KINEMATIC DIFFERENCES IN LEFT-RIGHT SIDE IN BLOCKING AMONG COLLEGE WOMEN'S VOLLEYBALL PLAYERS IN JAPAN

Abstract

In recent years, the attacking tactics of top-level teams have been dominated by a combination of four attackers. The basic approach to defending against this move is to block in the direction of the toss (Read Block System). This study compares and examines the difference between the left and right sides of the crossover step of women's volleyball players using the read block system. Fifteen Japanese college women's volleyball players (age: 20.1±1.1 years, height: 169.3±5.5 cm) were eligible for the study. A time-synchronized 16 camera Mac3D optical motion capture systems (Motion Analysis Co.) and 10 force plates (Tec Gihan Co.) were used to determine three dimensional (3-D) coordinates of 38 retroreflective markers. The players were told that the toss from the setter would go up randomly in one of the left or right direction, and they were asked to block in response to the toss from the centre of the net. The results showed that the performance of the jump height (p = 0.04, d =0.50), maximum block reach (p = 0.01, d =0.51), and motion time (p =0.02, d =0.75) was better than the left, and the effect size was large. Since most of the subjects in this study were right-handed (two of the Opposites were left-handed), it is assumed that they tended to perform better on the left side, which is a block stepping similar to spike stepping. However, some players may not use the spiking hand, so individualized instruction is required.