Behm D G, St-Pierre D M
School of Physical Education and Athletics, Memorial University of Newfoundland, St. John's.
Can J Appl Physiol. 1997 Oct;22(5):468-78. doi: 10.1139/h97-030.
Since reported changes in muscle activation following fatigue could be affected by alterations in muscle contractile properties, the plantar flexors' activation-force relationship was investigated before and following an isometric, intermittent, submaximal fatigue protocol. Voluntary and evoked force and muscle activation was tested pre- and postfatigue with ischaemic and nonischaemic recovery. The muscle activation-force relationship of ischaemic and nonischaemic groups was best described by a second-order polynomial equation with similar y intercepts, slopes, and curvature of the slopes. A significantly increased muscle activation-force slope during recovery may be attributed to decreased muscle activation and not impaired muscle kinetics. The index of muscle activation immediately postfatigue was not significantly different between ischaemic and nonischaemic groups (88.5% vs. 92.7%). No significant difference in the estimate of muscle activation postfatigue with polynomials and interpolated twitch (IT) ratios (superimposed/potentiated doublets) suggested that IT ratios can be used as a general estimate of muscle inactivation following fatigue.
由于疲劳后报告的肌肉激活变化可能受肌肉收缩特性改变的影响，因此在进行等长、间歇性、次最大疲劳方案之前和之后，研究了跖屈肌的激活-力关系。在疲劳前后，采用缺血和非缺血恢复的方式测试了自主和诱发力量以及肌肉激活情况。缺血组和非缺血组的肌肉激活-力关系最好用二阶多项式方程来描述，其y轴截距、斜率和斜率曲率相似。恢复过程中肌肉激活-力斜率显著增加可能归因于肌肉激活减少，而非肌肉动力学受损。缺血组和非缺血组疲劳后即刻的肌肉激活指数无显著差异（88.5%对92.7%）。多项式和内插单收缩（IT）比率（叠加/增强双波）对疲劳后肌肉激活的估计无显著差异，这表明IT比率可作为疲劳后肌肉失活的一般估计指标。
