La biomecánica aplicada a la técnica de pitcheo en lanzadores de béisbol

El deporte como fenómeno social, se desarrolla en la actualidad simultáneamente con los adelantos de la ciencia y la tecnología; en este contexto, juega un papel importante la biomecánica que asegura las bases para un verdadero entrenamiento técnico, de ahí que el trabajo está dirigido al uso de la biomecánica en la técnica de pitcheo. Para dar respuesta a esta temática se concibe como objetivo aplicar estudios biomecánicos a la técnica de pitcheo en los lanzadores del equipo de béisbol La Isla de la Juventud. Se utilizaron como métodos el análisis de documentos, la revisión bibliográfica, la observación científica, la entrevista y la técnica del análisis de video con ayuda de un Dron; ello permitió medir magnitudes y valorar el comportamiento de las características que poseen los movimientos ejecutados por los lanzadores objeto de estudio. También, se emplearon dos técnicas de mediciones, una a través de la filmación y otra por procesamiento cinemático con el uso de los softwares como Tracker y Kinovea. La muestra estuvo conformada por ocho sujetos, distribuidos en tres atletas, dos entrenadores y tres investigadores; esto permitió determinar las características de la distancia de paso, ángulo que forma el brazo de lanzar con respecto a la cabeza, altura de la pelota y la velocidad de la pelota ejecutados por los lanzadores investigados.

O esporte, como fenômeno social, está se desenvolvendo simultaneamente com os avanços da ciência e da tecnologia; nesse contexto, a biomecânica desempenha um papel importante para garantir a base de um verdadeiro treinamento técnico, portanto, o trabalho visa ao uso da biomecânica na técnica de arremesso. Para responder a essa questão, o objetivo foi aplicar estudos biomecânicos à técnica de arremesso nos arremessadores do time de beisebol La Isla de la Juventud. Os métodos utilizados foram a análise de documentos, a revisão bibliográfica, a observação científica, a entrevista e a técnica de análise de vídeo com a ajuda de um drone, o que permitiu medir as magnitudes e avaliar o comportamento das características dos movimentos executados pelos arremessadores em estudo. Além disso, foram utilizadas duas técnicas de medição, uma por meio de filmagem e outra por meio de processamento cinemático com o uso de softwares como o Tracker e o Kinovea. A amostra foi composta por oito sujeitos, distribuídos em três atletas, dois técnicos e três pesquisadores, o que nos permitiu determinar as características da distância de arremesso, do ângulo do braço de arremesso em relação à cabeça, da altura da bola e da velocidade da bola executada pelos arremessadores investigados.

Sport as a social phenomenon, currently develops simultaneously with the advances of science and technology; in this context, biomechanics plays an important role that ensures the bases for true technical training; hence the work is directed to the use of biomechanics in throwing technique. To respond to this issue, the objective is to apply biomechanical studies to the throwing technique in the throwers of the La Isla de la Juventud baseball team. Document analysis, bibliographic review, scientific observation, interview and the technique of video analysis with the help of a drone were used as methods; this made it possible to measure magnitudes and assess the behavior of the characteristics of the movements executed by the throwers under study. Also, two measurement techniques were used, one through filming and the other by kinematic processing with the use of software such as Tracker and Kinovea. The sample consisted of eight subjects, divided into three athletes, two coaches and three researchers; this allowed to determine the characteristics of the throw distance, the angle formed by the throwing arm with respect to the head, the height of the ball, and the speed of the ball executed by the investigated throwers.

