Miller C, Thépaut-Mathieu C
Laboratoire de Physiologie et Biomécanique Institut National du Sport et de l'Education Physique, Paris, France.
Int J Sports Med. 1993 Jan;14(1):20-8. doi: 10.1055/s-2007-1021140.
The overload imposed on the neuromuscular system under Electrostimulation (ES) can be expressed by applied current intensity or by Electrically Evoked Torque (EET). The aim of this study was to discern which of these two parameters is the one which is determinant for the efficacy of training by ES. Test and training involved isometric contraction of the flexion maintained at a joint angle of 25 degrees (0 degree = extension). The 16 trained subjects received 15 sessions of 25 electrically evoked contractions, using a monophasic rectangular waveform current at a frequency of 2500 Hz modulated at 90 Hz. Each stimulation lasted for 5 sec at the maximal tolerable current. Contrary to the control group (n = 16), the trained group significantly increased their MVIC (15.6%). The individual strength gains ranged from -5% to 49%. No correlation was found between current level and strength modifications. A direct relation was established between the EET and the strength gains (a minimum threshold of EET must be reached during at least 8 sessions to induce strength increases). The "overload principle", previously described for voluntary contraction strengthening, seems to be suitable for electrical stimulation and concerns the EET shown on the ergometer as the effect of the contraction of agonist and antagonist muscles.
电刺激（ES）对神经肌肉系统施加的过载可以通过施加的电流强度或电诱发扭矩（EET）来表示。本研究的目的是确定这两个参数中哪一个是决定ES训练效果的因素。测试和训练包括在25度关节角度（0度=伸展）保持等长收缩。16名训练对象接受了15次训练，每次训练有25次电诱发收缩，使用频率为2500Hz、调制频率为90Hz的单相矩形波电流。每次刺激在最大耐受电流下持续5秒。与对照组（n = 16）相反，训练组的最大等长收缩力量（MVIC）显著增加（15.6%）。个体力量增加幅度在-5%至49%之间。未发现电流水平与力量变化之间存在相关性。EET与力量增加之间建立了直接关系（至少在8次训练中必须达到EET的最低阈值才能诱导力量增加）。先前描述的用于增强自主收缩的“过载原则”似乎适用于电刺激，并且涉及测力计上显示的EET，它是主动肌和拮抗肌收缩的结果。
