Water polo throwing velocity and kinematics: differences between competitive levels in male players

Aim. In water polo, throwing is one of the most important and frequently used technical skills for the player. There is no scientific literature that provides information about differences in throwing between elite and sub-elite water polo players. The aim of our study was to study differences in throwing velocities and kinematic variables in elite and sub-elite level male water polo players. Methods. We considered the variables under standardized conditions during a typical motion, the five-meter shot (penalty). Thirty-four athletes from the Men's First Division Water Polo Championship and forty-two players participating in the National Fourth Division League, took part in the study. Video analysis measures were taken with high-speed digital cameras and the videos were analyzed offline with Dartfish 5.0 Pro. Results. No correlation was found between body mass, height and throwing velocity. Elite players had higher values for ball speed (22.8 +/- 2.4 m/s for elite team and 18.4 +/- 1.7 m/s for sub-elite team; P=0.002) and greater elbow angle (157.5 +/- 10.3 degree for elite team versus 146.7 +/- 8.9 degree for sub-elite team; P=0.002). In elite team the throwing time was lower (165.6 +/- 22.2 and 188.6 +/- 23.9 ms, respectively; P=0.05) and the shoulder angle was smaller (115.1 +/- 10.3 and 123.8 +/- 12.4 degree, respectively; P=0.03) than in sub-elite team. Head height was significantly greater in elite players (elite players 71.1 +/- 8.7 cm, sub-elite players 65.6 +/- 6.2 cm; P=0.03). Conclusion. Differences in kinematic characteristics between elite and sub-elite players were showed. Differences in elbow and shoulder action must be considered both in training and injury prevention.