Reproducibility and Validity of a Stroke Effectiveness Test in Table Tennis Based on the Temporal Game Structure.

Purpose: This study aimed to develop a stroke effectiveness test in table tennis based on the temporal game structure to assess the ball speed and ball placement of the players, with a purpose to analyze its reproducibility and validity. Methods: Nineteen male table tennis players participated in this study. The test was performed twice during the first session and once during the second session to assess the intrasession and intersession reproducibility, respectively. Moreover, the test was examined on its ability to discriminate between regional (n = 10) and local performance-level (n = 9) players and on the relationship between the test results and the table tennis performance to assess the discriminant and concurrent validity, respectively. In general, the test consisted of 11 simulated rallies of 2-5 balls with the effort and rest ratio of 0.5, and focused on attack with offensive strokes at defensive balls delivered by a robot randomly between the left and right positions on the table. Results: Ball speed, ball placement, and ball speed-ball placement index showed satisfactory reliability (ICC range 0.78-0.96, P < 0.05) and agreement (CV range 2.7-16.2%) outcomes. Additionally, the Bland-Altman plots show the systematic error of the analyses closer to 0, and that most values were within the limits of agreements. Concerning validity analyses, regional players had higher scores of ball placement (+51.3%; P = 0.01, ES = 1.33) and ball speed-ball placement index (+56.1%; P = 0.0009, ES = 1.87) as well as made fewer errors (-25.4%; P = 0.017, ES = 1.20) than local players. Moreover, ball placement (r = -0.79, P = 0.04), ball speed-ball placement index (r = -0.78, P = 0.04), and percentage error (r = 0.88, P = 0.01) presented a strong and significant correlation with table tennis performance. However, ball speed was slightly different between the regional than local players (+1.7%; P = 0.78, ES = 0.13) and this variable was not related to table tennis performance (r = 0.32, P = 0.49). Conclusion: Our findings show evidences that the test is reproducible. Moreover, discriminant and concurrent validity are confirmed for ball placement and ball speed-ball placement index.

Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques.

In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players' movement patterns during goalball matches that can be used to plan more effective training.

Nonlinear pedagogy and the implications for teaching and training in table tennis

Aim: It is to propose a game-based and player-centred approach to teaching table tennis using nonlinear pedagogy insights. Methods: This is an essay which offers a well-reasoned articulated nonlinear pedagogy perspective on coaching and teaching table tennis issues Results: It offers the description of a propose based on a player-centred and game-based approach for table tennis supported by nonlinear pedagogy, illustrating examples of how to apply nonlinear pedagogical principles to design representative learning tasks in order to adapt them to learners' skills level. Conclusion: A novel perspective for teaching and training table tennis is presented here and we intend that this proposal may help coaches to design an effective learning environment.(AU)

Technical Indicators registered as a function of the playing time in Brazilian basketball / Indicadores de desempenho registrados em função do tempo no basquetebol brasileiro

Abstract Basketball performance analysis using technical indicators dissociated from the moment they occurred in the game seems to no longer respond to emerging issues of the game as it does not identify the periods when a team's offensive efficiency has increased or decreased. The aim was to characterize and compare the technical indicators in the positive and negative periods and in the whole game of winning and losing teams in men's professional basketball. Fourteen games of professional men's teams of the "Novo Basquete Brasil" Championship in the regular 2011/2012 season were filmed and analyzed. The Kolmogorov-Smirnov test was used to verify data normality. The independent T test was used for variables with normal distribution and the Mann-Whitney test for variables that did not present normal distribution, in order to compare teams' performance. Analysis in the whole game showed that winning teams had significantly higher averages in successful 3-point field goals but in the positive periods, they showed higher averages for successful free throws, successful layups, defensive rebounds and defensive fouls, and in negative periods, losing teams made more defensive and offensive fouls. The teams' performance in the whole game may not elucidate the determinant indicators for building the difference in the scoreboard. It is suggested that coaches should identify the periods of best and worst teams' performance in the game and the indicators involved, preparing teams to overcome the negative periods and obtain more positive periods in the game.

