Interpersonal coordination tendencies and perception of visual information for decision-making in futsal.

This study investigated how futsal players visually perceived information on angular interpersonal coordination relations, between available sources such as nearest defender, goalkeeper position and ball, when deciding to shoot at goal. Experienced players (n = 180) participated in eighteen, video-recorded futsal matches, during which 32 participants wore an eye tracking device. Forty-five sequences of play were selected and edited from the moment a teammate passed the ball to the shooter, until the moment a shot was undertaken. Independent variables included the angle connecting the shooter to their closest defender and goalkeeper, and it's rate of change (velocity and variability) during performance. Then eye tracking system (TOBII PRO) was used to examine gaze patterns of shooters during task performance. Findings revealed that: (i) futsal players adapted their gaze patterns differently between key information sources when shooting confirmed as: their closest defender, goalkeeper, ball, and court floor; and (ii), the ball was the information source which was most fixated on, regardless of the characteristics of interpersonal coordination tendencies that emerged when shooting. These findings can be interpreted as evidence of functional perceptual behaviours used to regulate actions needed to ensure precise contact with the ball when shooting at goal. Further, adaptations of fixation patterns, varied between marking defender, goalkeeper, and ball, may provide functional postural orientation to facilitate a successful shot at goal.

The macro- and micro-adaptations in the football teams

Abstract Aim: This study investigated the adaptations of football teams as hierarchically organised open systems. In this type of system, the collective and individual behaviours are characterised by consistency and variability, respectively. Methods: Five professional men's football matches in the under-20 category were analysed. The team's centroid as a measure of the system's macrostructure and the distance from each player to the team's centroid (a measure of the system's microstructure) were obtained from the players' x and y coordinates of displacement on the soccer field. Cluster analyses were run using Ward's minimum variance method with Euclidean distance. Results: (i) teams showed consistency and variability in their macro- and microstructures, respectively; (ii) there was a correlation between attack and defence patterns in most game sequences; (iii) goals were scored when teams modified their macro and/or microstructure. Conclusion: Football teams showed correspondence in attack-defense patterns with macro-consistency and micro-variability throughout the match. Despite this, there was no relationship between the foregoing patterns and game outcomes. Goals were scored after changes in the team's structure.

La influencia de los constreñimientos espacio-temporales en la toma de decisiones en el área de penalti del futbol / The influence of spatial-temporal constraints on decision-making in penalty area of soccer / A influência dos constraints espaço-temporais na tomada de decisões na grande área do futebol

Este estudio investigó la toma de decisiones de jugadores dentro del área penalti en el fútbol, con base en variables espacio-temporales de coordinación interpersonal y extra personal. Fueron analizadas jugadas de remate (n= 71), pase (n= 26) y drible (n= 30), seleccionadas de 12 partidos de fútbol de un campeonato amateur en Colombia. Las imágenes capturadas fueron analizadas a través del software TACTO. Las variables espaciales y espacio-temporales utilizadas para el análisis fueron: II) ángulo de remate; III) ángulo A de pase; III) ángulo B de pase; IV) distancia interpersonal; V) velocidad y variabilidad relacionadas al cambio de cada una de esas medidas. Los resultados mostraron que, en relación a la decisión de rematar, los valores del ángulo de remate fueron superiores en comparación con el mismo ángulo cuando la decisión tomada fue la de pasar o driblar; y, en la decisión de driblar, los valores de la distancia interpersonal fueron diferentes con las situaciones en que se decidió pasar. En conclusión, os ángulos de remate y distancias interpersonales, funcionaron como parámetros de control en las situaciones de remate y drible, respectivamente

This study investigated the influence of spatio-temporal variables of interpersonal coordination on players’ decision-making within the penalty area of the soccer. We analyzed shooting events (n= 71), passing (n= 26) y dribbling (n= 30), which was choose from 12 games of an amateur Colombian championship and analysed using TACTO software. The spatiotemporal variables were: (I) shooting angle: formed by vectors liking the ball carrier (vertex) to two opponents that generated a gap in the goal; (II) passing angle A: vectors connecting the ball carrier (vertex) to his nearest defender and to a teammate; (III) passing angle B: vectors linking the ball carrier (vertex) to a teammate and to the teammate’s nearest defender; (IV) interpersonal distance: between the ball carrier and his nearest defender; (V) velocity: change rate of each of the measures, depending on the duration of the play; (VI) variability: coefficient of variation of each of the measures from the beginning to the end of the play. The results revealed that, values of the shooting angle were higher when players decide for shooting, comparing to situations in which the players decided to pass or dribble; and, the interpersonal distance was shorter in dribbling situations, comparing to passing situations. It was concluded that, the shooting angle and the interpersonal distance, functioned as control parameters in shooting at goal and dribbling situations, respectively

