The emergence of critical incidents in Rugby Union matches using Markov chain analysis.

During a rugby match, teams are continually trying to cause instabilities of different magnitudes on each other. Once a perturbation occurs, a phase transition emerges. Markov chain analysis has the potential to investigate emerging patterns in rugby union. This study examined the probability of a critical incident (CI; penalties and tries) occurring during Rugby Union matches, and whether differences would exist between winning and losing. The Markov chain analysis was used to identify the probability of a transition from a game state to a further state, due to the analysis of the preceding state. A game phase was defined as a technical and tactical match action which occurred between two consecutive advantage lines. Contingency tables were assembled from 280 phases registered during 11 matches of Brazilian Rugby Union XV A Series Championship. The results showed that previous technical and tactical actions made from rucks had the highest probability of generating a transition phase leading to a CI. The results suggest that the winning teams adopt a more flexible approach to the environmental changes that occur throughout a game and demonstrated more flexibility during transitional state occurrences, with higher variability in technical and tactical actions related to a previous game phase.

The Markov chain analysis showed that previous technical and tactical actions made from rucks had the highest probability of generating a transition phase leading to a CI.Winning teams may adopt a more flexible approach to the environmental changes that occur throughout a game.Higher variability in technical and tactical actions related to a previous game phase was observed in winning teams.The game action leading to CI moments for winning teams involved forwards and backs, while losing teams mainly depended on the involvement of forwards and eventually on opponent errors.Markov chain analysis may be a useful and valid tool to rugby match-play analysis considering the complex system framework.

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.

Obesity impairs performing and learning a timing perception task regardless of the body position.

Obesity has been associated with poorer sensorimotor performance. However, it remains unclear whether these obesity-related impairments can be mitigated by practice. In the present study, we sought to investigate the effects of practice on performing and learning a temporal estimation task, in women with and without obesity. The experimental task consisted of synchronizing the arrival of two rectangles at a target point. Limited to the pressing of a switch, the task was intended to minimize possible muscular fatigue, self-generated perturbations to balance and the need to accelerate/decelerate body segments. Participants were allowed to choose the displacement velocity of the rectangle they controlled and were informed that they would not be offered any choice over it during a test to come. To control for the effect of different body positions on sensorimotor performance and learning, the 19 women with obesity (BMI = 40.0 + 7.33, age = 44.2 + 6.6) and 20 without obesity (BMI = 22.3 + 1.95, age = 43 + 6.9) were assigned into 4 groups, according to their BMI and body position assumed during practice (standing upright with feet together or sitting). As no significant differences concerning body position were found, the data were reanalysed disregarding this factor. Results revealed that while both groups reduced errors during the Acquisition, participants with obesity showed poorer performance (Acquisition) and sensorimotor learning (Transfer). Given the experimental task and adopted procedures, our results tend to support the hypothesis that hindered perception and/or integration of sensory information is associated with obesity.

A perceptual cue on a moving opponent improves the learning of a motor skill from aikido / Uma dica perceptiva sobre um oponente em movimento melhora a aprendizagem de uma habilidade motora do aikido

ABSTRACT The effect of different instructional foci on the learning of a motor skill of aikido was investigated. Sixty participants from both sexes with an average age of 14 practiced choku tsuki task, which consisted of hitting a target on the chest of an attacking opponent with a stick. They were divided into four groups: relaxation, with a cue about the relaxed way in which the task should be performed; low hip, with a cue about maintaining hip displacement as low as possible; perceptive, with a cue at the circular target located on the chest of the opponent as they raised their sword to attack; and control, without cues. The dependent variables included measures related to the task goals, movement pattern relative to the task components and kinematic features. Only the perceptive and low hip groups learned the motor skill. The perceptive group obtained better overall performance than the other groups. Learning choku tsuki was improved by the instructional cue "strike target as soon as sword is raised", establishing the learner's perceptive attunement to the moving opponent. Learning was also enhanced by the cue "keep hips as low as possible"; however, at a lower level than that of the perceptive cue.

