Determination of the motor unit behavior of lumbar erector spinae muscles through surface EMG decomposition technology in healthy female subjects

Abstract

Introduction: The aims of this study were to determine the motor unit behavior of the erector spinae muscles and to assess whether differences exist between the dominant/non-dominant sides of the back muscles.
Methods: Nine healthy women, aged 21.7 years (±0.7), performed a back extension test. Surface electromyographic decomposition data were collected from both sides of the erector spinae and decomposed into individual motor unit action potential trains. The mean firing rate for each motor unit was calculated, and a regression analysis was performed against the corresponding recruitment thresholds.
Results: The mean firing rate ranged from 15.9 to 23.9 pulses per second (pps) and 15.8 to 20.6 pps on the dominant and non-dominant sides, respectively. However, the early motor unit potential s of the non-dominant lumbar erector spinae muscles were recruited at a lower firing rate.
Conclusions: This technique may further our understanding of individuals with back pain and other underlying neuromuscular diseases.