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BACKGROUND: Early sport specialization has increased its popularity mostly based on the deliberate practice theory premises. In this study, we examined the influence of the age of onset of deliberate basketball practice on body size, functional performance (countermovement jump, line drill and yo-yo intermittent recovery level 1), motivation for achievement and competitiveness, motivation for deliberate practice and sources of enjoyment among young Brazilian basketball players. In addition, we adjusted for the influence of gender, age group, maturity status and state basketball federation on the outcomes. METHODS: The sample included 120 female and 201 male adolescent basketball players aged 14.0 (1.7) years, on average. We grouped players by the age of onset of deliberate basketball practice as related to biologic maturation milestones (pre-puberty deliberate practice onset, mid-puberty deliberate practice onset and late-puberty deliberate practice onset). RESULTS: There was no substantial variation among contrasting players by the onset of deliberate practice in all of the outcomes. Adjusting for gender, male players with late-puberty deliberate practice onset had better functional performance than players with pre- and mid-puberty onset of practice. Females players with late-puberty deliberate practice onset had slightly worst functional performance than players with pre- and mid-puberty onset of practice. CONCLUSIONS: Early deliberate basketball practice does not appear to provide an advantage for the development of physiological functions. Likewise, enjoyment, motivation for deliberate practice and motivation for achievement and competition do not appear to be negatively influenced by early deliberate basketball practice. The debate about the relationship between time spent in deliberate practice and performance development in young athletes will need to emphasize the coaching pedagogical quality and the training environment and account for informal practice and deliberate play.

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The purpose of this study was to examine the variation in accumulated basketball training experience, body size, functional performance, deliberate practice motivation, achievement and competitiveness motivation and sources of enjoyment among young female basketball players, partitioning the potential variation by individuals´ biological characteristics (menarche status) and contextual characteristics (competitive age group and competitive level). We considered 114 adolescent female basketball players aged 14.3 (1.8) years. We used multilevel regression and poststratification estimations. The adolescent female basketball players selected for state-level had more accumulated experience, were taller and with better functional performance. Conditional on the data, youth female coaches tend to value (probably overvalue) size and function when selecting/promoting players, even at early age groups, likely contributing to an overrepresentation of early maturing girls in at early age groups. Players from club- and state-level were similarly highly motivated for deliberate practice and to achievement. Only for competitiveness, state-level players had higher values than club level players. The sources of enjoyment were influenced by context (competitive levels) for self-referenced competencies and others-referenced competencies. Structured programs of training and competition in youth female basketball provide a nurturing environment for the development of players´ engagement and commitment to training and excellence attainment.

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Using an interdisciplinary approach, we examined the baseline variation in biological maturity status, training experience, body size, functional capacities (Line Drill test and Yo-Yo Intermittent Recovery level 1 test) and motivation for achievement, competitiveness and deliberate practice of youth basketball players according to their participation status in the sport two years after assessment. Fifty-seven players were considered (10.5 to 15.5 years). Two years later we ascertained whether players discontinued participation (dropout), or remained playing engaged within a structured basketball training program. Taller adolescent players were more likely to be selected/promoted in youth basketball regardless of their lower functional capacity. Achievement and competitiveness motivation (will to excel and competitiveness) were related to dropping out or persisting in this sample of youth basketball players. Overall, there is a need to consider the interaction between physical growth, biological maturation, functional capacities and behavioural characteristics, specifically among players on the path to sport expertise.

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Background and Objectives: This study considered the use of a generalized additive multilevel model to describe the joint-angle-specific functional hamstring to quadriceps ratio (H:Q ratio) in the knee, using all of the available truly isokinetic data within the range. Materials and Methods: Thirty healthy male basketball players aged 15.0 (1.4) years (average stature = 180.0 cm, SD = 11.1 cm; average body mass = 71.2, SD = 14.9 kg) years were considered. All players considered had no history of lower extremity musculoskeletal injury at the time of testing or during the 6 months before testing, and had been engaged in formal basketball training and competition for 5.9 (2.4) years. Moments of force of the reciprocal concentric and eccentric muscular actions for the knee extensors and flexors assessed by isokinetic dynamometry at 60°âˆ™s-1 were used. Results: Maximum moments of force were attained at different angle positions for knee extension. For knee flexion, it was apparent that there was an ability to maintain high levels of moment of force between 30° and 60° in the concentric muscular action, corresponding to the concentric action of the hamstrings. However, for the eccentric knee flexion, corresponding to the quadriceps action, there was a marked peak of moment of force at about 55°. The functional H:Q ratio for the knee extension was non-linear, remaining higher than 1.0 (i.e., point of equality) from the beginning of the extension until approximately 40° of the knee extension, leveling off below the point of equality thereafter. On average, the functional H:Q ratio for the knee flexion did not attain 1.0 across the range of motion. The functional H:Q ratio for the knee in the present sample peaked at 20° and 80°, declining between these angle positions to below 0.50 at about 0.54. Conclusions: Estimating the form of the non-linear relationship on-the-fly using a generalized additive multilevel model provides joint-angle-specific curves and joint-angle-specific functional H:Q ratio patterns, allowing the identification and monitoring of strength development, with potential implications for injury and performance.

