Department of Kinesiology and Health Education, University of Texas at Austin, Bellmont 222, 1 University Station, D3700, Austin, TX 78712, USA.
Eur J Appl Physiol. 2010 Dec;110(6):1235-42. doi: 10.1007/s00421-010-1625-1. Epub 2010 Aug 25.
Muscle force potentiation affects force output during electrical stimulation. Few studies have examined stimulation train parameters that influence potentiation such as pulse number, stimulation frequency, train duration, and force-time integral and peak force produced during the train. Pulse-matched trains (100 pulses) at 7.5, 15, 25, 30, 50, and 100 Hz, and trains of varying pulse number (50, 100, and 200 pulses) at 30 and 50 Hz were delivered to the ulnar nerve of 10 (5 male, 5 female; 23.4 ± 0.9 years), healthy individuals in random order. Single twitches of the adductor pollicis muscle were elicited before and after each train with a rest interval of at least 5 min between each train. No differences in potentiation occurred across the pulse-matched trains at frequencies of 15-50 Hz (38.9 ± 5.4-44.6 ± 5.5%). Twitch force potentiation following the highest (100 Hz) and lowest (7.5 Hz) frequency trains were not significantly different and were lower than the other 100 pulse-matched trains. As pulse number increased, potentiation increased for both the 30 and 50-Hz trains. There was a significant positive correlation between force potentiation and force-time integral produced by the stimulation train, r = 0.70. The results indicate that potentiation magnitude is dependent on the force-time integral produced during the test train and the number of pulses delivered, independent of stimulation frequency.
肌肉力量增强会影响电刺激时的力量输出。很少有研究探讨影响增强的刺激训练参数，例如脉冲数、刺激频率、训练持续时间以及训练过程中产生的力时间积分和峰值力。以 7.5、15、25、30、50 和 100 Hz 的频率，分别施加 100 个脉冲的脉冲匹配训练，以及以 30 和 50 Hz 的频率施加不同脉冲数（50、100 和 200 个脉冲）的训练，随机顺序施加于 10 名（5 名男性，5 名女性；23.4±0.9 岁）健康个体的尺神经。在每次训练前后，用至少 5 分钟的休息间隔引出拇内收肌的单次抽搐。在 15-50 Hz 的频率范围内，脉冲匹配训练之间的增强没有差异（38.9±5.4-44.6±5.5%）。最高（100 Hz）和最低（7.5 Hz）频率训练后的抽搐力增强没有显著差异，且低于其他 100 个脉冲匹配训练。随着脉冲数的增加，30 和 50 Hz 训练的增强也随之增加。刺激训练产生的力增强与力时间积分之间存在显著正相关，r=0.70。结果表明，增强幅度取决于测试训练过程中产生的力时间积分和所施加的脉冲数，而与刺激频率无关。
