In this study, three-dimensional kinematics and performance were analyzed for male and female top level and junior elite volleyball players in a spike, which is an essential offensive volleyball action. Top level players had higher impact speeds and jumping height than junior elite players for both genders and the male players had higher impact speeds and jumping height than the female players for both levels of expertise. For the analysis of the three-dimensional kinematics of the pelvis, trunk, shoulder and elbow angles and angular velocities, Statistical Parametric Mapping was used. No differences were observed for the orientation angles of pelvis and trunk, indicating a set of invariant kinematics. The pelvis and trunk angular velocities on the other hand did show many interesting differences throughout the approach, cocking and acceleration phase of the spike. The shoulder and elbow angles and angular velocities also illustrated the different strategies used for generating high impact speeds. An important conclusion was that interaction effects between gender and level of expertise were mostly observed in variables from the shoulder and elbow, whereas pelvis and trunk velocities only presented significant main effects. These differences suggest how the motion pattern of the young elite athletes will change over the following years when they gradually make the change towards the highest competitive levels.

Part one of this study described the three-dimensional kinematics of male and female top level and junior elite volleyball players during a spike. Different strategies for generating a high impact speed for the hand were observed between the groups. This part focuses on variability in coordination and performance and will use a single-subject approach for the data-analysis. The research question concerns the relationship between coordination variability and skill level. Two hypotheses exist about this relationship: a continuous decrease of variability or a U-shaped relationship when skill level increases. We used different measures of skill level during this study. The discrete measure (top level vs. junior elite) showed no difference in coordination variability. The continuous measures showed both U-shaped and linear relationships with coordination variability when data from all groups were pooled together. No relationships were observed within the groups. Together with the insight gained from the mechanical analysis from part one, knowledge about the coordination variability can be used for guiding the training and learning process of youth elite volleyball players.