Resumo A análise de desempenho no basquetebol a partir de indicadores técnicos dissociados do momento em que ocorreram no jogo parece não mais responder às questões emergentes do jogo, pois não se identificam os períodos em que a eficiência ofensiva de uma equipe aumentou ou diminuiu. O objetivo foi caracterizar e comparar os indicadores técnicos nos períodos positivos, negativos e no jogo todo, entre equipes vencedoras e perdedoras no basquetebol profissional masculino. Foram filmados e analisados 14 jogos de equipes profissionais masculinas do Novo Basquete Brasil, na temporada regular de 2011/2012. Recorreu-se ao teste de Kolmogorov-Smirnov para verificar a normalidade dos dados. Para as variáveis com distribuição normal recorreu-se ao teste T de amostras independentes e para as variáveis que não apresentaram distribuição normal ao teste de Mann-Whitney, a fim de comparar o desempenho das equipes. A análise no jogo todo mostrou que as equipes vencedoras tiveram médias significativamente maiores em arremessos de três pontos certos, já nos períodos positivos tiveram em lances livres certos, bandejas certas, rebotes defensivos e faltas defensivas. Nos períodos negativos as equipes perdedoras fizeram mais faltas defensivas e ofensivas. O desempenho das equipes no jogo todo pode não elucidar os indicadores determinantes para a construção da diferença no placar. Sugere-se que os treinadores identifiquem os períodos de melhor e pior desempenho das equipes no jogo e os indicadores neles envolvidos, para preparar as equipes para superar os períodos negativos e obter maior número de períodos positivos no jogo.

Interpersonal coordination analysis of tennis players from different levels during official matches.

The purpose of this study was to assess the interpersonal coordination during official male tennis matches in players of different skill levels. Players' trajectories of three levels (Juvenile, ATP-Future, ATP-250) were obtained using video-based tracking system. A vector coding technique was applied to obtain players' interpersonal coordination in four coordination patterns: "anti-phase", "in-phase", "serving player phase" and "returning player phase". These patterns allowed identification of the nature of the coupling and lead/lag relations between players. In all categories, players presented higher degree of "anti-phase" and "serving player phase" (when only the serving player is moving on the court or his opponent is moving with a time lag) coordination. Young players spent more time in "serving player phase" during lateral displacements than professional players. On the other hand, professional players spent more time in "returning player phase" (when only the returning player is moving on the court or his opponent is moving with a time lag) during antero posterior displacements, than young players. Interpersonal coordination did not change from the first to the second set of the match, showing that tennis players maintain their displacement characteristics and strategy, independently of proficiency level. The vector coding technique allowed to identify new coordination patterns in tennis, providing additional information about tennis dynamics and how players from different categories and proficiency levels behave during the matches.

Pedagogia do esporte e tênis de mesa: novas perspectivas para o ensino-treino do efeito na iniciação esportiva tardia / Pedagogy of sport and table tennis: new perspectives for teaching-training of the effect on late sports initiation / Pedagogía del deporte y tenis de mesa: nuevas perspectivas para la enseñanza-entrenamiento del efecto en la iniciación deportiva tardía

O ensino do tênis de mesa permanece sustentado pelo método tradicional de ensino, que se baseia nas teorias empiristas e inatistas, também denominadas metodologia analíti-ca/tecnicista. Nos últimos anos, algumas propostas têm buscado superar esse tipo de aborda-gem, no entanto, nenhuma delas trata do ensino dos efeitos na perspectiva das tendências atu-ais da Pedagogia do Esporte. O efeito é um dos principais fatores com um papel significativo para vencer uma partida de tênis de mesa. Este ensaio bibliográfico de caráter descritivo-propositivo tem por objetivo, portanto, discutir o ensino do tênis de mesa pautado nessas ten-dências atuais, contextualizando-o com os demais esportes de rede divisória, em especial os de raquete, focando no ensino-treino do efeito e exemplificando alguns tipos de jogos.

