Activity of periscapular muscles and its correlation with external oblique during push-up: Does scapular dyskinesis change the electromyographic response?

Abstract

Scapular dyskinesis is the term used to describe changes in the positioning or movement of the scapula. Such dysfunction is associated with changes in the activation of the scapular muscles. However, the influence of the axial muscles on the scapular muscles activity of subjects with scapular dyskinesis is unknown. This study aimed to compare the electromyography (EMG) activity of periscapular muscles and its correlation with the external oblique muscle during the execution of push-up performed in different surfaces, in volunteers with and without scapular dyskinesis. Thirty-six men, divided in two groups (control and dyskinesis), performed push-up on stable and unstable surface. The EMG activity of serratus anterior (SA_5th and SA_7th fibers), upper (UT) and lower (LT) trapezius, external oblique (EO) was recorded during execution of each task condition. Statistical analyzes were performed using two way ANOVA repeated measures and Pearson correlation. It was observed effect of interaction between factors, being evidenced increased activity of UT, SA_7th and OE for the control group and decreased activity of SA_5th, SA_7th and EO for dyskinesis group during execution of push-up on unstable surface. In both groups positive correlations (r > 0.47) were observed between EMG activity of SA and EO. In the exercises tested, there seems to be an anatomical and functional relationship between the SA and EO muscles. The use of the unstable surface promotes increased neuromuscular demand, but the neuromuscular strategies appear to differ between groups.

Ajustes posturais dos músculos escapulares e globais como mecanismos de controle do movimento do ombro e da postura

“…According to results of the survey data, we have found that in most cases there is a change in muscle activity of the serratus anterior muscle, and abnormality in the muscle activation time or activation intensity (Araújo et al 2017;Bohlooli et al, 2015;Helgadottir et al, 2011;Hio Teng Leong et al, 2017;Oliveira et al, 2012;Padke and Ludewig, 2013;, this result is in agreement with our hypothesis. In contrast, some studies show no change between patients and controls (Ayatollahia et al, 2016;Bandholm et al, 2006;Castelein et al 2016;Cools et al, 2004;Faria et al, 2008;Larsen et al, 2013;Lopes et al, 2015;Moraes et al, 2008;Roy et al, 2008;Santos et al, 2015), which means that there is still doubt about the role of the serratus anterior in these cases.…”

“…The results demonstrate that from the 25 articles selected (Table 3, Table 4 and Table 5), in 10 an abnormal muscle activation intensity of the SA was found (Araújo et al 2017;Helgadottir et al 2011;Oliveira et al 2012) (Table 3) and 8 has shown equal muscle activation intensity between patients and controls (Ayatollahia et al, 2016;Bandholm et al 2006;Castelein et al, 2016;Cools et al 2004;Faria et al 2008;Lopes et al 2015;Larsen et al 2013;Roy et al 2008) (Table 4). Among the results, 8 studies found a lower muscle activity of SA during tasks of upper limb between patients and controls (Araújo et al 2017;,…”

Muscle Activity Ratios of Scapular Stabilizers During Closed Kinetic Chain Exercises in Healthy Shoulders: A Systematic Review

“…Male participants were predominant (66%). Fourteen studies 15,21,22,[24][25][26][27][28][29][30][31][32][33][34] included only males and one study 14 included only females. Furthermore, 3 studies 32,35,36 specifically included athletes as participants, and one study 21 included participants who were considered as advanced in resistance training.…”

“…All included participants completed the study protocols with no dropout. Eight of the included studies 15,22,24,26,27,31,35,37 performed a physical examination by a medical professional before testing, and only 2 studies 25,28 controlled for the presence of scapular dyskinesis. The absence of these examinations may reduce internal validity.…”

“…All but 12 16,17,20,25,28,29,33,35,36,[39][40][41] of the included studies performed exercises using standardized speed and phase durations. All included studies performed appropriate normalization of raw EMG data.…”