Concepción teórica para favorecer la transferencia de la rapidez de movimientos técnicos en el lanzamiento del martillo

El presente artículo se realizó a partir de detectar insuficiencias teórico-metodológicas y prácticas en el proceso de preparación técnica del lanzador de martillo categoría escolar; por tal razón, se propuso como objetivo general elaborar una concepción teórica para favorecer el entrenamiento en la transferencia de la rapidez de movimientos técnicos de los giros al instante final del lanzamiento del martillo, en atletas categoría escolar de la Eide "Pedro Batista Fonseca" de la provincia de Granma. Para el logro del objetivo antes expuesto se emplearon métodos de la investigación científica como los teóricos, el análisis y síntesis, el hipotético-deductivo y el sistémico estructural funcional; dentro de los empíricos, el análisis de documentos, la observación y la medición y como método matemático-estadístico la estadística descriptiva, además, se utilizó como técnica de investigación la entrevista. La propuesta permitió la sistematización de aquellos elementos relacionados directamente con la transferencia en el deporte y el proceso de entrenamiento del lanzador de martillo; de tal manera se previó, con su aplicación, el perfeccionamiento técnico de los atletas implicados en la investigación, así como un incremento en su rendimiento y resultados deportivos.

O presente artigo foi realizado a partir da detecção de insuficiências teórico-metodológicas e práticas no processo de preparação técnica do arremessador de martelos da categoria escola; por esta razão, foi proposto como objetivo geral elaborar uma concepção teórica para favorecer o treinamento na transferência da velocidade dos movimentos técnicos das voltas para o instante final do arremesso do martelo, na categoria escola atletas do Eide "Pedro Batista Fonseca" da província de Granma. Para alcançar o objetivo acima mencionado, foram utilizados métodos de pesquisa científica, tais como métodos teóricos, de análise e síntese, hipotéticos-dedutivos e estruturais-funcionais sistêmicos; dentro dos métodos empíricos, análise de documentos, observação e medição, e estatística descritiva como método matemático-estatístico; além disso, a entrevista foi utilizada como técnica de pesquisa. A proposta permitiu a sistematização daqueles elementos diretamente relacionados com a transferência no esporte e o processo de treinamento do martelo lançador; de tal forma que, com sua aplicação, foi previsto o aperfeiçoamento técnico dos atletas envolvidos na pesquisa, bem como um aumento de seu desempenho e resultados esportivos.

The present article was carried out from the detection of theoretical-methodological and practical insufficiencies in the process of technical preparation of the school category hammer thrower; For this reason, it was proposed as a general objective to develop a theoretical conception to favor training in the transfer of the speed of technical movements of the turns to the final moment of the hammer throw, in school category athletes of the Eide" Pedro Batista Fonseca" of Granma province. To achieve the aforementioned objective, scientific research methods such as theoretical, analysis and synthesis, hypothetical-deductive and structural-functional systemic were used; within the empirical, the analysis of documents, observation and measurement and as a mathematical-statistical method descriptive statistics, in addition, the interview was used as a research technique. The proposal allowed the systematization of those elements directly related to the transfer in sport and the training process of the hammer thrower; In this way, with its application, the technical improvement of the athletes involved in the research was foreseen, as well as an increase in their performance and sports results.

Fiabilidad y estabilidad del gesto de diferentes variantes de lanzamiento de balonmano / Reliability and Stability of the Gesture of Different Variants of drowing of Handball

Resumen El estudio tiene como propósito analizar la fiabilidad de la prueba de 8 lanzamientos de 3 diferentes variantes de lanzamientos de balonmano en estudiantado universitario. 33 varones, 20 ±1,9 años; peso 72,39±8,9 kg; altura 176,75 ±6,07 cm; IMC 23,14±2,3. Los sujetos participantes fueron evaluados en 2 sesiones separadas entre sí por un lapso de una semana. Ejecutaron lanzamientos hasta quedar registrados 8 mediciones en cada una de las pruebas, lanzamientos inespecíficos, en apoyo y en carrera con 3 pasos, se registró la velocidad de lanzamiento con un radar posterior a la portería. La fiabilidad del promedio de las puntuaciones del test de 8 medidas entre la primera sesión y la segunda con una prueba test-retest, se obtuvieron los siguientes resultados: en el lanzamiento inespecífico se obtuvo un ICC= (0,86) entre el 95% de confianza, un de CV= (7,43%) y un ES= (0,08). Para el lanzamiento con apoyo se obtuvo un ICC= (0,94) al 95 % de confianza, un de CV= (4,71 %) y un ES= (-0,09). Para el lanzamiento con carrera se obtuvo un ICC= (0,96) al 95 % de confianza, un de CV= (4,00 %) y un ES= (0,05). Este estudio ha demostrado que la prueba de 8 lanzamientos y las 3 variantes es una medida de rendimiento confiable y estable para estudiantes de nivel universitario sin experiencia en el balonmano, en relación con las variables del lanzamiento, las 3 fueron fiables, solo la variable inespecífica fue menor en comparación al lanzamiento con apoyo y con carrera.

