Estimating reflex responses in large populations of motor units by decomposition of the high‐density surface electromyogram

摘要

Key points class="unordered" style="list-style-type:disc" id="tjp6769-list-0001">Reflex responses of single motor units have been used for the study of spinal circuitries but the methods employed are invasive and limited to the assessment of a relatively small number of motor units.We propose a new approach to investigate reflexes on individual motor units based on high‐density surface electromyography (HDsEMG) decomposition.The decomposition of HDsEMG has been previously validated in voluntary isometric contractions but never during reflex activities.The use of HDsEMG decomposition for reflex studies at the individual motor unit level, during constant force contractions, with excitatory and inhibitory stimuli, was validated here by the comparison of results with concurrently recorded intramuscular EMG signals.The validation results showed that HDsEMG decomposition allows an accurate quantification of reflex responses for a large number of individual motor units non‐invasively, for both excitatory and inhibitory stimuli.