Fatigue considerations of muscle contractile force during high-frequency stimulation.

In a model for control of muscle force, wherein an induced background tetanus is attenuated by concurrent indirect stimulation at frequencies in the 0.6- to 10-kHz range, evaluation was made for effects on muscle fatigue of differing rates of the tetanic and high-frequency stimuli. Relatively little fatigue, and yet nearly the complete range of attenuation, were favored by lower frequencies of both these stimuli, e.g., tetanic stimulation at 50 Hz and a blocking frequency of 600 Hz.