RESUMO O efeito de diferentes dicas sobre a aprendizagem de uma habilidade motora do aikido foi investigado. Sessenta participantes, de ambos os sexos, com idade média de 14 anos, praticaram a tarefa choku tsuki, que consistia em acertar um alvo no peito de um oponente atacante com um bastão. Eles foram divididos em quatro grupos: relaxamento, com dica sobre a maneira relaxada como a tarefa deveria ser executada; quadril baixo, com dica sobre manter o quadril o mais baixo possível; perceptiva, com dica sobre o alvo circular localizado no peito do oponente enquanto ele levantava a espada para atacar; e controle, sem dicas. As variáveis dependentes incluíram medidas relacionadas aos objetivos da tarefa, padrão de movimento em relação aos componentes da tarefa e características cinemáticas. Apenas os grupos perceptivo e quadril baixo aprenderam a habilidade motora. Ainda, o grupo perceptivo obteve melhor desempenho que os demais grupos. A aprendizagem do choku tsuki foi aprimorada pela dica "estocar o alvo assim que levantar a espada", estabelecendo a sintonia perceptiva do aprendiz com o oponente em movimento. A aprendizagem também foi aprimorada pela dica "mantenha o quadril o mais baixo possível"; no entanto, em um nível inferior ao da dica perceptiva.

Proposta de avaliação de livros e capítulos de livros na área 21 da Capes / Proposal for the evaluation of books and book chapters for Capes area 21 / Propuesta de evaluación de libros y capítulos de libros en el área 21 de la Capes

Resumo O objetivo deste estudo foi propor um modelo de avaliação qualitativa de livros e capítulos de livros com base na percepção da comunidade de docentes da Área 21 da Capes sobre o prestígio das editoras. Noventa orientadores de programas de pós-graduação das diferentes regiões do país responderam a um questionário de avaliação da percepção do prestígio das editoras científicas. A partir do valor da percepção de prestígio, as editoras internacionais (N = 69) e nacionais (N = 97) foram ordenadas e classificadas em decis. Após, propusemos um sistema de classificação de livros e capítulos de livros de oito níveis considerando dois critérios: a) editora internacional ou nacional; e b) decil de cada editora. Os níveis de L1 a L4 referem-se às editoras internacionais (da maior para a menor percepção de qualidade), e os níveis de L5 a L8, às nacionais (da maior para a menor percepção de qualidade).

Abstract This study proposes a system to evaluate books and book chapters based on the perception of graduate program advisers affiliated to Capes (area 21) regarding the prestige of academic publishers. Ninety professors from all Brazilian regions responded to the questionnaire to assess their perception about the prestige of academic publishers. Almost all respondents (94.25%) considered the scientific quality of books as the most critical factor in determining publishers' quality. The prestige value of international (N=69) and national (N=97) publishers were divided into deciles. We proposed an eight-level system to classify books and book chapters based on two criteria: a) their international or national publishers; and b) publishers' deciles. Levels L1 to L4 refer to international publishers (from high to low quality perception), and L5 to L8 refer to national publishers (from high to low quality perception).

Resumen El objetivo de este estudio ha sido proponer un modelo de evaluación cualitativa de libros y capítulos de libros a partir de la percepción de la comunidad de docentes del área 21 de la Capes acerca del prestigio de las editoriales. Noventa orientadores de programas de posgrado de las diferentes regiones del país respondieron un cuestionario para evaluar la percepción del prestigio de las editoriales científicas. A partir del valor de la percepción de prestigio, las editoriales internacionales (N = 69) y nacionales (N = 97) fueron ordenadas y clasificadas en deciles. En seguida, propusimos un sistema de clasificación de libros y capítulos de libros de ocho niveles considerando dos criterios: a) editora internacional o nacional; y b) decil de cada editorial. Los niveles de L1 a L4 se refieren a las editoriales internacionales (de mayor a menor percepción de calidad) y los niveles de L5 a L8 a las nacionales (de mayor a menor percepción de calidad).

The anticipatory and reaction time behaviors of the futsal goalkeeper / Os comportamentos antecipatório e de tempo de reação do goleiro do futsal

ABSTRACT This study aimed to investigate the goalkeeper's anticipatory and reaction time behaviors. For this purpose, 50 kicks performed by male futsal players were analyzed. The time of goalkeeper's response to a kick was analyzed in relation to the kick outcome, court zone and distance between the goalkeeper and player who performed the kick. The goalkeeper's anticipation and reaction time behaviors were those below and above 200 ms as the time criterion, respectively, by considering the moment the player began the preparation for kicking to the moment the goalkeeper began to respond to it. Results showed that the goalkeeper performed anticipatory behaviors predominantly when (i) goals were attained and (ii) kicks were performed in the center and attack court's zones (iii) at a distance ranging from 5.97 to 7.84 meters. In these conditions, the goalkeepers' anticipatory behaviors implied ineffective performances.

