Electromyographic analisys of biceps brachii and erector spinae muscles before and after a fatiguing dynamic test / Análise eletromiográfica dos músculos bíceps do braço e eretores da espinha antes e após um teste isotônico fadigante

ABSTRACT

The increased number of musculoskeletal injuries can be caused by the lack attention to load level, as well as the posture and time of execution of an overloaded exercise. This way, the objective of this study was to analyze the effect of repetitive barbell biceps curl exercise over biceps brachii and erector spinae muscle electromyographic parameters. Ten healthy male subjects (20,91±1,37 years), without musculoskeletal diseases, performed the biceps curl exercise until fatigue, with 25%, 35% and 45% of 1 repetition maximum. The electromyographic activity of biceps brachii and erector spinae muscles was analyzed during isometric contraction performed before and immediately after fatiguing tests. The muscular fatigue was identified through the increase of root mean square and decrease of median frequency during isometric contractions. The results demonstrated these characteristics of fatigue after fatiguing test (p<0,05) for both muscles, showing a relationship time-load dependent for these electromyographic parameters. No significant differences were found between left and right muscles in the parameters analyzed. The experimental procedures allowed identify the muscular fatigue on biceps brachii muscles and erector spinae activity during barbell biceps curl and the dependence with load and number of repetition...