The teaching of table tennis remains supported by traditional method of teaching, which is based on empiricists and innatists theories, also called analytic/technicist methodology. In recent years, some proposals have been seeking to overcome this approach, however, none addresses the learning of spin based on the current trends of Sport Pedagogy. Spin is one of the main factors that play a significant role in winning table tennis matches. Therefore, this bibliographic, descriptive and propositional study aims to discuss the table tennis teaching based on these current trends, put it into context with other net sports, mainly racket sports, focusing on the teaching-training of spin and giving examples of some types of games.

La enseñanza del tenis de mesa continúa apoyado por el método tradicional de enseñanza, que se basa en las teorías empiristas e innatistas, también llamados metodología analítica / tecni-cista. En los últimos años, algunas propuestas han buscado superar ese tipo de enfoque, sin embargo, ninguno de ellos se refiere a la enseñanza de los efectos de la perspectiva de las tendencias actuales de la Pedagogía del Deporte. El efecto es uno de los principales factores que tienen un papel importante para vencer un partido de tenis de mesa. Este ensayo biblio-gráfico de carácter descriptivo-proposicional tiene como objetivo discutir la enseñanza de tenis de mesa con base en esas tendencias actuales, contextualizándolo con los otros deportes de red divisoria, en particular los de raqueta, se centra en la enseñanza-entrenamiento del efecto y ejemplificando algunos tipos de juegos.

Analysis of the distances covered and technical actions performed by professional tennis players during official matches.

The purpose of this study was to analyse the physical and technical performances of professional tennis players during official matches. The trajectories of eight players were obtained during matches, using an automatic tracking method. The distances covered and technical performances were analysed for the first and second sets. The athletes covered (mean ± standard deviation) a total of 1702.4 ± 448.2 m in the first set, 1457.6 ± 678.1 m in the second set and 3160.0 ± 880.1 in the entire match. No differences were found between the sets for the physical variables (lateral and forward displacements, distance covered per rally, per game and per set, and the percentage of time spent in each range of velocity). However, the distances covered by the athletes during the rallies in which they were serving (median = 5.2; interquartile range (IQR) = 6.7 m) were statistically smaller than when they were returning (median = 6.2; IQR = 7.7 m). Forehand ground stroke proficiency decreased from the first (mean ± standard deviation: 75.2 ± 4.11%) to the second set (mean ± standard deviation = 65.5 ± 14.3%). In conclusion, tennis players did not present reduced physical performance from the first to the second set.

INTENSITY IN PROFESSIONAL BASKETBALL LEVEL MATCHES: AN APPROACH USING TOTAL TIME AND LIVE TIME SITUATIONS / INTENSIDAD EN LOS PARTIDOS DE BALONCESTO A NIVEL PROFESIONAL: UN ENFOQUE UTILIZANDO SITUACIONES DE TIEMPO TOTAL Y TIEMPO EN VIVO / INTENSIDADE EM JOGOS DE BASQUETEBOL NO NÍVEL PROFISSIONAL: UMA ABORDAGEM USANDO SITUAÇÕES DE TEMPO TOTAL E TEMPO AO VIVO

The objective of this study was to characterize the basketball intensity in official matches through players' heart rate during professional level competitions. Ten players in six games were analyzed. The quantification of time spent in each zone was based on %HRmax recorded for each player in each quarter played. The first quarter presented a HR response of 169.9 beats.min-1 during the total time and 173.5 beats.min-1 during active time. The relative values in the first quarter for both the total and active time were 92.5% and 94.0% HRmax, respectively. The highest HRmax zones presented longer predominance in comparison to other HRmax zones. It is recommended the prescription of higher intensities to the lower level leagues. The application of intermittent exercise, with an individual intensity between areas of moderate intensity and high HR%, may be interesting.

