The reliability of EMG muscle scanning.

The reliability of a surface EMG scanning procedure was investigated for the right and left aspects of ten muscle sites using a large clinical sample of 102 chronic patients. Two neutral postures (sitting/standing) were systematically studied on three occasions approximately one hour apart on the same day. The multivariate analysis of RMS microvolts indicated no significant effects for Age, Gender, Muscle Site, Aspect, or Period. The range of the Pearson correlations was 0.41 to 0.94 when all muscle sites, aspects, postures, and periods were considered. The median correlation was found to be 0.64. The pattern of reliability was seen to be slightly higher in the lower back while standing. The results indicate that with adequate attention to skin preparation, EMG sensors held in place by hand with a light pressure produced reliable results.