Abstract This study aims to analyze the reliability of the test of 8 throws of 3 different variants of handball throws in university students. The participants were 33 males, 20 ± 1.9 years; weight 72.39 ± 8.9 kg; height 176.75 ± 6.07 cm; BMI 23.14 ± 2.3. They were evaluated in 2 sessions separated from each other by a period of one week. The participants executed throws until 8 measurements were recorded in each of the tests, unspecific throws, in support and in the race with 3 steps; the launch speed was recorded with a radar behind the goal. The reliability of the average of the test scores of 8 measurements between the first session and the second was measured with a test-retest test. The following results were obtained: in the nonspecific launch, an ICC= (0.86) was obtained between 95% of confidence, one of CV= (7.43%) and one ES = (0.08). For the toss with support, an ICC = (0.94) was obtained at 95% confidence, one of CV = (4.71%) and an ES = (-0.09). For the running throw, an ICC = (0.96) was obtained at 95% confidence, one of CV = (4.00%) and one ES = (0.05). This study has shown that the test of 8 throws and the 3 variants is a reliable and stable performance measure for university-level students without experience in handball; in relation to the throw variables, all 3 were reliable. Only the nonspecific variable was lower compared to the supported and running pitch.

Resumo O estudo tem como objetivo analisar a confiabilidade do teste de 8 arremessos de 3 variantes diferentes de arremessos de handebol em estudantes universitários. 33 homens, 20 ±1,9 anos; peso 72,39±8,9 kg; altura 176,75 ±6,07 cm; IMC 23,14±2,3. Os participantes foram testados em 2 sessões separadas por um lapso de 1 semana. Os participantes executaram arremessos até poder registrar 8 medições em cada um dos testes, arremessos não específicos, com apoio e correndo com 3 passos. A velocidade de arremesso foi registrada com um radar pós-gol. A confiabilidade da média dos resultados dos testes de 8 medições entre a primeira sessão e a segunda com um teste de retorno, deu os seguintes resultados: no teste de lançamento não específico, foi obtido um ICC= (0,86) com 95% de confiança, um CV= (7,43%) e um ES= (0,08). Para o lançamento apoiado obtivemos um ICC= (0,94) a 95% de confiança, um CV= (4,71%) e um ES= (-0,09). Para o arremesso de corrida obtivemos um ICC= (0,96) a 95% de confiança, um CV= (4,00%) e um ES= (0,05). Este estudo mostrou que o teste de 8 lances e as 3 variantes é uma medida de desempenho confiável e estável para estudantes universitários sem experiência em handebol. Em relação às variáveis de arremesso, todas as 3 foram confiáveis, apenas a variável não específica foi menor em comparação com o arremesso com suporte e com corrida.

