Influência da calha na geração de fadiga muscular em atletas da bocha paralímpica

Abstract

Introduction: The athlete of the Paralympic boccia class BC3 has a high degree of motor impairment and, therefore, uses a ramp to aid in the throwing of the ball. To improve the performance of the class BC3 athlete, in addition to the ramp design, it is necessary to understand the muscular fatigue, related to the throwing of the ball during its action in the game. Objectives: The aim of the present study was to evaluate the level of muscle fatigue generated in athletes of the Paralympic boccia class BC3 using two types of assistive device; a ramp developed in 3D printer and a conventional ramp. Material and Methods: The research sample consisted of athletes from the Paralympic boccia team from Uberlândia. To identify the muscle fatigue index, it was obtained the electromyographic signal of four muscles: right (Tpdd) and left (Tpde) descending trapezius, right (ECMD) and left (ECME) sternocleidomastoid from median frequency (MF) and normalized root mean square (RMSn) in the same ramp and comparing its electrical activity between the ramps. Three actions of athlete's throwing were analyzed: flexion, extension and hyperextension of neck with 30 ball throwings for each position with a total of 90 throwings. The tests were done in two steps. The first was performed with a conventional ramp of the athletes and the second using the new one made in 3D printer. For the normalization of the data obtained by the electromyography, the peak of the contractions exerted in each measurement was used. The data obtained by throwing the ball were analyzed by the software MiotecSuite 1.0. The normality test used was Shapiro-Wilk and the analysis of the data was performed by generalized estimating equations (GEE) by SPSS software. Results: The mean MF in the Tpde and Tpdd muscle presented significant results (p <0.001) in the neck extension in the 3D ramp. The conventional ramp presented significant results in the Tpde muscle and ECMD in the neck extension. Mean RMSn indicated significant results in the conventional ramp in the neck hyperextension of the Tpde, Tpdd and ECME muscles and in the neck extension of the ECME muscle. When comparing the mean RMSn, between the 3D ramp and the conventional ramp, it was observed that the significant values were lower in the 3D ramp in most of the heights, which suggests a signal of manifestation of early fatigue in the 3D ramp. Conclusion: Considering the configuration of the tests performed for the evaluation of the fatigue index in athletes of the Paralympic boccia, simulating a training condition, it was observed a difference in the muscular electric activation in the use of a conventional ramp and the 3D ramp by additive manufacture. The structure of the ramp can therefore interfere with the fatigue generation process.