3. Results
3.1. Kinematic Description of the Spike
Figure 3 shows as an example the kinegram of player 1. The sequence shows how the player performs the run-up, the take-off, the backwards torsion of shoulder and arm on the hitting side of the body, the subsequent acceleration of these body segments in the direction of the ball, the ball impact with simultaneous body extension and the preparation of the landing. The run-up velocities differ only minimally and range for all players from 3.31 m/s to 3.49 m/s. The maximum jump height varies between 0.32 m and 0.43 m. The time intervals between take-off, ball impact and landing are again relatively stable; they range from 0.26 s to 0.16 s and 0.35 s to 0.20 s, respectively. Thus, similar to the fistball serve [7], we also found for the spike only small inter-individual variance regarding the kinematic of movement phases. However, it should be noted, that the players who participated in this study had a very similar level of performance.