TO FIND CORRELATION OF CORE STRENGTH AND THORACIC ROTATION WITH SPEED OF THROWING IN CRICKETERS

Cricket is one of the most popular games which is played all over the world and its popularity has ever been increasing in the last decade. Fielding is an important dimension of the game as is batting and bowling. With the game being so fast with the introduction of 20 overs game fielding has had an increased demand in the sport. Throwing is considered one of the major and main activities of fielding. Throwing motions involve moving objects spatially using body segments, in particular, hand and arm segments, which can be classified into overarm throws, sidearm throws and underarm throws and divided into throwing objects quickly, accurately and far away. Aim of this study was to find The Correlation of Core Strength and Thoracic Rotation with Speed of Throwing in Cricketers. 31 Cricketers were assessed for their core strength with side rotational medicine ball throws and distance measured, Thoracic rotation in lumbar locked sitting position and measuring with universal goniometer and speed of throws with a BUSHNELL Speed gun. Results of this study showed that Core Strength and Speed of Throws showed a positive, strong and significant correlation whereas Thoracic Rotation and Speed of Throws also showed a positive and significant correlation. Core Strength showed greater clinical and statistical correlation with Speed of Throws than Thoracic Rotation. This study will not only help in preventing throwing injuries but also will help to train and enhance throwing abilities and overall performance

Correlation of resting scapular position and functional throwing performance index among amateur basketball players: An observational study

Background: Scapular dyskinesis is prevalent in 54.5% of overhead athletes. Scapular dyskinesis is abnormal positioning of the scapula over the thorax and also abnormal motions of the scapula. Any alterations to the normal scapular position may alter the accuracy of striking and serving in basketball players. This study aims to find out the relation between the resting scapular position and the throwing accuracy of players. Results: The research suggests that there is a moderate correlation present between the resting scapular position and the throwing accuracy of the players. Conclusion: In this study, results state that the resting position of the scapula plays an important role in power generation and biomechanics of throwing in overhead athletes affecting the throwing accuracy of players.

Effect of somatotype on the general physical fitness tests and throwing velocity on handball

Abstract Aim: The study aimed to investigate the effects of the somatotype components on handball. Methods: The sample consisted of 60 elite junior handball players. Somatotype was evaluated using the Heath & Carter method. The kinetic performance trials of the handball athletes were running speed performance over 5 m 10 m and 20 m sprints, sit and reach, standing long jump (SLJ), ball velocity, and maximum aerobic power. For the data analyses, we used Pearson correlation and multiple linear regression. Results: The endomorphic component correlated positive with all three sprint times (5 m, 10 m και 30 m sprints) (r = 0.315, p = 0.014; r = 0.367, p = 0.004; r = 0.358, p = 0.005 respectively) while negative with SLJ (r = -0.418, p = 0.001) και maximum aerobic power (r = -0.322, p = 0.012). The mesomorphic component had a positive correlation with ball velocity (r = 0.260, p = 0.045) and negative relation with SLJ (r = -0.261, p = 0.044). The ectomorphic component exhibited a negative correlation only with ball velocity (r = -0.260, p = 0.045). The ordinary least square regression models found that endomorphy and ectomorphy were prognostic factors and predicted worse performance in all of the examined motor performance indices except ball velocity and 5 m sprint, while mesomorphy was a predictor of worse performance in SLJ. Conclusions: In conclusion, according to the findings of this study, somatotype components play an important role in performance-related parameters.

Efecto de un programa de realidad virtual para mejorar la estabilidad de tronco en lanzadores de bala y jabalina paralímpicos. Un estudio de casos / Effect of a virtual reality program to improve trunk stability in Paralympic shot put and javelin throwers. A case study

