Transfer characteristic of the motor system of the hand obtained by electrical stimulation and its bearing on force tremor (author's transl)]

Pulse duration modulated signals were used to stimulate the extensor muscles of the hand. From this and from the isometric tension responses the frequency response of the human motor system was obtained. From the transfer characteristics of the components of the motor system which were taken from literature the frequency response of a closed-loop circuit model could be calculated. The theoretical frequency response was compared to the observed data. With increasing loop gain the model would show the characteristics of a filter tuned to the frequency of force-tremors.