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Background: The interpretation of young athletes' performance during pubertal years is important to support coaches' decisions, as performance may be erroneously interpreted due to the misalignment between chronological age (CA), biological age (BA) and sport age (SA). Aim: Using a Bayesian multilevel approach, the variation in longitudinal changes in performance was examined considering the influence of CA, BA (age at menarche), SA, body size, and exposure to training among female basketball players. Method: The study had a mixed-longitudinal design. Thirty eight female basketball players (aged 13.38 ± 1.25 years at baseline) were measured three times per season. CA, BA and SA were obtained. Anthropometric and functional measures: countermovement jump, Line drill (LD), Yo-Yo (Yo-Yo IR1). Based on the sum of the z-scores, an index of overall performance was estimated. The effects of training on longitudinal changes in performance were modeled. Results: A decrease in the rate of improvements was apparent at about 14 years of age. When aligned for BA, the slowing of the rate of improvements is apparent about 2 years after menarche for LD. For countermovement jump longitudinal changes, when performance was aligned for BA improvements became linear. For Yo-Yo IR1 and performance index, both indicators showed a linear trend of improvement when aligned for CA and BA, separately. Older players showed higher rates of improvement for Yo-Yo IR1 and performance index from pre-season to end-season. When considering performance changes aligned for BA it was apparent an improvement of performance as players became biologically mature. Conclusions and Implications: The alignment of CA with BA and SA provides important information for coaches. Human growth follows a genetically determined pattern, despite variation in both tempo and timing. When the effects of maturation reach their end, all the girls went through the same process. Hence, there is no need to artificially manipulate youth competitions in order to accelerate gains that sooner or later reach their peak and tend to flat their improvement curve.

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Abstract The present study examined the changes in developmental assets among young basketball players during a 4-month competitive period, accounting for variation by age group. Additionally, we examined the age-related variation on developmental assets. Sixty-five adolescent basketball players aged between 9.5 to 17.3 years were considered. We used the Portuguese version of the Developmental Assets Profile Questionnaire. Multilevel modeling was used to estimate the magnitude of changes on developmental assets across the 4-month competitive season, as well as aligning assets scores by chronological age. Positive values and positive identity scores were substantially increased after the 4-month competitive sample. The other assets scores showed no variation across the competitive 4-month competitive season, independent of age group. There was a trend of linear decrease in developmental assets as the adolescent players got older. For positive values, there was a non-linear trend with a higher decrease rate between about 10 to 14 years, levelling off thereafter. Developmental assets did not appear to be influenced by exposure to a period of organized training and competition among adolescent basketball players. Hence, the observed decrease on developmental assets when aligning by age may reflect the influence of contextual and cultural environments of practice. This is of particularly interest for positive values, which refer to school engagement or and social justice, qualities that are not sport-specific but assume a key and importance position in sport participation for a positive role in youth development.

Resumo O presente estudo examinou as mudanças nos ativos de desenvolvimento entre jovens jogadores de basquetebol durante um período competitivo de 4 meses, considerando a variação por faixa etária. Adicionalmente, examinou-se a variação da idade no desenvolvimento dos Ativos. Participaram deste estudo 65 adolescentes jogadores de basquetebol com idade entre 9.5 a 17.3 anos. Utilizou-se a versão em português do Questionário de Perfil de Ativos de Desenvolvimento. O modelo multinível foi usado para estimar a magnitude das mudanças nos ativos de desenvolvimento, bem como alinhar as pontuações dos ativos por idade cronológica. Os valores de valores positivos e de identidade positiva foram aumentados após 4 meses competitivos. Já os outros não mostraram variação na mesma temporada, independente da faixa etária. Houve uma tendência de diminuição linear nos ativos de desenvolvimento à medida que os adolescentes se tornaram mais velhos. Para os valores positivos, houve uma tendência não linear com uma taxa de decréscimo mais alta entre cerca de 10 a 14 anos, nivelando-se depois disso. Os ativos de desenvolvimento não parecem ser influenciados pela exposição a um período de competição entre jogadores de basquete adolescentes. Assim, a diminuição nos ativos de desenvolvimento ao alinhar pela idade pode refletir a influência dos contextos culturais e de prática. Isto é particularmente interessante para valores positivos, que se referem ao envolvimento escolar ou à justiça social, qualidades que não são específicas do esporte, mas que assumem uma posição chave e importante na participação esportiva para desenvolvimento positivo da juventude.

