Petrofsky J, Laymon M, Prowse M, Gunda S, Batt J
Department of Physical Therapy, Loma Linda University, CA 92350, USA.
J Med Eng Technol. 2009;33(2):170-81. doi: 10.1080/03091900802054580.
Electrical stimulation is a commonly used modality for both athletic training and physical therapy. However, there are limited objective data available to determine the waveform which provides the maximum muscle strength as well as minimizing pain. In the present investigation, two groups of subjects were examined. Group 1 was composed of six males and four females and group 2 was composed of three male and three female subjects. The first series of experiments investigated muscle strength with stimulation at currents of 20, 40 and 60 milliamps using sine, square, Russian and interferential waveforms evaluating strength production and pain as outcomes. The second phase of experiments compared the effect of the different waveforms on current dispersion in surface versus deep muscle electrodes with these same waveforms. The results of the experiments showed that sine wave stimulation produced significantly greater muscle strength and significantly less pain than square wave, Russian or interferential stimulation at that same current. The most painful stimulation was square wave. Strength production was greatest with sine wave and least with Russian and interferential. An explanation of these findings may be the filtering effect of the fat layer separating skin from muscle. The highly conductive muscle and skin dermal layers would form the plates of a capacitor separated by the subcutaneous fat layer providing an RC filter. This filtering effect, while allowing sine wave stimulation to pass to the muscle, reduced power transfer in square wave, Russian and interferential stimulation is observed.
电刺激是运动训练和物理治疗中常用的一种方式。然而，目前可用于确定能提供最大肌肉力量并使疼痛最小化的波形的客观数据有限。在本研究中，对两组受试者进行了检查。第一组由6名男性和4名女性组成，第二组由3名男性和3名女性受试者组成。第一系列实验使用正弦波、方波、俄罗斯波和干扰波，在20、40和60毫安电流下进行刺激，以评估力量产生和疼痛情况，从而研究肌肉力量。实验的第二阶段比较了不同波形对表面肌肉电极和深部肌肉电极中电流扩散的影响，波形与上述相同。实验结果表明，在相同电流下，正弦波刺激产生的肌肉力量明显更大，疼痛明显更小。最疼痛的刺激是方波。正弦波产生的力量最大，俄罗斯波和干扰波产生的力量最小。这些发现的一种解释可能是将皮肤与肌肉分开的脂肪层的滤波作用。高导电性的肌肉和皮肤真皮层会形成一个由皮下脂肪层隔开的电容器极板，提供一个RC滤波器。这种滤波作用在允许正弦波刺激传递到肌肉的同时，减少了方波、俄罗斯波和干扰波刺激中的功率传递。