RESUMO Este estudo teve como objetivo investigar os comportamentos antecipatório e de tempo de reação do goleiro. Para este fim foram analisados 50 chutes executados por jogaores de futsal. O tempo de resposta do goleiro a um chute foi analisado em relação ao resultado do chute, à zona da quadra e à distância entre o goleiro e o jogador que executou o chute. Os comportamentos de antecipação e tempo de reação do goleiro foram considerados, respectivamente, como aqueles executados abaixo e acima de 200 ms considerando o início do movimento do chutador e o início do movimento do goleiro. Os resultados mostraram que o goleiro executou comportamentos antecipatórios predominantemente quando (i) ocorreram gols, (ii) os chutes foram executados das zonas central e de ataque, (iii) de distâncias entre 5,97 a 7,84 metros. Nestas condições, os comportamentos antecipatórios do goleiro implicaram em performances ineficazes.

Análise das publicações de livros e capítulos de livro dos bolsistas de produtividade em pesquisa do CNPq da área de educação física / Analysis of books and book chapters published by physical education researchers with productivity grants from Brazil's Council for Scientific and Technological Development (CNPq) / Análisis de las publicaciones de libros y capítulos de libro de los becarios de productividad en investigación del CNPq del área de educación física

Resumo O objetivo do estudo foi analisar a produção de livros e capítulos de livro dos bolsistas de produtividade do Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) da área da Educação Física (PQ-EF), procurando entender a sua trajetória e verificar tendências das publicações e eventuais alterações nas suas características no período de 1991 a 2016. Foram analisados os currículos dos 91 bolsistas PQ-EF em curso no ano de 2017, no que diz respeito aos livros e capítulos de livro publicados, número de coautores e posição autoral dos bolsistas, por períodos definidos e por categoria de bolsistas. Os resultados mostraram um crescente aumento da produção de livros e capítulos de livro per capita e também um aumento na quantidade de autores por livro e capítulo de livro, sugerindo estratégias de publicação visando ao aumento de produtividade visualizadas na produção de artigos.

Abstract The study analyzes production of books and book chapters by Physical Education (PQ-EF) researchers who held productivity grants from Brazil's National Council for Scientific and Technological Development (CNPq), seeking to understand their trajectory and check trends regarding publications and possible changes in their characteristics in 1991-2016. The curricula of the 91 PQ-EF researchers holding productivity grants in 2017 were analyzed, with regard to books and book chapters, number of co-authors, and position among authors, for defined periods and by grant holder category. The results showed increase in the production of books and book chapters per capita and also in the number of authors per book and book chapter, suggesting publication strategies aimed at increasing productivity seen in production of articles.

Resumen El objetivo del estudio fue analizar la producción de libros y capítulos de libro de los becarios de productividad del Consejo Nacional de Desarrollo Científico y Tecnológico (CNPq) del área de Educación Física (PQ-EF), buscando comprender su trayectoria y verificar las tendencias de las publicaciones y posibles cambios en sus características en el período de 1991 a 2016. Se analizaron los currículos de los 91 becarios PQ-EF en curso en 2017, en lo que se refiere a los libros y capítulos de libro publicados, número de coautores y posición autoral de los becarios, por periodos definidos y por categoría de becarios. Los resultados mostraron un incremento creciente en la producción de libros y capítulos de libro per cápita y también un incremento en la cantidad de autores por libro y capítulo de libro, sugiriendo estrategias de publicación orientadas al aumento de productividad observada en la producción de artículos.

Trends in scientific production by physical education phd student researchers holding productivity grants from Brazil's National Council of Technological and Scientific Development (CNPq) / Tendências da produção científica dos bolsistas de produtividade em pesquisa do CNPq da área de educação física / Tendencias en la producción científica de los becarios de productividad en investigación del CNPq del área de educación física

Este estudo buscou analisar a produção científica dos bolsistas de produtividade do Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) da área da Educação Física (PQ-EF), procurando entender a sua trajetória e verificar tendências quanto a publicações de artigos e às eventuais alterações nas suas características no período de 1991 a 2016. Foram analisados os currículos dos 91 bolsistas PQ-EF em curso no ano de 2017, no que diz respeito aos artigos publicados em periódicos, número de coautores e posição na autoria dos artigos, como também a relação entre esses fatores por níveis de bolsa e tempo de término do doutorado. Os resultados revelaram um aumento expressivo da produção científica per capita e também um aumento de publicações multiautorais com número cada vez maior de coautores, sugerindo estratégias de publicação visando ao aumento de produtividade.

