| The nature of motor unit correlation (motor unit synchrony) and motor unit common drive has been a topic of interest in the literature. There are contradictory results and confusion about motor unit correlation and motor unit common drive. A thorough study of this topic will help to explain the contradiction, resolve the confusion and will provide important insights about the motor control scheme.;The estimation methods for both motor unit correlation and motor unit common drive are reviewed and their limitations are discussed. A new method for estimating motor unit correlation is proposed based on the cross-correlation function. The experimental work suggests that motor unit correlation exists in normal human subjects at low force level contractions, but the degree of correlation is not significant for engineering applications. Both simulation and experimental work suggest that motor unit correlation and motor unit common drive are two different phenomena and have distinct physiological origins. |
