Motor unit firing rates and synchronisation affect the fractal dimension of simulated surface electromyogram during isometric/isotonic contraction of vastus lateralis muscle. Issue 12 (December 2016)

• Record Type: Journal Article
• Authors: Mesin, Luca; Dardanello, Davide; Rainoldi, Alberto; Boccia, Gennaro
• Is Part Of: Medical engineering & physics. Volume 38:Issue 12(2016:Dec.)
• Page Start: 1530
• Page End: 1533
• Publication Date: 2016-12
• Subjects: Muscle fatigue -- Surface EMG -- Geometrical complexity -- Muscle fibre conduction velocity; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2016.09.022
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: A number nonlinear methods have been developed to track changes in motor units synchronisation from the EMG. Fractal dimension of EMG was affected by both motor units synchronisation and firing rate. Further work should aim to noninvasively discriminate between variations in motor units firing behaviour. Abstract: During fatiguing contractions, many adjustments in motor units behaviour occur: decrease in muscle fibre conduction velocity; increase in motor units synchronisation; modulation of motor units firing rate; increase in variability of motor units inter-spike interval. We simulated the influence of all these adjustments on synthetic EMG signals in isometric/isotonic conditions. The fractal dimension of the EMG signal was found mainly influenced by motor units firing behaviour, being affected by both firing rate and synchronisation level, and least affected by muscle fibre conduction velocity. None of the calculated EMG indices was able to discriminate between firing rate and motor units synchronisation.