This study analyzes the scientific production by Physical Education (PQ-EF) PhD student researchers holding productivity grants from Brazil's National Council of Technological and Scientific Development (CNPq), in order to understand their trajectory and look into publication trends and possible changes in their characteristics in 1991-2016. The curricula of the 91 PQ-EF researchers holding grants in 2017 were analyzed in terms of articles published in journals, number of co-authors, and authors' positions in the articles, as well as how these factors relate according to productivity grant levels and time taken for completing their PhD studies. The results revealed a significant increase in per capita scientific production and also an increase in multi-author publications as well as the number of co-authors, suggesting publication strategies aimed at higher productivity.

Este estudio se propuso analizar la producción científica de los becarios de productividad del Consejo Nacional para el Desarrollo Científico y Tecnológico (CNPq) en el área de Educación Física (PQ-EF), tratando de comprender su trayectoria y verificar las tendencias con respecto a la publicación de artículos y los posibles cambios en sus características en el período de 1991 a 2016. Se analizaron los currículos de los 91 becarios PQ-EF en curso en 2017, en lo que se refiere a los artículos publicados en revistas, el número de coautores y la ubicación en la autoría de los artículos, así como la relación entre estos factores según los niveles de beca y el tiempo de finalización del doctorado. Los resultados revelaron un aumento significativo en la producción científica per cápita y también un aumento en las publicaciones de varios autores, con un número creciente de coautores, lo que sugiere estrategias de publicación destinadas a aumentar la productividad.

Motor learning in post stroke subjects: the effects of practice conditions on the temporal synchronization

Abstract AIMS The aim of this study was to investigate the effects of practice schedule on the motor learning of a synchronization timing task in post-stroke subjects. Subjects and METHODS Seventeen post-stroke individuals were assigned to the experimental group and for the control group were selected seventeen healthy individuals. At the acquisition phase, all participants performed 30 trials of a coincident timing task. Nine individuals from each group practiced constantly and eight from each group practiced randomly, with speed changes in the task. Subsequent phases included: 1) immediate transfer test and 2) long term transfer test after 3 days. Data were analyzed in relation to absolute, variable, and constant errors to assess the performance concerning accuracy, consistence, and direction of responses, respectively. RESULTS All groups increased their accuracy through the practice and were able to adapt it in different speeds. The stroke subjects were more variable in their motor responses. There was no effect of the practice schedule on motor learning, regardless the presence or absence of the neurologic damage. CONCLUSION Post stroke individuals were able to learn a synchronizing task and the capacity of adapt their performance after speed perturbation was preserved. There was no effect of the practice schedule on motor learning.

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.

Revealing the decision-making of dribbling in the sport of futsal.

This study aimed to investigate why futsal players decide to dribble. For this purpose, we analysed 396 trials comprising the dribbles (n = 132), passes (n = 131) or shots (n = 133), performed by 70 male futsal players. Passing and shooting angles, and interpersonal distance, including their rates of change (velocity and variability), were regarded as measures of interpersonal coordination tendency and a comparison was made among dribbling, passing and shooting situations. In addition, the variables identified as constraints on deciding to dribble were analysed in relation to age categories, dribbling outcomes and futsal court zone. Results revealed that passing and shooting angles, and interpersonal distance showed higher variability in dribbling than in passing and shooting situations. The findings allowed us to conclude that decision-making on dribbling was influenced by the variabilities of passing angles as well as shooting and interpersonal distance, and that success in dribbling was affected by the variability of interpersonal distance. Such variabilities were interpreted concerning their meaning of risk and/or uncertainty in the execution of motor skills.

Different Faces of Variability in the Adaptive Process of Motor Skill Learning.