Introducción: El deporte paralímpico se originó como parte de procesos de re-habilitación para personas que tuvieran discapacidad. Durante la ejecución de las disciplinas paralímpicas el control motor en la región del tronco y en especial del abdomen es de gran importancia para prevenir lesiones y mejorar el registro de la marca deportiva. Son muchas las herramientas utilizadas por los entrenadores de-portivos para mejorar la fuerza muscular y por consiguiente la estabilidad de tronco, buscando disminuir el riesgo en el ámbito deportivo. Sin embargo, las investigaciones sobre el uso de realidad virtual, junto con plataformas de estabilometría para el en-trenamiento de deportistas paralímpicos con lesiones físicas, son escasas.Objetivo: Establecer el efecto de un programa de entrenamiento del tronco apoya-do en realidad virtual en deportistas de alto rendimiento paralímpicos, lanzadores de bala y jabalina con lesiones físicas y que compiten en sillas de lanzamiento. Materiales y método: La investigación fue diseñada como un estudio cuasiex-perimental intrasujeto. Se evaluaron cinco sujetos deportistas paralímpicos de alto rendimiento con discapacidad física. Se empleó un software de realidad virtual que incluye patrones y juegos lúdicos ajustables en tiempo e intensidad y una platafor-ma de bipedestación dinámico como parte del equipo de intervención, ajustable al paciente, que permite reeducar el equilibrio, la propiocepción, fortalecer y lograr el control del tronco. Las variables de análisis fueron el nivel del desplazamiento ante-roposterior y lateral del tronco y los cambios en el volumen de acción. Se realizó una evaluación inicial, una intervención que duró de seis semanas y la evaluación final. Resultados: En las evaluaciones iniciales de todos los atletas se observó una ten-dencia al desplazamiento en sentido posterior. En la evaluación final, los rangos de desplazamiento aumentan en casi todos los sujetos con excepción del sujeto 5, cuyos valores permanecen casi estables tanto en las evaluaciones iniciales como las finales. La diferencia en el desplazamiento entre la prueba inicial y final en promedio de los participantes fue de 6.26 grados. Conclusiones: los resultados positivos del entrenamiento del tronco apoyado en realidad virtual para los participantes constituyen un aporte al conocimiento sobre el tema y abren la posibilidad de incluir esta tecnología en protocolos de entrenamiento en deporte paralímpico.

Introduction: Paralympic sport originated as part of rehabilitation processes for people with disabilities. During the execution of Paralympic disciplines, motor con-trol in the trunk region and especially in the abdomen is of great importance to prevent injuries and improve the registration of the sports record. There are many tools used by sports coaches to improve muscle strength and therefore trunk stability to reduce the risk in the sports field. However, research on the use of virtual reality along with stabilometry platforms for the training of Paralympic athletes with phys-ical injuries are scarce.Objective: To establish the effect of a trunk training program supported by virtual reality in high performance Paralympic athletes, shot put and javelin throwers with physical injuries who compete in throwing frames. Materials and method: The research was designed as an intrasubject quasi-ex-perimental study. Five high-performance Paralympic athletes with physical disabili-ties were evaluated. A virtual reality software that includes patterns and playful games adjustable in time and intensity and a dynamic standing platform were used as part of the intervention equipment, adjustable to the patient, which allows reeducating balance, proprioception, strengthening, and achieving trunk control. The variables of analysis were the level of anteroposterior and lateral displacement of the trunk and changes in the volume of action. An initial evaluation, an intervention that lasted six weeks, and a final evaluation were carried out. Results: In the initial evaluations of all athletes, a tendency towards posterior dis-placement was observed. In the final evaluation, the displacement ranges increase in almost all subjects except for subject 5, which showed values that remain almost sta-ble in both the initial and final evaluations. The difference in displacement between the initial and final test on average of the participants was 6.26 degrees. Conclusions: the positive results of trunk training supported by virtual reality for the participants constitute a contribution to the knowledge on the subject and open the possibility of including this technology in training protocols in Paralympic sports.

A feasibility study of the incidence and symptoms of the throwing yips in college baseball players / 体力科学

The yips represent a disorder that makes it challenging for an individual to perform automatic and coordinated movements in sports activities. The cause of the yips is not sufficiently clarified, and limited information is available regarding throwing yips in baseball. Therefore, this study was designed to clarify the incidence and characteristics of the throwing yips among college baseball players. Total 107 players of the college baseball team participated in the study and completed the questionnaire by answering questions about their experience of the yips (loss of control to throw the ball accurately for more than 1 month), the symptom intensity, and changes observed in the symptoms in different situations. The 47.1% of players met the definition of throwing yips. The symptoms of the yips were more pronounced with short-distances and low intensity of throwing. Moreover, there were various subjective symptoms, such as the issue about co-contraction of the upper limb, sensory function, body ownership, and movement planning. Various physical symptoms associated with throwing yips suggest that the yips are not only a disorder of motor skills, but result from movement disorders. The present results show that the occurrence of the yips depends on the throwing condition; this finding provides useful insights into the mechanism and the treatment of the yips. Interdisciplinary studies that aim to elucidate the cause of the yips and develop effective intervention are necessary.