O presente estudo investigou a influência de variáveis espaço-temporais de coordenação interpessoal na tomada de decisões dos jogadores na grande área do futebol. Foram analisadas jogadas de chute (n= 71), passe (n= 26) e drible (n= 30), selecionadas de 12 jogos de futebol de um campeonato amador na Colômbia. As imagens capturadas foram analisadas através do software TACTO. As variáveis espaço-temporais consideradas para análise foram: i) ângulo de chute: vetores ligando o jogador com posse de bola (vértice) com os dois adversários geraram a maior lacuna no gol; ii) ângulo A de passe: vetores ligando o portador da bola (vértice) com seu marcador mais próximo e seu companheiro de equipe; iii) ângulo B de passe: vetores ligando o portador da bola (vértice) com seu companheiro de equipe e o marcador mais próximo dele.; iv) distância interpessoal: entre o atacante com posse de bola e o seu adversário mais próximo; v) velocidade: taxa de mudança de cada uma das medidas, em função do tempo de duração da jogada; vi) variabilidade: coeficiente de variação de cada uma das medidas desde o começo até o final da jogada. Os resultados mostraram que os valores do ângulo de chute foram superiores nas situações que os jogadores decidiram chutar, em comparação com as situações em que os jogadores decidiram passar ou driblar; e que, as distâncias interpessoais foram menores nas situações em que os jogadores decidiram driblar, em comparação com as situações de passe. Em conclusão, os ângulos de chute e distâncias interpessoais influenciaram na tomada de decisões do chute e drible, respectivamente

The influence of the first pass on the volleyball blockers' decision-making / A influência do primeiro passe na tomada de decisão dos bloqueadores do voleibol

ABSTRACT This study examined the information constraining volleyball blockers' decision-making as they attempted to anticipate an opponent's shot. The role of the ball flight information emerging from the interaction between the digger and the setter was investigated. In the first experiment a kinematic analysis of the ball trajectory was run in order to determine its influence on setter's action. In the second experiment players were asked to predict the block location by watching a video involving (i) the complete ball flight or (ii) only the final ball flight. It was verified that the setting occurred more frequently to the outside hitter when setter was far from the net (experiment 1). In addition, it was found that the ball flight information and the setter position guided the blockers anticipation (experiment 2). These findings suggest that the passing information can provide support for blocking anticipation in specific situations in which the ball flight was characterised by high altitudes.

RESUMO O presente estudo examinou a informação que constrange a tomada de decisão dos bloqueadores no jogo de voleibol, referente à antecipação da jogada adversária. Foi investigado o papel da informação do voo da bola, que emerge da interação entre o passador e o levantador. No primeiro experimento foi feita análise cinemática da trajetória da bola para determinar sua influência na ação do levantador. No segundo experimento jogadores tinham que prever o local em que ocorreria o bloqueio, após assistir a dois tipos de vídeo que continham: (i) o voo completo da bola ou (ii) apenas o voo final da bola. Verificou-se que o levantamento ocorreu mais frequentemente para o jogador da posição 2, quando o levantador estava mais distante da rede (experimento 1). Adicionalmente, verificou-se que a informação de voo da bola e a posição do levantador guiaram a antecipação dos bloqueadores em algumas situações (experimento 2). Os achados sugerem que a informação do passe pode fornecer suporte para a antecipação de bloqueadores em situações específicas, nas quais o voo da bola seja caracterizado por grandes alturas.

Effects of instructional focus on learning a classical ballet movement, the pirouette.

This study investigated how changes in the focus of instruction might affect the learning by individuals who are not trained dancers of a complex classical ballet movement, the pirouette. Seventy-two volunteer college students were divided into six groups according to the focus of instruction: (1.) head, (2.) arms, (3.) trunk, (4.) knees, (5.) feet, and (6.) controls. In the acquisition phase, all groups performed 160 trials, over 2 consecutive days. At the beginning of each day, they received verbal instruction regarding some of the general principles involved in performance of the pirouette and viewed a video that illustrated those principles. Each group (head, arms, etc., exclusive of controls) was then given specific directions for controlling focus on its body part while performing the movement. After a week, all participants were asked to complete a retention test, with no additional instruction. The trials were videotaped with two cameras (frontally and laterally), and the results were analyzed by 10 specially trained examiners, utilizing Movement Pattern and Error of Performance measures. They revealed that all groups improved in the acquisition phase, and the improvement was maintained in the retention test. No differences were revealed between groups. It was concluded that generalized instruction in basic principles of the movement was more effective than focus on specific body parts in the teaching and learning of the pirouette.