This study investigated the variability by considering an action programme as hierarchically organized, which reconciles invariant and variant features of motor skills at the macro- and microstructural level of analysis. It was assumed that invariant aspects of skilled actions express the macrostructure and therefore measures of sequencing, relative size, relative timing, relative force and relative pause time. The microstructure was related to the variant aspects so that total size, total movement time, total force, and total pause time were selected as its measures. These propositions were tested in an experimental design comprised by three learning phases: a stabilisation phase that entailed a given number of trials to achieve the functional stabilization on a graphic task, followed by transfer and retention phases. In the transfer phase, the graphic task was modified to yield different demands upon skill reorganization. Two such modifications demanded parametric changes (i.e. microstructure changes), in which graphic size and drawing speed were altered. Another modification demanded structural alterations (i.e. macrostructure change), in which drawing was changed. Overall, results supported the main predictions by showing that parametric changes in the task affected the microstructure, but did not affect the macrostructure consistently. Furthermore, a structural change affected both macro- and microstructure.

Informational constraints on the emergence of passing direction in the team sport of futsal.

This study investigated compound spatial and temporal measures of interpersonal interactions purported to constrain the emergence of affordances for passing direction in the team sport of futsal. For this purpose, attacker-defender interactions in 37 sequences of play from a futsal competition in which 24 male professional players participated (M=30.04 years, SD=4.10) were filmed and analysed using TACTO software. Relative angle data were used as measures to study coordination tendencies that emerged between players during performance. Results showed that the direction for a pass emerged from relative angles between: (1) the vector from a ball carrier to ball receiver and the vector from the ball carrier to the nearest defender (70°) (p<0.01) and (2) the vector from a ball carrier to ball receiver and the vector from the ball carrier to a ball receiver's nearest defender (31°) (p < 0.01). Furthermore, passing direction was also constrained by temporal information from the emergence of both angles, since the pass was performed to attacker-defender dyads with the highest velocities of these angles (p < 0.05). Results suggested that decisions on selecting the direction of a pass in the team sport of futsal emerged at critical values of these key compound motion measures.

O ensino de habilidades motoras esportivas na escola e o esporte de alto rendimento: discurso, realidade e possibilidades / The teaching of sport motor skills in the school and the high performance sport: discourse, reality and possibilities

A massificação da prática esportiva começando pela escola tem sido sugerida como uma forma eficaz para transformar o Brasil numa potência no esporte de alto rendimento. O objetivo deste ensaio é analisar e refletir sobre o discurso, a realidade e as possiblidades de ensino do esporte na escola, tendo como pano de fundo a relação entre a Educação Física Escolar e o esporte de alto rendimento. Em outras palavras, fazer uma análise crítica para qualificar a vinculação escola-esporte de alto rendimento com o intuito de deixar claro o papel social da escola e a sua eventual contribuição para a formação de atletas, e para discutir as possibilidades reais de se ensinar o esporte na escola, particularmente as habilidades motoras, consideradas as condições em que ela se encontra...

The amplification of mass sport practice starting from school physical education has been suggested as an effective way to transform Brazil in a powerful high performance sport country. The objective of this essay is to analyze and reflect on discourse, reality and possibilities of teaching sport in the schools having as a background the relationship between school physical education and high performance sport. In other words, to carry out a critical analysis to qualify the link school-high performance sport in order to make clear the social role of the school and its eventual contribution to the formation of athletes, and to discuss the real possibilities to teach sport in the schools, particularly motor skills, considering the conditions in which they now are...

Em busca da quantidade "ótima" de prática constante na estrutura constante-variada: um olhar para a validade ecológica e a especificidade da tarefa / In searching of the "optimal" amount of constant practice in the constant-varied schedule: a looking to the ecological validity and task specificity

Este trabalho investigou os efeitos da prática constante, anteriormente à prática variada, no processo adaptativo de aprendizagem motora em razão da validade ecológica e da especificidade da tarefa. Os participantes foram 108 crianças de ambos os sexos, com idade média de 11,3 (±0,4 anos), que foram divididas entre dois experimentos envolvendo cada um a aprendizagem de uma habilidade específica: (1) rebatida do tênis de mesa e (2) tacada do golfe. Ambos os estudos contaram com três grupos de diferentes quantidades de prática constante anteriormente à prática variada (aleatória ou por blocos) e, também, duas fases (estabilização e adaptação). As variáveis dependentes foram pontos (rebatida do tênis de mesa) e acertos no buraco (tacada do golfe). Os resultados evidenciaram efeitos da especificidade da tarefa, pois permitiram inferir a existência de uma quantidade ótima de prática constante (anteriormente à variada) apenas para a aprendizagem da rebatida do tênis de mesa.

