Abstract
【Introduction】It was too difficult to identify motor units (MUs) from measured surface electromyography during voluntary isovelocity elbow flexion. Because the waveforms of the MUs were changed with the distance from surface electrodes to muscle fibres of single MU changed. In this study, we considered how to decompose Surface Motor Unit Acton Potential (SMUAP) even in the case that the SMUAP was changing during voluntary isovelocity elbow flexion. 【Methods】The experiments were performed with one healthy subject who gave informed consent. The subject was instructed to flex the elbow joint smoothly at constant angular velocity (5 degree/s) against the applied load torque (10% MVC). We measured the SEMGs detected from biceps short head muscle during this period. The eight-channel surface electrode was used to measure the SEMG. The method of merge each 3.0 s MUAP trains was performed by analyzing the SEMG of 1.5s period overlapped two SEMGs. 【Results·Conclusions】The calculated MU's firing rates were in agreement with the generally accepted behavior of MUs firing rates. It was shown that the proposed method was useful for decomposing SMUAPs during voluntary isovelocity elbow flexion.
