Jumping performance of different roles volleyball players in the side out phase

Jumping performance of different roles volleyball players in the side out phase Introduction The aim of this study is to compare the physical effort of volleyball players of opposite positional role, focusing the analysis to the side out phase of the game, i.e. that phase in which the team starts the rally receiving. Number of jumps executed in a game have been considered as physical performance index, according to Fontani1. Given that opposite-role players have similar technical characteristics, as described by Palao2, it is hypothesized that they would perform a similar number of jumps in a game. Methods Statistical data relative to 3 volleyball games (15 sets) of a top level male team employing the 5-1 playing system were collected with the Data Video System (Dataproject s.r.l., Bologna, Italy), and used for the analysis. Jumps performed in the side out phase (K1) were divided in blocking and spiking jumps. The mean jump number for game was analysed with Chi-square tests (=0.05), comparing respectively the setter (P) vs. the opposite (O), the two hitters (S1 - S2) and the two middle blockers (C1 - C2). Results Table 1: Comparison between role and position in the side out phase Position Total Jumps (K1+ K2) K1 BLOCK K1 SPIKE Mean ± S.D. K1% Mean ± S.D.. % Mean ± S.D. % C1 112.7±2.9 46.6 12.0±2.6 23.4 39.3±3.2 76.6 C2 105.7±21.4 43.7 12.0±1.0 26.1 34.0±6.9 73.9 S1 93.0±22.0 40.6 8.0±4.0 21.2 29.7±13.3 78.8 S2 76.3±24.6 31.9 5.7±3.1 23.3 18.7±9.1 76.7 P 141.3±10.0 63.2 9.0±1.0 10.1 2.0±1.0 1.1 O 109.0±47.9 44.6 8.0±2.6 20.7 30.7±8.1 79.3 Table 1 displays the mean ± SD jump number for game for each of the considered roles in the side out phase. Jumps performed in the entire game (including the defensive phase, K2) are also reported for comparison purposes. No significant difference was shown between the considered couples of roles for blocking and spiking jumps. Besides the actions reported in the table, 79.3±8.1 additional jumps to set were performed by the setter. This was the only role involved in setting in the side out phase. Discussion/Conclusion Number of jumps referred to the entire game is similar to previous studies (Palao1, Fontani2). The new contribution of this study is a focused investigation of the K1 phase, revealing as expected no differences between opposite-role players. In the K1 phase, it is emphasized the exceptional physical effort of the setter, since he has to set as often as possible to accelerate the play. References 1. Fontani, G., Ciccarone, G. et al. (2000) SDS-Rivista di cultura sportiva. 50:14-20. 2. Palao, J.M., Santos, J.A. et al. (2006) Journal Human Movement Science 51:221-228