El objetivo fue caracterizar la intensidad de partidos oficiales de baloncesto desde la frecuencia cardíaca de los jugadores en competiciones de nivel profesional. Se analizaron 10 jugadores de baloncesto de élite masculinos, en seis partidos oficiales durante la temporada regular de la liga profesional. La cuantificación del tiempo gastado en cada zona se basó en el porcentaje de FCmax registrado para cada jugador en cada cuarto jugado. El primer cuarto presentó una respuesta de FC de 169,9 lat.min-1 durante el tiempo total, y 173,5 lat.min-1 durante el tiempo real. Los valores relativos en el primer cuarto, tanto en el tiempo total como el tiempo real, fueron 92,5% y 94,0% de FCmax, respectivamente. Las zonas de FCmax de mayor intensidad presentaron predominancia superior, en comparación con otras zonas de FCmax. La implicación práctica es prescribir ejercicios de mayor intensidad que los que se presentan durante los juegos de ligas de nivel inferior. Un programa de entrenamiento podría ser interesante si se enfoca en la aplicación de ejercicios intermitentes con intensidad individual desde zonas de FC moderadas a las más altas.

O objetivo foi caracterizar a intensidade dos jogos de competição de basquetebol por meio da frequência cardíaca dos jogadores nas competições profissionais. Analisaram-se 10 jogadores em seis jogos. A quantificação do tempo de permanência na cada área baseia-se no valor de FCmax recolhidos para a cada jogador na cada quarto jogado. O primeiro quarto apresentou respostas da FC de 169,9 bat.min -1 durante o tempo total e 173,5 bat.min -1 durante o tempo ativo. Os valores relativos para o primeiro quarto, tanto para o tempo total como o ativo, foram 92,5% e 94,0% de FCmax, respectivamente. A zona FCmax de maior intensidade mostrou maior prevalência em comparação com outras zonas. Recomenda-se prescrever intensidades superiores às séries de campeonatos de nível inferior. O aplicativo do exercício intermitente, com uma intensidade individual entre as zonas de intensidade moderada e alta de HR%, pode ser interessante.

The effect of the maintaining the ball possession on the intensity of games

The use of small-sided games (SSG) for soccer training has increased considerably in recent years. Tactical principles can influence the intensity and the movement of soccer players during training. The aim of this study was to evaluate the influence of maintaining possession of the ball on the intensity and the time of motion characteristics of players during training in games. Eleven athletes of the U-20 category of a professional club in São Paulo, Brazil, participated in this study. To check the influence of the tactical principle, we used a game control and an experimental game in three different field dimensions and number of players. The results show that possession of the maintenance rule influences the intensity of the games (p <0.05). However, it is concluded that the rule is fundamental for training through games.

Análise cinemática das distâncias percorridas por jogadores de basquetebol de elite durante um jogo / Kinematic analysis of the distances covered by basketball elite players during a game

Introdução: os esportes coletivos têm se tornado um objeto de investigação científica em diversas áreas do conhecimento, e um desses esportes é o basquetebol. Entre os métodos de investigação das múltiplas variáveis esportivas está a videogrametria, que a partir de filmagens pode fornecer a posição dos jogadores em função do tempo. Objetivos: o objetivo geral desse trabalho foi analisar as distâncias percorridas por jogadores de basquetebol de uma equipe de elite, nos jogos como mandante, por videogrametria. Métodos: foi filmado um jogo da temporada 2011/2012 do Novo Basquete Brasil (NBB). Após a aquisição das sequências de imagens, foi realizado no Sistema Dvideo (FEF-Unicamp, Campinas, Brasil) o rastreamento manual da posição de todos os jogadores, durante toda a partida, e a reconstrução 2D da posição em função do tempo, em relação a um sistema de referência real definido na quadra. Resultados: foram encontradas diferenças significativas nas distâncias percorridas entre quartos para bola viva (p = 0.002), e entre os quartos para bola morta (p = 0.001). Conclusão: as análises das distâncias percorridas totais, distâncias percorridas por minuto e tempos jogados de jogadores por jogo, por período de jogo, em bola viva (cronometro ativo) e bola morta (cronômetro parado) apresentaram diferenças importantes para a descrição de parte do volume dos esforços realizados o que pode auxiliar técnicos e preparadores físicos para o treinamento dos atletas.

