Kinematic Factors of Off-Speed and Power Spike Techniques in Volleyball

Abstract

The aim of this study was to compare the selected kinematics factors of power and off speed spikes of junior elite volleyball players of India and obtain insights into the techniques for off speed spike motion. The subjects selected for this study were twelve male junior national volleyball players of Uttar Pradesh state team. The purposive sampling technique was used. All subjects had been participating in 39th Junior National volleyball Championship for boys and girls held at Shari Dungargarh, Bikaner, Rajasthan (India) from 22-12-2012 to 28-12-2012. All of them had practiced volleyball regularly for the last three years and participated in Sub-Junior National Championships. They were considered skilled and their technique was treated as stabilized. The mean age, height and body weight of intervarsity players were 16 years (± 2.28 years), 177.77 cm (± 5.43 cm) and 64.67 kg (± 5.95 kg). All subjects in this study were right-handed volleyball players. The performance of spike was recorded by the score in the spike which was obtained by using three point scales by the three judges. The video camera (Casio Exilim EX-F1) was used for filming. The subjects were made to take three trials only. The 300 frames per second as obtained by the use of high speed videography.The selected moments were analyzed (the best trial) by Silicon coach Pro-7 software. Only best spike frame was recorded and developed into the stick figures from which various kinematic variables were obtained.

The results revealed that there is no significant difference between off speed spike and power spike technique in relation to all angular kinematic factors i.e.shoulder angle, elbow angle, wrist angle and body inclination. This study also showed that the kinematic variables of pre-impact arm swing speed and post-impact ball speed were not significantly varied in both techniques. The result has showed that the calculated‘t’ values of all the selected variables were less than tabulated ‘t’ value at 0.05 level of significance with 10 degree of freedom. These results lead to the assumption that the technique of spike jumps seems to be highly individual in top level junior volleyball players.

Keywords: Kinematic, Off-speed spike, Power spike,