INTRODUCTION: In volleyball, the volleyball spike approach movement (SM) represents one of the more sophisticated attack actions and the spike after it, is the most important ability to win a game (1). The use of nonlinear tools like entropy can be a good alternative to explore the nature of human movement and its relationship with coordinative development (2), reflecting changes in movement variability (MV) during the movement execution and overt time. SM oscillations can be evaluated through entropy calculation techniques (3) that allow to identify variability from a spatiotemporal perspective. In general, change in movement complexity with practice find that, the complexity of the attractor dynamics (pattern of expected values of the movement) could be reduced as a function of practice (4), furthermore, athletes manage to reduce the variability of their sports movements (5), in volleyball game position puntas are the player who realizes more SM in practices and competition during a season (6). The aim of this study was to identify the differences in human movement variability (MV) between game position in SM with and without ball constraint. METHODS: One WIMU(Realtrack systems) were placed in a belt to forty eight female first division players in 4 different game positions: Punta(Mean ±SD: Age16,83±3,62; Height: 1,76±0,06; Weight: 65,95±7,15), Central (Mean ±SD: Age 18,42±3,40; Height: 1,82±0,03; Weight: 72,57±6,39), Colocadora (Mean ±SD: Age 17,00±3,51; Height: 1,77±0,02; Weight: 68,67±5,03), Libero (Mean ±SD: Age 19,80±3,37; Height: 1,71±0,04; Weight: 63,88±5,39) who performed SM in both conditions (with ball and without ball). The players performed an eight minutes standardized warm-up after which they realized four sets of six SM, two of them with ball and two of them without ball in random order, completing eight series performed in two sessions on different days. The human movement variability was analysed with entropy values in Sample Entropy (SampEn). RESULTS: The SampEn response variable was analysed using a Mixed linear Model, where with or without ball is the main variable explanatory and, game position as a secondary variable explanatory. In SampEn without ball (Punta=0,153; Central=0,156; Colocadora=0,155; Libero=0,163) with ball (Punta=0,072; Central=0,079; Colocadora=0,074; Libero=0,081). Without ball there is no difference between positions, with ball position Punta is different to Central (p = 0,0117) and to libero (p = 0,0019). CONCLUSION: At game position as a constraint, the MV decreases significantly between the position Punta and the rest of game positions, as in the conditions of the study, we could consider the Puntas probably are who realizes more SM in practices and competition (6), up to 40,000 during one season (7).
© Copyright 2022 27th Annual Congress of the European College of Sport Science (ECSS), Sevilla, 30. Aug - 2. Sep 2022. Julkaistu Tekijä Faculty of Sport Science - Universidad Pablo de Olavide. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator