EMG frequency spectral characteristics of inspiratory accessory muscles during the shoulder lifting motion in throwing athletes

Abstract

Background: Dysfunctions related to the shoulder joint are very common in throwing athletes, due to the overhead generated in repetitive movements with your arms above your head. In addition, in handball, the movements are of high intensity, which generates a large metabolic demand and high ventilatory demands. Studies show that highest work of the respiratory muscles, coupled with high mechanical requirement in the upper limbs, generates a dual requirement under the inspiratory muscles in these athletes, leading to limitations related to muscle fatigue. Objective: The objective of this study was to evaluate the EMG frequency spectral characteristics (fatigue index) to accessory muscles of inspiration, through the induction of shoulder elevation movement in handball athletes. Method/Design: The sample consisted of 25 male athletes with an average age of 20 years. Fatigue index was measured by surface electromyography (mean and median frequency -Hz), in which the volunteers performed isometric movement of elevation of the shoulders, and after collection, the data were processed off-line on Matlab R2014a software. For statistical analysis used the Shapiro-Wilk test to test the normality of the data, followed by the comparison of data through the Student t test for independent samples. Significant difference was considered for p value <0.05. Results: The results showed a significant difference between the mean and median frequency values for the sternocleidomastoid muscle right compared to the left sternocleidomastoid muscle. Conclusions: We conclude that during isometric movement of shoulder elevation, there was asymmetry in the frequency spectral characteristics of only one accessory muscles of inspiration, presenting asymmetry, and greater fatigue in the sternocleidomastoid muscle dominant side in relation to the non-dominant side.

Effect of Inspiratory Muscle Training on Performance of Handball Athletes

“…Following the above mentioned research, we believe that in handball, there is a high and double mechanical demand on inspiratory accessory muscles. This overload in throwing athletes has been also described by Hartz et al (2015) , and related to the high recruitment of the trunk and upper limb musculature during the sport-specific movements, high-contact situations and a high number of throws performed during a game ( Povoas et al, 2014 ). Consequently, improvement in inspiratory muscle conditioning may reflect a reduced mechanical demand and fatigue for inspiratory accessory muscles during intensive levels of handball game, which may be another factor associated with enhanced performance.…”

Asymmetrical fatiguing of the gluteus maximus muscles in the elite short-track female skaters

“…Asymmetry in muscle fatigability is certainly not limited to short track, however. Mastalerz et al [23] reported differences in myolectrical manifestations of fatigue between the muscles of the right and the left legs in runners, reaching from 12,5% to 26,5%, depending on the muscle Hartz et al measured the myolectrical manifestations of fatigue index through the induction of shoulder evation movement [24].…”

Asymmetrical fatiguing of the gluteus maximus muscles in the elite short-track female skaters.

“…Mastalerz et al reported differences in fatigue between the muscles of the right and the left legs in runners, reaching from 12,5 % to 26,5 %, depending on the muscle [24]. Hartz et al measured the fatigue index through the induction of shoulder evation movement [25].…”