Hodges P W, Bui B H
Department of Physiotherapy, University of Queensland, Brisbane, Australia.
Electroencephalogr Clin Neurophysiol. 1996 Dec;101(6):511-9. doi: 10.1016/s0013-4694(96)95190-5.
Little consensus exists in the literature regarding methods for determination of the onset of electromyographic (EMG) activity. The aim of this study was to compare the relative accuracy of a range of computer-based techniques with respect to EMG onset determined visually by an experienced examiner. Twenty-seven methods were compared which varied in terms of EMG processing (low pass filtering at 10, 50 and 500 Hz), threshold value (1, 2 and 3 SD beyond mean of baseline activity) and the number of samples for which the mean must exceed the defined threshold (20, 50 and 100 ms). Three hundred randomly selected trials of a postural task were evaluated using each technique. The visual determination of EMG onset was found to be highly repeatable between days. Linear regression equations were calculated for the values selected by each computer method which indicated that the onset values selected by the majority of the parameter combinations deviated significantly from the visually derived onset values. Several methods accurately selected the time of onset of EMG activity and are recommended for future use.
关于确定肌电图（EMG）活动起始的方法，文献中几乎没有达成共识。本研究的目的是比较一系列基于计算机的技术相对于由经验丰富的检查者通过视觉确定的EMG起始的相对准确性。比较了27种方法，这些方法在EMG处理（10、50和500Hz的低通滤波）、阈值（超过基线活动平均值1、2和3个标准差）以及平均值必须超过定义阈值的样本数量（20、50和100ms）方面有所不同。使用每种技术对300次随机选择的姿势任务试验进行了评估。发现EMG起始的视觉确定在不同日期之间具有高度可重复性。为每种计算机方法选择的值计算了线性回归方程，这表明大多数参数组合选择的起始值与视觉得出的起始值有显著偏差。有几种方法准确地选择了EMG活动的起始时间，建议今后使用。