Paired Comparison of Technical Factors Influencing Javelin Aerodynamic Distance / 医用生物力学

Objective To determine the effects of javelin release parameters related to aerodynamics on aerodynamic distance and results in javelin throwing in actual competition environments. MethodsKinematic data from javelin throwing of 22 Chinese and American elite women javelin throwers were obtained using three-dimensional videographic method. The trial with the longest aerodynamic distance and the trial with the shortest aerodynamic distance for each thrower in the same competition were included in this study. Aerodynamics-related techinical parameters in long and short aerodynamic distance trials were compared. Results Compared with short aerodynamicdistance trials, the vacuum flight distances of long aerodynamic distance trials were significantly shorter, but the official distances were significantly longer. The release velocities of long aerodynamic distance trials were significantly lower, the attack angles and bending angles were significantly smaller. The horizontal direction angles at release of the long aerodynamic distance trials were more to the right side. The elevation angles and horizontal pointing angles during right/left foot landing in long aerodynamic distance trials were not significantly different from those in short aerodynamic distance trials. Conclusions Throwing javelin with submaximal effort beneficiates the control of aerodynamics-related release parameters and thus increased chances to obtain long aerodynamic distance and better result in women javelin throwing. Reducing attack angle and releasing javelin about 5°to the right will assist women javelin throwers to obtain longer aerodynamic distance.

Variations in shoulder loading due to differences in the site of stepping foot contact during baseball pitching - Comparison between flat ground and mound conditions - / 体力科学

This study examined variations in shoulder loading due to differences in the site of stepping foot contact during baseball pitching, while comparing flat ground and mound conditions. Measurement was performed, involving 10 right-handed pitchers who belonged to university baseball clubs, under original flat ground and mound conditions. Pitching movements were classified into 3 categories: [normal], [narrow], and [outside]. Through 3-dimensional motion analysis using a motion capture system, the following results were obtained: 1. The pitching velocity was significantly higher in the [normal] compared with [narrow] and [outside] conditions and under the mound compared with flat ground condition. 2. The peak torque of the shoulder internal rotation was markedly lower in the [narrow] compared with [normal] condition. There were no significant differences between the [normal] and [outside] conditions or between the flat ground and mound conditions. 3. The posterior, superior, and inferior shearing forces, as well as the proximal traction force, which influence the humeral head of the shoulder, were markedly greater in the [normal] compared with [narrow] and [outside] conditions. The anterior and posterior shearing forces and proximal traction force were significantly greater under the mound compared with flat ground conditions. Based on the results, the internal rotation torque of the shoulder, as well as the shearing and traction forces influencing the humeral head of the shoulder, may vary due to differences in the site of stepping foot contact during baseball pitching and between flat ground and mound conditions. The former may also be useful to prevent pitching-related shoulder injuries.

Partial Thickness Rotator Cuff Tears of the Shoulder Related to the Sports / 대한정형외과학회잡지

A painful shoulder is common among athletes, particularly those involved in overhead throwing. Professional and recreational athletes in throwing activities have an increased risk of partial thickness tears of the rotator cuff. The manuscript was to reviews the literature on the characteristics of injury, treatment strategies, and their results in throwing athletes.

Discrete motor skill acquisition: effect of number of visual demonstrations / Aquisição de habilidade motora discreta: efeito do número de demonstrações

ABSTRACT This experiment investigated the effect of number of visual demonstrations on the acquisition of discrete motor skill. Seventy-four college students of both sex participated in this study. The participants observed a visual model twice or ten times. In the acquisition phase, the participants were asked to throw a dart with postero-anterior movement into a circle target until reach a learning criterion. In transfer tests no difference between groups was found in the analysis of score. However, ten demonstrations were more effective than twice as regards performance of the correct pattern of movement and the number of subjects who reached the performance criterion. The results indicate a similar effect of the both number of demonstrations in the performance and dart throwing learning and both conditions influence subject's capacity to detect relevant information to perform the task.