Introduction: team sports have become an object of scientific investigation in several areas of knowledge, and one of those sports is basketball. Among the methods of investigation of multiple variables is videogrammetry sports, that can provide filming from the position of the players with respect to time. Objectives: the aim of this study was to analyze the distances covered by basketball players of an elite team in the game as principal, for videogrammetry. Methods: We filmed a game of the 2011/2012 season of the New Basketball Brazil (NBB). Following the acquisition of image sequences, it was held at Dvideo System (FEF-Unicamp, Campinas, Brazil) manual tracking of the position of all the players throughout the match, and the 2D reconstruction of the position versus time, for a real reference system defined on the court. Results: there were significant differences in the distances between periods for live ball (p = 0.002), and between the rooms for dead ball (p = 0.001). Conclusion: the analysis of the total distance covered, distance covered per minute and played times players per game, per game period, live-ball (active timer) and dead ball (stopped clock) showed important differences for describing part of the volume the efforts which can help coaches and trainers for the training of athletes.

Technical and tactical soccer players' performance in conceptual small-sided games / Desempenho técnico e tático de jogadores de futebol em jogos reduzidos conceituais / Rendimiento técnico y táctico de jugadores de fútbol en juegos reducidos conceptuales

Conceptual small-sided games (CSSGs) may be interesting as a methodology for training soccer players given its connection to the unpredictability that is inherent to soccer. Our aim was investigate, through videogrammetry, if the technical and tactical principles promoted through the adoption of distinct rules from two distinct CSSGs (maintaining ball possession; and progression to the target) would actually be achieved. The study included 24 athletes assigned to 6-player teams. Our data showed that the CSSGs' organising principles create situations with differing levels of difficulty that obey the propositions of maintaining ball possession and progression to the target, i.e., CSSGs permit systematic training on technical and tactical components in order to emphasize the concepts adopted in this study in games context. Our data credit the CSSGs for teaching technical and tactical lessons that, when coupled with adequate physical conditioning, can facilitate a player's capacity to merge thoughts and events in different situations.

A utilização de jogos reduzidos conceituais (JRC) pode ser uma metodologia de treino interessante para treinar a imprevisibilidade inerente ao jogo de futebol. Nosso objetivo no presente estudo foi investigar por videogrametria os princípios técnico-táticos adotados em resposta as respectivas regras de dois jogos reduzidos conceituais distintos (manutenção de posse de bola e progressão ao alvo). Participaram do estudo 24 atletas separados em equipes de 6 jogadores. Nossos dados comprovaram que os princípios organizadores dos JRC criam situações distintas com graus de dificuldade diferentes. Ou seja, é possível sistematizar o treinamento dos componentes técnicos e táticos de forma a enfatizar os conceitos adotados neste estudo e inseridos no contexto do jogo. Nossos dados credenciam os JRC para o aprendizado de situações técnico táticas que, aliadas ao condicionamento físico adequado podem contribuir para produzir um jogador treinado para aproximar cada vez mais pensamentos e ações em situações diversificadas.

El uso de los juegos reducidos conceptuales (JRC) puede ser una interesante metodología para entrenar a la imprevisibilidad inherente en el juego de fútbol. Nuestro objetivo en este estudio fue investigar por videogrametría los principios técnico-tácticos adoptadas en respuesta a las respectivas reglas de dos JRC distintos (posesión del balón y la progresión a la meta). El estudio incluyó a 24 atletas divididos en equipos de 6 jugadores. Nuestros datos muestran que los principios de organización de los JRC crean diferentes situaciones con diferentes grados de dificultad. Es decir, es posible sistematizar el desarrollo de los componentes técnicos y tácticos de una manera a enfatizar los conceptos adoptados para este estudio en el contexto del juego. Nuestros datos acreditan JRC para el aprendizaje de situaciones técnicas tácticas que, junto con la preparación física adecuada puede ayudar a producir jugadores capacitados a unir cada vez más pensamientos y acciones en diferentes situaciones.