Surface electromyographic evaluation of the neuromuscular activation of the inspiratory muscles during progressively increased inspiratory flow under inspiratory-resistive loading

Abstract

This study aimed to evaluate neuromuscular activation in the scalene and sternocleidomastoid muscles using surface electromyography (EMG) during progressively increased inspiratory flow, produced by increasing the respiratory rate under inspiratory-resistive loading using a mask ventilator. Moreover, we attempted to identify the EMG inflection point (EMG) on the graph, at which the root mean square (RMS) of the EMG signal values of the inspiratory muscles against the inspiratory flow velocity acceleration abruptly increases, similarly to the EMG anaerobic threshold (EMG) reported during incremental-resistive loading in other skeletal muscles. We measured neuromuscular activation of healthy male subjects and found that the inspiratory flow velocity increased by approximately 1.6-fold. We successfully observed an increase in RMS that corresponded to inspiratory flow acceleration with ρ ≥ 0.7 (Spearman's rank correlation) in 17 of 27 subjects who completed the experimental protocol. To identify EMG, we analyzed the fitting to either a straight or non-straight line related to the increasing inspiratory flow and RMS using piecewise linear spline functions. As a result, EMG was identified in the scalene and sternocleidomastoid muscles of 17 subjects. We believe that the identification of EMG in this study infers the existence of EMG in inspiratory muscles. Application of surface EMG, followed by identification of EMG, for evaluating the neuromuscular activation of respiratory muscles may be allowed to estimate the signs of the respiratory failure, including labored respiration, objectively and non-invasively accompanied using accessory muscles in clinical respiratory care.

Effects of Proprioception and Visual Focus of Attention on Surface Electromyography Proportional Control

“…Figure 6 plots the EEG-sEMG coherence waveforms for three factors in various bands of the C3 and biceps channels in vertical motion. It can be observed that the frequency bands in which the coefficient values increase significantly are concentrated at [16][17][18][19][20][21][22][23][24][25] Hz. It has coherence in the local frequency band above 25 Hz.…”

“…Root mean square (RMS) is a relatively common sEMG signal time-domain feature, and to a certain extent, reflects the contribution of each muscle group in the process of motion. RMS is defined as [18]:…”

Changes in power of surface electromyogram during breath-holding

“…Conflict of interest: None declared. The column P SC rest depicts the rest and P SC bump the P AV value during the "bump" period in the sternocleidomastoid (SCM) region, while similarly P D rest is the rest and P D bump is the "bump" value of P AV in the diaphragm (DIA) region, according to the labeling by the Japanese group [31]; the P AV influx in percentages for the SCM and the DIA regions are denoted by ΔP SC and ΔP D , respectively; the maximum influx for each volunteer is given in the following column, depicted as ΔP MAX ; T RLX is the relaxation period in milliseconds after the P AV was returned to the values equal to the initial state; the raw AVG shows the simple average value for all columns, while SD shows the standard deviation for the last four columns on the right; the most important values in the first (No. ), sixth (ΔP SC ) and seventh (ΔP D ) columns are in bold; while Δ MIN shows the minimal increase, Δ MAX shows the maximum increase for the last two columns on the right.…”