[New electromyographic test in orthopedic diagnosis. Part I]

The new electromyographic test is based on fast Fourier transformation application for analysis of global electromyograms. Specifically designed Dynalog apparatus is described. Dynalog records EMG signal and transfers it to IBM-PC. One hundred thirty-eight global electromyograms were taken from 4 muscle groups (m.rectus femoris, m.deltoideus, mm. flexores antebrachii, mm. extensores antebrachii) in healthy individuals. Standard graphs of power distribution were obtained. Physiologically, at maximum voluntary contraction, power distribution spectrum of 4 muscles display characteristic, repeatable features. The frequency distribution range is 0-250 Hz. The records obtained show an ascending part (10-50 Hz), plateau (50-100 Hz) and mildly descending one at 150 Hz, subsequently to 250 Hz.