Variability of Superposition of Action Potentials, Theoretical Model

Linearity of values of rectified and integrated EMG signals with frequency of incidence of action potentials in muscle fibers and the effect of moving average window width on the range of values of integrated signals was tested on theoretical model. Our simulations of 4 overlapping single units multipotential signal demonstrated that integrated EMG signals are only approximately linearly proportional to the frequency of action potentials in the superposition multipotential. The width of moving average window influences the range (dispersion) of integrated values (their accuracy). Quality of EMG recordings, the frequency (the number) of action potentials as well as the width of moving average window increase the accuracy of the determination of integrated EMG signal.