The importance of normalization in the interpretation of surface electromyography: A proof of principle
The importance of normalization in the interpretation of surface electromyography: A proof of principle
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DOI：
10.1016/s0161-4754(99)70032-1
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发表时间：
1999-09-01
影响因子：
1.3
通讯作者：
McGill, SM
中科院分区：
文献类型：
--
作者：
Lehman, GJ;McGill, SM
目的：探讨肌表电信号未经归一化处理可能导致的肌表电判读误差。设计：作为原则证明的案例研究。主要结果测量：在躯干弯曲期间，当肌电信号归一化（以最大自主收缩的百分比表示）时，一名受试者腹直肌上下部分之间的肌电振幅，以及当信号以原始的、未归一化的任意单位或直接从仪器读取的原始毫伏表示时的振幅。结果：对非归一化肌电图信号的解释表明，腹直肌上下段的神经激活存在很大差异。在这种情况下，下直肌的平均活动是上直肌的60.9%。这种解释是不正确的。当肌电信号被归一化后，上、下段之间的差异减小。当归一化时，下段的活动等于上段的活动。结论：由于肌电信号固有的可变性，临床对表面肌电信号的解释需要对信号进行归一化，以便进行生理解释和双侧肌肉之间、不同日期的同一肌肉之间以及不同受试者之间的比较。
Objective: To demonstrate the errors in surface electromyogram (EMG) interpretation that can be made when the EMG signal is not normalized.Design: A case study as a proof of principle.Main Outcome Measures: The EMG amplitude between the upper and lower portions of the rectus abdominis in one subject during a trunk curl when the EMG signal was normalized (expressed as a percentage of a maximum voluntary contraction) and the amplitude when the signal was expressed in raw, unnormalized arbitrary units or raw millivolts directly read from the instrumentation.Results: Interpretation of the unnormalized EMG signal suggests that a large difference in neural activation of the upper and lower sections of the rectus abdominis is occurring. In this condition the average activity in the lower rectus is 60.9% of that in the upper portion. This interpretation is incorrect. When the EMG signal is normalized, the differences between the upper and lower segments are reduced. When normalized, the lower segment activity is equal to that of the upper segment.Conclusions: Because of the inherent EMG signal variability, clinical interpretation of surface EMG signals requires normalization of the signal for physiologic interpretation and for comparison between bilateral muscles and between the same muscle on different days and between different subjects.