The influence of expertise and experimental paradigms on the visual behavior of tennis athletes in returning a serve

To return a serve, one must pick up information from the server’s kinematics and anticipate the ball trajectory. Although the perceptual requirements are important, the literature diverges in terms of the differences between experts and novices as well as the importance of the experimental paradigm (in-situ vs. video-based) for the results. This study aimed to address both concerns. We compared experts’ (n=7, 20.6±1.1 years of age) and novices’ (n=7, 20.0±0.4 years of age) visual pattern when returning a serve (Experiment 1) and the influence of the experimental paradigm in experts (Experiment 2). Experts fixated more and longer the upper body and ball, while novices showed a more distributed pattern and with longer fixations outside of the server’s body. Also, the pattern was different when comparing in-situ and laboratory settings, differing mainly in fixation frequency. The influence of expertise was observed in qualitative (relative) and quantitative (absolute) measures of visual behavior with the setting having an important influence. Thus, studies should be as close to the actual situation if trying to understand experts’ behavior

A comparative study of the mastery of fundamental movement skills between different cultures

It has been suggested that guidance, encouragement and opportunity are crucial factors for children’s motor development. They are especially important to promote the mastery of fundamental movement skills. The present study investigated the association between two elements related to those factors – proposed curriculum of physical education and the most popular sport in a given country – and the incidence of mastery in the FMS in children from 4 to 10 years of age. In order to carry out a cross-cultural comparison, three studies from different countries (Portugal, China and USA) that used TGMD-II were selected. The results indicated association between proposed curriculum and the number of children mastering FMS. This association increases in older age groups of children from USA, the most structured curriculum related to FMS, presenting the highest average percentage of mastery.  Additionally, we did not find association of the most popular sports in a given country with the mastery of the related skill. These results are interpreted as evidence for the importance of guidance on the mastery of FMS

Efeitos de diferentes focos de atenção na performance motora de uma tarefa de agilidade em crianças

<p>O objetivo do estudo foi investigar se instruções de foco externo de atenção comparado ao foco interno e sem foco determinado afetariam de forma diferente a performance motora de crianças. Adicionalmente, buscou-se mensurar a adoção das instruções prescritas sobre o foco de atenção pelos participantes. Vinte e três crianças, de ambos os sexos, com idade média de 10.04 ± .06 anos realizaram uma tarefa motora de agilidade em três condições diferentes: foco externo, foco interno e sem foco determinado. Estes realizaram cinco tentativas de prática de cada condição experimental em dias distintos e tiveram seus tempos de movimento registrados. Após cada tentativa, todos os participantes responderam a uma pergunta em relação ao foco de atenção utilizado. As análises apontaram superioridade da condição sem foco determinado e de foco interno em relação à condição foco externo. Em relação à adoção do foco de atenção, as crianças se utilizaram prioritariamente dos focos de atenção instruídos pelo experimentador. Porém, na condição sem foco determinado utilizaram o foco externo (65%) na maioria das tentativas. Conclui-se que as instruções relacionadas ao foco de atenção externo não beneficiaram a performance motora de uma tarefa de agilidade em crianças.</p

Testing Seefeldt&rsquo;s Proficiency Barrier: A Longitudinal Study

The idea that proficiency in the fundamental movement skills (FMS) is necessary for the development of more complex motor skills (i.e., the proficiency barrier) and to promote health-enhancing physical activity and health-related physical fitness levels is widespread in the literature of motor development. Nonetheless, to the best of our knowledge, there is no study assessing whether children presenting proficiency below a specified proficiency barrier would demonstrate difficulty in improving performance in more complex skills&mdash;even when subjected to a period of practice in these complex skills. The present study tested this. Eighty-five normal children (44 boys) aged 7 to 10 years participated in the study. The intervention took place during 10 consecutive classes, once a week, lasting 40 min each. Six FMS (running, hopping, leaping, kicking, catching and stationary dribbling) and one transitional motor skill (TMS) (speed dribbling skill) were assessed. The results showed that only those who showed sufficient proficiency in running and stationary dribbling before the intervention were able to show high performance values in the TMS after intervention. In addition, in line with recent propositions, the results show that the basis for development of the TMS was specific critical components of the FMS and that the barrier can be captured through a logistic function. These results corroborate the proficiency barrier hypothesis and highlight that mastering the critical components of the FMS is a necessary condition for motor development

O efeito do estabelecimento de metas específicas no desempe-nho e comprometimento de indivíduos experientes no lançamento do basquetebol

Este estudo investigou os efeitos da meta estabelecida no desempenho e aderência de indivíduos ex-perientes. Foram realizadas três fases: pré-teste, prática e pós-teste. Treze atletas universitários (24.3±4.8 anos de idade) foram divididos em dois grupos onde realizaram arremessos de três metros do basquetebol: G10% - no qual 10% do desempenho do pré-teste foram acrescidos para o estabele-cimento da meta, e G30%, no qual 30% foi acrescido para estabelecimento da meta. Após a última fa-se, os indivíduos responderam a um questionário de avaliação do comprometimento a meta. A expec-tativa era que o grupo com maior percentagem no estabelecimento da meta iria demonstrar piores re-sultados e menor comprometimento com a meta estabelecida devido a dificuldade imposta. As análi-ses mostraram que apesar da melhora significativa de ambos os grupos, os diferentes percentuais no estabelecimento de metas foram similares na mudança do desempenho. Entretanto, o acréscimo de 10% ao desempenho no pré teste permitiu maior comprometimento com a meta

Movie S2 from Unique perceptuomotor control of stone hammer in wild monkeys

A representative bearded capuchin monkey, Teimoso (body mass = 3.6 kg), is striking an intact piaçava nut with a 1.48 kg hammer

Table S1 - S3 from Unique perceptuomotor control of stone hammers in wild monkeys

We analysed the patterns of coordination of striking movement and perceptuomotor control of stone hammers in wild bearded capuchin monkeys, <i>Sapajus libidinosus</i> as they cracked open palm nut using hammers of different mass, a habitual behaviour in our study population. We aimed to determine why these monkeys cannot produce conchoidally fractured flakes as do contemporary human knappers or as did prehistoric hominin knappers. We found that the monkeys altered their patterns of coordination of movement to accommodate changes in hammer mass. By altering their patterns of coordination, the monkeys kept the strike's amplitude and the hammer's velocity at impact constant with respect to hammer mass. In doing so, the hammer's kinetic energy at impact—which determines the propagation of a fracture/crack in a nut—varied across hammers of different mass. The monkeys did not control the hammer's kinetic energy at impact, the key parameter a perceiver-actor should control while knapping stones. These findings support the hypothesis that the perceptuomotor control of stone hammers in wild bearded capuchin monkeys is inadequate to produce conchoidally fractured flakes by knapping stones, as do humans

Movie S1 from Unique perceptuomotor control of stone hammer in wild monkeys

A representative bearded capuchin monkey, Teimoso (body mass = 3.6 kg), is striking an intact piaçava nut with a 1.01 kg hammer

Movie S3 from Unique perceptuomotor control of stone hammers in wild monkeys

A representative bearded capuchin monkey, Teimoso (body mass = 3.6 kg), is striking an intact piaçava nut with a 1.91 kg hammer