This study investigated the effects on the amount of constant practice previously to the varied practice in the adaptive process for motor learning according to the ecological validity and specificity of the task. Participants were 108 children of both sexes (11.3 ± 0.4 years). They were split into two experiments involving the learning of a specific skill: (1) hit the table tennis and (2) putt golf. Both studies involved three groups of different amounts of constant practice prior to varied practice (blocked or random), and also two phases (stabilization and adaptation). Dependent variables were scores (hit the table tennis), and the number of hits the hole (golf putt). The results showed effects of task specificity because they showed the existence of an optimal amount of constant practice (prior to the varied) only for the learning of the hit the table tennis.

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.

Aquisição da habilidade motora rebater na educação física escolar: um estudo das dicas de aprendizagem como conteúdo de ensino / The acquisition of striking motor skill in school physical education: a study of learning cues as educational con

O objetivo do estudo foi investigar o efeito das dicas verbais na aquisição da habilidade rebater na Educação Física Escolar (EFE), com foco de atenção no seu aspecto perceptivo e motor. Participaram do estudo 84 alunos de três turmas de uma escola (faixa etária entre seis a oito anos). Cada turma correspondeu a um grupo: sem dicas, com dica perceptiva e com dica motora. O experimento teve três fases: pré-teste, aulas de EFE e pós-teste. O grupo com dica perceptiva apresentou melhores resultados. Portanto, verificou-se o efeito das dicas relacionado com a especificidade da tarefa no que se refere às suas demandas de processamento. Assim concluiu-se que a dica de aprendizagem relacionada à especificidade da tarefa mostrou o seu potencial como um conhecimento que orienta os alunos em direção à melhoria da qualidade do movimento, confirmando a possibilidade de sua inclusão como conteúdo de ensino da EFE.

The purpose of this study was to investigate the effects of verbal cues on the acquisition of a striking skill, focusing on their perceptual and motor aspects. The sample of this study was made of 84 public school students aged between six to eight years old from three classrooms of the same school. Each classroom constituted a group: no cue, perceptual cue and motor cue group. The experiment was carried out in three phases: pre-test, classes with specific cue and post-test. The group which received perceptual cue showed better results. Thus, it was verified that the effects of cues depend on the specificity of the task concerning its information processing demands. It was concluded that task´s specificity related cue demonstrated its potential as knowledge for the students to guide them towards improvement of the quality of movement and confirms the possibility of its inclusion as a content to be taught in the school physical education.

Assessment of beginners' front-crawl stroke efficiency.

Efficiency in front-crawl stroke has been inferred primarily by means of the analysis of arm actions, specifically, stroke frequency and stroke length. The objective of the present study was to investigate whether swimming efficiency could be better assessed in children still learning the front-crawl stroke by analyzing the movement pattern as a whole. Forty-two children enrolled in private swimming programs volunteered to participate in the study. The task consisted of swimming 30 m as fast as possible. Three experts analyzed the movement pattern of the participants using a checklist. Both stroke frequency and stroke length were calculated. The correlation coefficients between the time taken to swim and both the stroke frequency and stroke length were not significant, but the total and components of the checklist scores were. Results indicate that the swimming efficiency of children learning the front-crawl stroke can be better assessed by analyzing their whole movement pattern.

Instrução verbal: solicitar foco de atenção não garante sua adoção e melhor desempenho / Verbal instruction: requesting an attentional focus does not ensure compliance and better performance

Os objetivos deste estudo foram verificar: a) o efeito da instrução com e sem redundância na adoção do foco de atenção externo; b) o efeito do foco de atenção externo no desempenho no nado crawl; e c) o efeito da redundância do enunciado da instrução na adoção do foco e no desempenho. Participaram do estudo 43 universitários de ambos os gêneros com idade entre 17 e 46 anos. A tarefa, nadar 25 m nado crawl em velocidade máxima, foi executada uma vez em cada uma de três condições relativas à instrução: sem foco (SF), com foco (CF) e com foco e redundância (CFR), em ordem contrabalanceada. Como registro de adoção de foco, após a execução o sujeito foi questionado sobre a efetiva adoção do foco de atenção solicitado. Como medida do desempenho, computou-se o índice de braçadas. Os resultados mostraram que nas condições CF e CFR, respectivamente, 23% e 42% dos sujeitos não adotaram o foco solicitado; que nas condições CF e CFR a frequência dos sujeitos que adotaram o foco solicitado é superior à dos que não o adotaram, e, na condição CF, em relação à CFR houve uma frequência superior de sujeitos que adotaram o foco solicitado. O desempenho não diferiu significativamente entre as três condições (p>0,05). Concluiu-se que: a) não basta solicitar que seja adotado um foco de atenção para que este seja de fato adotado; b) não houve efeitos do foco de atenção externo no desempenho; e c) a adoção de uma instrução sem redundância é maior, mas sem reflexos sobre o desempenho.

