Correlações entre os parâmetros oriundos das relações de força x velocidade e desempenho em testes específicos com futebolistas

Abstract

Kinetic variables such as force, velocity, and power obtained in sports movements present a strong correlation with the level of performance in different sports. In this perspective, the method proposed by Samozino et. al., (2016) starts with a kinetic analysis of the movement to explain performance phenomena through a mechanical effectiveness profile. A pertinent question to be answered is how elements of the Force-Velocity Relationship (FVxR) can relate to functional performance parameters such as change of direction ability, isometric strength, and kicking force in soccer players. The study aims to establish different strategies for evaluating strength and power in dynamic sports with technical and physical performance aspects. Seventeen male athletes from the under-20 category of a soccer team participating in research projects at the Federal University of Alagoas were randomly and conveniently invited to participate in the study. In the first session, the sample was characterized and an isometric knee extension strength test was performed. In the second session, the participants performed a change of direction test, a 20-meter sprint test, and a kicking force test. Data were compared by Student's t-test and correlation investigated by Pearson's correlation test. Statistical significance was established when P < 0.05. Fzero and Pmax of the FVxR were significantly correlated with other parameters of the 20-meter sprint - directly with the average speed (r = 0.52 and 0.66, respectively) and inversely with the times of the 5, 10, and 15-meter splits (r between -0.59 and -0.84). Vzero of the FVxR was related to the maximum (r = 0.61) and average (r = 0.52) speed of the change of direction test, as well as the maximum speed in 20 meters (r = 0.58). The vertical to horizontal force ratio was inversely correlated with the maximum speed of the 20- meter sprint (r = -0.66). Based on the results presented, it is possible to conclude that the experimentation of the videogrammetry tool is subject to future scientific validation. There is a strong association between FVxR values and sprint times. There is an association between performance in the change of direction test (agility) and FVxR measured in the parameters related to speed in sprint. However, knee extension strength and kicking force values were not related to FVxR parameters in sprint, suggesting the need for a more specific study of the relationships of these strength measures with strength, power, and speed measured in sprinting.