A Spectral Analysis of Single Motor Unit Potentials from Human Extraocular Muscle

A spectral analysis of single motor unit potentials from the human medial rectus extraocular muscle is described. The analysis was performed by first averaging individual single motor unit potentials and then subjecting the average to Fourier analysis using a digital computer. The portion of the spectrum between 300 Hz and 2.8 kHz has definite bandpass characteristics with -3-dB points for the low-and high-frequency sides equal to 470 Hz and 1.4 kHz, respectively. The spectrum provides some insight into the characteristics of a filter that would provide an indication of the occurrence of single unit potentials in an interference electromyogram.