Optimizing acquisition time in quantitative electromyography

Quantitative electromyography (QEMG) relies on a number of discharges of the same motor unit action potential (MUAP) from a train to create an averaged MUAP considered to be representative of a true potential. The train of potentials may be affected by changes in position of the electrode relative to contributing muscle fibers of the motor unit due to operator or subject movement. The effect of changes in electrode position, along with consideration for patient comfort, prompted this study to determine the shortest duration of recording time necessary for sufficient data acquisition for QEMG studies. We determined that 10 seconds of moderate muscle activity is the most reasonable acquisition duration to isolate up to 6 MUAPs at a given electrode site and minimize the effects of movement artifact in the signal.