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Abstract Considering agility is a prerequisite for basketball performance and several agility tests have been used during the pre-draft assessment of the National Basketball Association (NBA), the aimed of this study was to examine the associations between pre-draft athletes´ performance scores in NBA draft combine testing protocol. The performance of 480 athletes invited to the NBA pre-draft assessment from 2010 to 2017 was considered. Tests in the NBA Draft Combine considered in this study included the Shuttle Run Test, Lane Agility Test, Sprint Test, and Jump Test (standing vertical leap). Zero order correlations were calculated to examine the associations between performance tests by fitting Bayesian linear regression models. Among running testing, both Shuttle Run Test [r=0.45, 95% confidence interval (CI) 0.34 to 0.56) and Sprint Test (r=0.45, 95% CI 0.37 to 0.54) were moderately associated with the Lane Agility Test. The association between the Sprint Test and Shuttle Run Test was moderate at best (r=0.27, 95% CI 0.16 to 0.38). Correlations between Jump Test and running tests were moderate to large, ranging from -0.51 to -0.19 (Lane Agility Test: r=-0.33, 95% CI -0.42 to -0.24; Shuttle Run Test: r=-0.19, 95% CI -0.31 to -0.07; Sprint Test: r=-0.51, 95% CI -0.59 to -0.43). As a conclusion, we found a moderate to large correlations between the tests performance of the NBA Draft Combine, implying that the overall procedures may provide in part overlapping information about basketball maximal short term performance.

Resumo O objetivo deste estudo foi examinar as associações entre os escores de desempenho dos atletas no Pre-Draft Combine da NBA. Foram examinados os desempenhos de 480 atletas nas avaliações do Pre-draft Combine da NBA de 2010 a 2017. Os testes do Draft Combine considerados incluíram o Shuttle Run Test, o Lane Agility Test, o Sprint Test e o Jump Test (salto vertical em pé). Correlações de ordem zero foram calculadas para examinar as associações entre os testes de desempenho através da adequação de modelos de regressão linear Bayesiana. Entre os testes de corrida, tanto o teste Shuttle Run (r = 0,45, intervalo de confiança (IC) de 95% 0,34 a 0,56) e teste de Sprint (r = 0,45, IC 95% 0,37 a 0,54) foram moderadamente associados com o Teste Lane Agility. A associação entre o Sprint Test e o Shuttle Run Test foi de moderada para alta (r = 0,27, IC 95% 0,16 a 0,38). As correlações entre o Teste de Salto e os testes de corrida foram de moderada a grande, variando de -0,51 a -0,19 (Lane Agility Test: r = -0,33, IC 95% -0,42 a -0,24; Teste Shuttle Run: r = -0,19, IC 95% -0,31 a -0,07; Teste de Sprint: r = -0,51, IC 95% -0,59 a -0,43). Assim, foi verificado uma correlação de moderada a grande entre o desempenho dos testes do Draft Combine da NBA, o que indica que os procedimentos gerais podem fornecer, parcialmente, informações sobrepostas sobre o desempenho máximo de curto prazo do basquetebol.

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Em cães, a comprovação da real viabilidade da pneumonectomia direita, bem como, o estudo das complicações resultantes deste procedimento cirúrgico, tornam-se importantes diante da pequena quantidade de estudos na literatura específicos sobre pneumonectomia nesta espécie. O objetivo deste trabalho foi realizar um estudo experimental para avaliar a viabilidade da pneumonectomia direita em cães, através da avaliação paramétrica, hemogasométrica e radiográfica Foram utilizados 10 cães adultos, sadios, machos e fêmeas sem raça definida, pesando entre 13 e 32 kg. Todos os cães foram submetidos à intubação seletiva e toracotomia direita no 5º espaço intercostal, onde foi realizada a pneumonectomia. Foi realizado estudo temporal aos 7, 30 e 60 dias de pós-operatório, onde foi feito avaliação radiográfica, bem como, avaliação paramétrica e hemogasométrica (antes da indução anestésica, 1 hora após extubação, 48 horas, 7, 30 e 60 dias após o procedimento cirúrgico), con,siderados importantes para avaliar as possíveis complicações relacionadas com a técnica anestésica, cirúrgica, assim como, as complicações resultantes deste procedimento cirúrgico. Os resultados encontrados foram analisados estatisticamente. Apesar das alterações dos índices paramétricos e hemogasométricos, todos os cães apresentaram compensação das trocas gasosas após retirada de 57 por cento do volume pulmonar. Na avaliação radiográfica, observamos que a expansão do pulmão remanescente causou deslocamento do coração e pulmão para hemitórax direito. Concluiu-se que a realização da pneumonectomia direita é plenamente viável no cão, permitindo evolução paramétrica, hemogasométrica e radiográfica satisfatória em todos os cães.(AU)