RESUMO Este experimento investigou os efeitos do número de demonstrações na aquisição de uma habilidade motora discreta. Setenta e quatro universitários, de ambos os sexos, participaram desse estudo. Os participantes observaram um modelo duas ou dez vezes. Na fase de aquisição, os participantes foram requisitados a lançar um dardo por meio de um movimento antero-posterior em um alvo circular até atingir um desempenho critério. Não foram identificadas diferenças na aprendizagem entre os grupos na análise do escore. Contudo, dez demonstrações estimularam melhor do que duas demonstrações no que diz respeito ao desempenho do padrão correto e ao número de sujeitos que atingiram o desempenho critério. Os resultados indicam um efeito similar de ambos os números de demonstrações no desempenho e aprenizagem do arremesso de dardo de salão e que ambas as condições estimularam a capacidade dos aprendizes de detectarem informações relevantes para desempenhar a tarefa.

Feasibility of a New Desktop Motion Analysis System with a Video Game Console for Assessing Various Three-Dimensional Wrist Motions

BACKGROUND: The restriction of wrist motion results in limited hand function, and the evaluation of the range of wrist motion is related to the evaluation of wrist function. To analyze and compare the wrist motion during four selected tasks, we developed a new desktop motion analysis system using the motion controller for a home video game console. METHODS: Eighteen healthy, right-handed subjects performed 15 trials of selective tasks (dart throwing, hammering, circumduction, and winding thread on a reel) with both wrists. The signals of light-emitting diode markers attached to the hand and forearm were detected by the optic receptor in the motion controller. We compared the results between both wrists and between motions with similar motion paths. RESULTS: The parameters (range of motion, offset, coupling, and orientations of the oblique plane) for wrist motion were not significantly different between both wrists, except for radioulnar deviation for hammering and the orientation for thread winding. In each wrist, the ranges for hammering were larger than those for dart throwing. The offsets and the orientations of the oblique plane were not significantly different between circumduction and thread winding. CONCLUSIONS: The results for the parameters of dart throwing, hammering, and circumduction of our motion analysis system using the motion controller were considerably similar to those of the previous studies with three-dimensional reconstruction with computed tomography, electrogoniometer, and motion capture system. Therefore, our system may be a cost-effective and simple method for wrist motion analysis.

Effect of post-activation potentiation in Athletics: a systematic review / Efeito da potencialização pós-ativação no Atletismo: uma revisão sistemática

Abstract Post-activation potentiation is a physiological phenomenon reported to increase muscle performance during high-intensity exercise. To induce post-activation potentiation, maximal strength or power short-duration activities are performed minutes prior the main activity in an attempt to enhance performance. The aim of this study was to evaluate previous publications on the effects of post-activation potentiation on athletic performance. This systematic review used Scielo, Pubmed and SporDiscus database with the following search terms either alone or grouped together: post-activation potentiation, exercise, athletics, track and field, sprint, long jump, triple jump, high jump, shot put, javelin throw, hammer throw e discus throw. The review provided evidence that performing squat, jump and sprint exercises prior to the main activity elicited a state of potentiation that would improve sprint and throw performances and that preparatory activities that can cause post-activation potentiation should be used to improve athletic performance.

