Comportamento da atividade elétrica muscular e desempenho de asmáticos durante o Incremental Shuttle Walking Test e Teste Glittre-AVD

Abstract

Asthmatic individuals exhibit impairment both respiratory muscle function, due to changes in ventilatory mechanics, and peripheral, caused by metabolic alterations with reduction of oxidative capacity. Such conditions result in increased dyspnea and fatigue. How these muscles are activated during daily activities in this population is undetermined. Thus, the goal of this study was to analyze the behavior of the electrical activity of respiratory and peripheral muscles and performance in exercise tests: Incremental Shuttle Walking Test (ISWT) and Glitter-ADL test in asthmatic subjects comparing with non asthmatic subjects. Participated patients with clinical diagnosis of asthma, of both gender, aged between 20 and 50 years, controlled disease, body mass index (BMI) below 30 kg / m², non smokers and non asthmatic subjects matched by age, sex and BMI. After initial assessment, all participants were submitted to two exercise tests: ISWT and the Glitter-ADL test. During the tests, were evaluated the sternocleidomastoid (ECOM), scalene (ESC), rectus abdominis (RA) and rectus femoris (RF) muscles for the ISWT and ESC, RA, RF and the middle deltoid (DM) muscle for the Glitter-ADL test, through surface electromyography (EMGs). The statistical analysis was done by the statistical program GraphPad Prism version 6.0, for p <0.05. The Shapiro-Wilk test was used for the normality of the studied variables and Mann-Whitney for intergroup analysis of cardiovascular, respiratory and Borg variables (dyspnea and fatigue). For intergroup analysis of the electrical activity of the muscles studied it was used the unpaired T test for the ISWT and Mann-Whitney test for the Glitter-ADL test. Sixteen asthmatic patients composed the Asthma Group (GA) and ten non-asthatic subjects Control Group (CG). The GA vs GC sample showed: age: 35.31 ± 11.31 vs 34.70 ± 15.61, IMC kg / m2: 24.49 ± 4.15 vs 22.34 ± 1.797, FEV1%: 78.74 ± 17.41 vs 90.84 ± 7.74 (p <0.01), FEV 1 / FVC% predicted: 84.46 ± 12.53 vs 100.6 ± 8.43 (p <0.01), respectively . There was no difference in the reported symptomatology of dyspnea and fatigue in lower limbs, cardiorespiratory variables and inspiratory capacity, between the groups, at the end of each test. Regarding the ISWT performance, the GA walked a distance shorter than the GC (p <0.05). For the Glitter-ADL test, GA performed the test with almost 1 minute more compared to GC (p <0.05). The EMG analysis during the ISWT showed an increase in the electrical activity of the muscles evaluated in a coordinated and similar way, in both groups, with a significant difference only for ECOM of GC in 100% of the test (p <0.05). In Glitter-ADL test, there was no difference in activation for the ESC and DM muscles. The RA and RF muscles showed greater activation in the CG, but no significant difference. Our results suggest that during the ISWT and Glitter-ADL exercise tests, asthmatic patients exhibit coordinated electromyographic activity and similar to healthy individuals, however with lower performances in both tests.