1999 年 43 巻 5 号 p. 923-928
When the relationship between the electromyography (EMG) and the stomatognathic function was investigated, there are various analytical methods. However, there are no satisfactory methods for clinical use, so amplitude density function analysis of the surface EMG was applied in the stomatognathic region. The chief object of the analysis was to discriminate the spontaneous discharge that was to be seen in the muscle of the patient with pain in the stomatognathic area. Known waveforms (rectangular, triangle, and sine curve), normal EMG and spontaneous discharge of the EMG in a patient were studied.
By this analysis, the difference of the known waveform was represented by the shape of the density function. It was found that the distribution of the amplitude is directly related to the waveform. As for spontaneous discharge, the discrimination standard for the amplitude density function analysis was made by the half width of the distribution. Spontaneous discharge has a sharp peak in the amplitude density function comparing to the normal EMG. In comparison to the value of the half width divided by the distribution range, the spontaneous discharges (0.080±0.010) were separated from the EMG of the voluntary activity (0.13± 0.021).