时间和扭矩时间积分相似。使用频率为 100 Hz 和 20 Hz 的两个测试列车在每个方案前后进行疲劳评估。使用 31P 磁共振波谱（31P-MRS）在体内和在冷冻夹闭的肌肉中进行代谢变化研究。LF 和 HF NMES 方案均导致测试列车和代谢变化相同的减少。我们得出结论，在仔细控制和可比的条件下，使用低刺激频率和长脉冲持续时间并不能最小化肌肉疲劳的发生或影响相应的刺激诱导的代谢变化，因此这种刺激参数组合在康复背景下是不够的。