The purposes of this study were to investigate a) the effect of redundant and non-redundant instruction on external focus of attention adoption, b) the effect of adopting an external focus of attention on performance in a front crawl swimming task, and c) the effect of redundancy in the wording of a verbal instruction on the above variables. 43 college students (m/f) aged 17 to 46 swam 25 m crawl at maximum speed, once under each of three conditions: without focus instruction (SF), following a focus instruction (CF) and a redundant focus instruction (CFR), in counterbalanced order. For focus adoption control, after completing the task participants were asked about what they had focused on while swimming. As a measure of performance, time and number of strokes were taken and the stroke index was calculated. The results showed that under redundant focus instruction (CFR) condition, 42 % failed to adopt the attentional focus as asked, and following focus (CF) instruction, 23 %. Under CF condition, the frequency of participants that adopted the focus was higher than of those who did not. Performance did not differ significantly among the three conditions (p>0,05). These findings stress the need of manipulation checks in attentional focus research, regarding both performance and motor learning efficiency, as well as the need for further investigation into the relation between instruction extension and performance.

O ensino do esporte para crianças e jovens: considerações sobre uma fase do processo de desenvolvimento motor esquecida / La enseñanza del deporte para niños y jóvenes: consideraciones sobre una etapa olvidada del desarrollo motor / The teaching of sport to chidren and youth: considerations about a forgotten phase of motor development

O processo ensino-aprendizagem pode ser visto como um sistema constituído pela interação de três componentes - professor, aluno e matéria - que tem por meta promover mudanças efetivas nos comportamentos, capacidades e competências do aluno. Como numa visão sistêmica do processo ensino-aprendizagem, a função de um determinado componente implica sempre o estabelecimento de relação entre os dois componentes que restam, o papel principal do professor é estabelecer relação entre o aluno e a matéria. Neste contexto, a questão central é saber em que se basear para estabelecer essa relação. O presente ensaio parte da assunção de que o conhecimento sobre o desenvolvimento motor constitui um elemento fundamental quando a matéria de ensino é o esporte, discute uma fase desse processo que tem sido sistematicamente esquecida procurando identificar as suas possíveis causas e consequências e apresenta algumas sugestões para trabalhar com essa fase.

The teaching-learning process can be viewed as a system constituted by the interaction of three components - teacher, learner and subject matter - whose goal is to promote the effective changes in the learner´s behaviors, capacities and competences. In a systemic view of the teaching-learning process the role played by a given component always implies the establishment of relations between the two remaining components. Thus, the role of the teacher is to establish relations between learner and subject matter. The main question to the teacher is on what to rely upon to establish these relations. The present essay departs from the assumption that knowledge about motor development constitutes a fundamental element when sport is the subject matter. It discusses a phase of that process that has been systematically forgotten in the teaching of sports trying to identify possible causes and consequences, and presents some suggestions of procedures to work with that phase.

El proceso de enseñanza-aprendizaje puede ser visto como un sistema formado por la interacción de tres componentes - maestro, alumno y contenido - cuyo objetivo es promover un cambio efectivo en los comportamientos, habilidades y competencias del alumno. Como en una visión sistémica del proceso de enseñanza-aprendizaje, la función de un dado componente implica el establecimiento de relación entre los componentes restantes, el principal papel del profesor consiste en establecer la relación entre el alumno y el contenido de enseñanza. En este contexto, la pregunta central es saber en que basarse para establecer esta relación. Este ensayo parte del supuesto de que el conocimiento sobre desarrollo motor es un elemento clave cuando el contenido de enseñanza es el deporte, discute una etapa del proceso que ha sido olvidada en la enseñanza del deporte, tratando de identificar sus posibles causas y consecuencias y presenta algunas sugerencias para trabajar con esta etapa.