Institute of Movement Sciences and Sports Medicine, University of Geneva, Geneva, Switzerland.
Eur J Appl Physiol. 2014 Jan;114(1):205-15. doi: 10.1007/s00421-013-2760-2. Epub 2013 Nov 7.
The present study was designed to determine the stimulation intensity necessary for an adequate assessment of central and peripheral components of neuromuscular fatigue of the knee extensors.
Three different stimulation intensities (100, 120 and 150% of the lowest intensity evoking a plateau in M-waves and twitch amplitudes, optimal stimulation intensity, OSI) were used to assess voluntary activation level (VAL) as well as M-wave, twitch and doublet amplitudes before, during and after an incremental isometric exercise performed by 14 (8 men) healthy and physically active volunteers. A visual analog scale was used to evaluate the associated discomfort.
There was no difference (p > 0.05) in VAL between the three intensities before and after exercise. However, we found that stimulating at 100% OSI may overestimate the extent of peripheral fatigue during exercise, whereas 150% OSI stimulations led to greater discomfort associated with doublet stimulations as well as to an increased antagonist co-activation compared to 100% OSI.
We recommend using 120% OSI, as it constitutes a good trade-off between discomfort and reliable measurements.
本研究旨在确定评估膝关节伸肌神经肌肉疲劳的中枢和外周成分所需的刺激强度。
使用三种不同的刺激强度（100%、120%和 150%能引起 M 波和单收缩波幅平台的最低强度，即最佳刺激强度，OSI）来评估自愿激活水平（VAL）以及在 14 名（8 名男性）健康和活跃的志愿者进行递增等长运动前后的 M 波、单收缩和双脉冲波幅。使用视觉模拟量表评估相关不适。
运动前后三种刺激强度之间的 VAL 无差异（p > 0.05）。然而，我们发现，在运动过程中，100%OSI 刺激可能高估外周疲劳的程度，而 150%OSI 刺激与双脉冲刺激相关的不适更大，并导致拮抗肌共同激活增加，与 100%OSI 相比。
我们建议使用 120%OSI，因为它在不适和可靠测量之间取得了良好的平衡。
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