Enhanced Estimation of Motor Unit Number and Distribution Using Linear Least Squares Modeling

MUNE methods estimate the typical motor unit (MU). The typical MU amplitude is divided into the compound muscle action potential (CMAP) amplitude to obtain the MUNE. A novel method is proposed in which the CMAP is modeled as a linear least squares (LLS) fit of the MU waveforms. The sum of the coefficients in the model is the motor unit number estimate. Each coefficient represents the count of the different MU estimates. The MU waveforms are clustered into groups with similar morphology and a representative waveform is calculated for each cluster. These representative waveforms are used in the LLS model