Relationship between flexibility level, power production and performance in the countermovement jump performed at different knee angulations

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Flexibility is a physical ability capable of assisting in the athletic performance of several sports on the court, allowing athletes greater speed and fluidity of the required movement. For the vertical jump, this ability can generate an increase in the jump height, due to mechanisms capable of accumulating energy during the eccentric phase and using the jump at the moment of propulsion, in addition to assisting in the power generated during the movement. Therefore, the objectives of the present study were to correlate flexibility with lower limb power and performance in the countermovement jump (CMJ) at three different angles of knee flexion in the eccentric phase, and to compare lower limb power and performance between the same conditions tested. Twenty-two female volleyball, basketball or handball players participated in the research. Initially, the flexibility test was performed on the Wells bench and, later, the vertical jump tests were performed in three different knee flexion conditions: CMJ80º, CMJ90º and CMJ100º. The conditions were adjusted with the aid of a manual goniometer and an amplitude controller, in order to limit the eccentric phase of the CMJ to the desired angulations. Three maximum jumps were performed for each condition, with selection of the best CMJ of each amplitude for the analysis. Data normality was analyzed using the Shapiro-Wilk test and sphericity using the Levene test. Pearson's test was used to correlate flexibility with lower limb power and performance in the CMJ, with the correlation strength (FC) established by Malina's criterion (Strong = >0.6; moderate = 0.3 to 0 .6; and weak = 0,6; moderada = 0,3 a 0,6; e fraca =