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机构地区:[1]浙江大学理学院心理学系 [2]73021部队
出 处:《航天医学与医学工程》2006年第5期373-376,共4页Space Medicine & Medical Engineering
基 金:国家自然科学基金项目(30170447);中国-芬兰政府间科技合作项目(AM1021)
摘 要:目的研究最大随意收缩(MVC)诱发肌肉疲劳的表面肌电(sEMG)信号的变化规律。方法10名青年志愿者完成肱二头肌非疲劳性持重负荷试验和疲劳性最大随意收缩试验。采用线性和非线性信号处理方法,分析MVC下降到80%、70%、60%和50%时刻的sEMG信号特征变化并与非疲劳性活动时相同肌肉活动水平的sEMG信号进行比较。结果疲劳状态下的平均肌电值(AEMG)和确定性线段百分比(%DET)显著高于非疲劳状态,而平均功率谱(MPF)和Lempel-Ziv复杂度[C(n)]显著低于非疲劳状态。随着肌肉疲劳的发展,MPF和C(n)显著递减,而AEMG和%DET无显著变化。AEMG、MPF和C(n)在疲劳状态和负荷水平间存在显著的交互作用。结论最大随意收缩诱发肱二头肌疲劳过程中,sEMG信号的MPF和C(n)单调递减;疲劳和非疲劳状态的sEMG信号特征存在显著差异。Objective To investigate the effect of muscle fatigue on linear and nonlinear dynamics of sEMG from biceps brachii during maximal voluntary isometric contractions. Method Ten young volunteers subjects performed non-fatiguing isometric contractions with four load levels and fatiguing maximal voluntary isometric contractions. Linear and nonlinear analysis were used to examine the sEMG signals and the changes of sEMG signals when MVC decreased to levels of 80% MVC, 70% MVC, 60%MVC and 50% MVC compared with the signals of sEMG during non-fatiguing contrac- tions. Result Statistical analyses revealed that AEMG and %DET were significantly higher at fatigue states than those at non fatigue states, while MPF and C(n) were significantly lower than those at non fatigue states. With the development of muscle fatigue, MPF and % DET significantly decreased during maximal effort, while AEMG and %DET stayed stable. The interaction of load level and fatigue state for AEMG, MPF and C(n) were significant. Conclusion MPF and C(n) significantly decrease during maximal voluntary isometric contractions, sEMG dynamics between fatigue state and non-fatigue state is significantly different.
分 类 号:R857.11[医药卫生—航空、航天与航海医学] R741.044[医药卫生—临床医学]
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