Abstract
An electrotherapy based on a computer analysis of results obtained by analytical electromyography has been put to laboratory trial. Twenty-seven normal subjects received comparative regimes of electrotherapy each of which occupied three continuous hours each day for seven weeks. A comparison of the effectiveness on increasing fatigue resistance to voluntary effort of the first dorsal interosseus in the right, dominant hand was made. All electrotherapies employed had a mean frequency of stimulation of approximately 10Hz. The difference between them was found in the changes of pattern of stimulation which was exactly based on the changing patterns of discharge of slow motor units in normal muscle as it was progressively fatigued. The ability of the electrotherapies to induce fatigue resistance of the muscle was directly related to the extent of fatigue of the motor unit from which the pattern of discharge, which formed the basis of the technique, had been extracted.
Electrotherapies with patterns randomized from naturally occurring patterns are shown to be without effect on increasing the fatigue resistance of normal muscle. The significance of the results from the points of view of rehabilitation and of signal analysis are discussed.