In dogs, the evidence of viability of the right pneumonectomy, as well as the study of complications resulting from surgical procedure, are very important regarding the few specific studies made on the pneumonectomy in this animal species. The objective of this project was to carry out an experimental study to evaluate the viability of the right pneumonectomy in dogs through parametric, hemogasometric and radiographic evaluation. Ten adult healthy mongrel dogs, males and females, weighing 13-32 kg, were used. The dogs were submitted to selective intubation and right thoracotomy at the 5th intercostal space, where the pneumonectomy was performed. A radiografic evaluation was made on days 7, 30 and 60 after the surgery, as well as parametric and hemogasometric evaluations were done (before anesthetic induction, 1 hour after extubation, 48 hours and on days 7, 30 and 60 after the surgical procedure), considered important to evaluate possible complications due to the anesthetic and surgical techniques, as well as complications resulting from these procedures. The results were analyzed statistically. Besides the parametric and hemogasometric alterations, all dogs showed compensation for the gaseous exchanges after removing 57 percent of the pulmonary volume. Regarding the radiographic evaluation, it could be observed that the expansion of the remaining lung caused heart and lung displacement into the right hemithorax. It can be concluded that the right pneumonectomy is completely feasible in dogs, allowing a parametric, hemogasometric and radiographic satisfactory evaluation in all the animals.(AU)

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Em cães, a comprovação da real viabilidade da pneumonectomia direita, bem como, o estudo das complicações resultantes deste procedimento cirúrgico, tornam-se importantes diante da pequena quantidade de estudos na literatura específicos sobre pneumonectomia nesta espécie. O objetivo deste trabalho foi realizar um estudo experimental para avaliar a viabilidade da pneumonectomia direita em cães, através da avaliação paramétrica, hemogasométrica e radiográfica Foram utilizados 10 cães adultos, sadios, machos e fêmeas sem raça definida, pesando entre 13 e 32 kg. Todos os cães foram submetidos à intubação seletiva e toracotomia direita no 5º espaço intercostal, onde foi realizada a pneumonectomia. Foi realizado estudo temporal aos 7, 30 e 60 dias de pós-operatório, onde foi feito avaliação radiográfica, bem como, avaliação paramétrica e hemogasométrica (antes da indução anestésica, 1 hora após extubação, 48 horas, 7, 30 e 60 dias após o procedimento cirúrgico), con,siderados importantes para avaliar as possíveis complicações relacionadas com a técnica anestésica, cirúrgica, assim como, as complicações resultantes deste procedimento cirúrgico. Os resultados encontrados foram analisados estatisticamente. Apesar das alterações dos índices paramétricos e hemogasométricos, todos os cães apresentaram compensação das trocas gasosas após retirada de 57 por cento do volume pulmonar. Na avaliação radiográfica, observamos que a expansão do pulmão remanescente causou deslocamento do coração e pulmão para hemitórax direito. Concluiu-se que a realização da pneumonectomia direita é plenamente viável no cão, permitindo evolução paramétrica, hemogasométrica e radiográfica satisfatória em todos os cães.

In dogs, the evidence of viability of the right pneumonectomy, as well as the study of complications resulting from surgical procedure, are very important regarding the few specific studies made on the pneumonectomy in this animal species. The objective of this project was to carry out an experimental study to evaluate the viability of the right pneumonectomy in dogs through parametric, hemogasometric and radiographic evaluation. Ten adult healthy mongrel dogs, males and females, weighing 13-32 kg, were used. The dogs were submitted to selective intubation and right thoracotomy at the 5th intercostal space, where the pneumonectomy was performed. A radiografic evaluation was made on days 7, 30 and 60 after the surgery, as well as parametric and hemogasometric evaluations were done (before anesthetic induction, 1 hour after extubation, 48 hours and on days 7, 30 and 60 after the surgical procedure), considered important to evaluate possible complications due to the anesthetic and surgical techniques, as well as complications resulting from these procedures. The results were analyzed statistically. Besides the parametric and hemogasometric alterations, all dogs showed compensation for the gaseous exchanges after removing 57 percent of the pulmonary volume. Regarding the radiographic evaluation, it could be observed that the expansion of the remaining lung caused heart and lung displacement into the right hemithorax. It can be concluded that the right pneumonectomy is completely feasible in dogs, allowing a parametric, hemogasometric and radiographic satisfactory evaluation in all the animals.

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