Resumo A potencialização pós-ativação é um fenômeno fisiológico capaz de aumentar o desempenho muscular durante exercícios de alta intensidade. Para induzir a potencialização pós-ativação, atividades de curta duração com força máxima ou potência muscular são realizadas minutos antes da atividade principal na tentativa de aumentar o desempenho. O objetivo deste estudo foi avaliar as publicações anteriores sobre os efeitos da potencialização pós-ativação sobre o desempenho no atletismo. Esta revisão sistemática utilizou os bancos de dados Scielo, Pubmed e SportDiscus com os seguintes termos de pesquisa juntos ou separados: post-activation potentiation, exercise, athletics, track and field, sprint, long jump, triple jump, high jump, shot put, javelin throw, hammer throw e discus throw. A revisão evidenciou que a realização de agachamentos, saltos e sprints, antes da atividade principal, desencadeia o estado de potencialização, que então aumenta o desempenho de sprints e lançamentos, e que atividades preparatórias que causam potencialização pós-ativação podem ser utilizadas para aumentar o desempenho no atletismo.

Risk factors survey and preventive measures analysis of grenade throwing fractures during the military training in recruits / 解放军医学杂志

Objective To analyze risk factors for grenade throwing fractures and put forward corresponding preventive measures for the fractures during the military training in recruits,so as to reduce the happen in the military training.Methods The research is case-control study.The trial group and the control group (39 patients each) were followed up and investigated.The investigation indicators included height,body mass index (BMI),whether drinking carbonated beverage frequently,literacy,osteoporosis,throwing training score,throwing posture,warm-up sufficiently,region,whether attend often physical exercise before recruitment,exercise strength,and weather factor.Results There were significant differences in the warm-up sufficiency,attending physical exercise before recruitment,exercise intensity,throwing posture,weather factor between trial group and the control group in recruits.The logistic regression analysis showed that the lack of physical exercise before recruitment,strong exercise intensity,nonstandard throwing posture were the risk factors in grenade throwing fractures in recruits.Conclusion Sufficient warm-up,avoiding exhausted exercise and assault exercise,strict training in accordance with the standard throwing posture,regular participation in physical exercise before recruitment and training in warm season are effective methods for preventing grenade throwing fractures in recruits.

Efecto agudo de Complex Training en press banca sobre la distancia del lanzamiento de la granada / Acute effect of a Complex Training over grenade throwing distance

Objetivo: determinar el efecto agudo de un Complex Training en press banca sobre el lanzamiento de la granada en pentatletas militares profesionales y aficionados. Métodos: diecinueve pentatletas militares divididos en dos grupos fueron parte del estudio. Las variables medidas fueron: distancia máxima del lanzamiento de la granada y potencias máximas en press banca. El protocolo consistió en: 4 series de 5 repeticiones al 30 por ciento de una repetición máxima, más 4 repeticiones al 60 por ciento de una repetición máxima, más 3 lanzamientos de granada con pausa de 15 segundos. Para el análisis estadístico se utilizó ANOVA de medias. Resultados: la distancia máxima del lanzamiento de la granada presentó un aumento significativo entre la Serie Control y las cuatro series experimentales para el Grupo Profesional (p= 0,0019, tamaño del efecto= 0,370) y un descenso significativo en el Grupo Aficionado (p= 0,0128, tamaño del efecto = 0,305); las potencias máximas en press banca no sufrieron modificaciones significativas en ambos grupo (Grupo Profesional p= 0,15, tamaño del efecto= 0,166; Grupo Aficionado p= 0,17, tamaño del efecto= 0,199). Conclusión: el efecto agudo positivo del Complex Training fue atribuido a la Potenciación Posactivación de la musculatura involucrada en el lanzamiento. El descenso significativo en el lanzamiento de la granada observado en el Grupo Aficionado fue atribuido a la imposibilidad de sintetizar ATP posesfuerzo, lo que indujo una fatiga muscular(AU)

Purpose: Determining the acute effect of a Complex Training in bench press over grenade throwing in professional and amateur military pentathletes. Methods: Nineteen military pentathletes divided into two groups were part of the study (Professional Group = 10 and Amateur Group = 9). Variables measured were: Distance maximum in grenade throwing and peak power in bench press. Complex Training protocol consisted of: 4 sets of 5 repetitions at 30 percent of one repetition maximum + 4 repetitions at 60 percent of one repetition maximum + 3 grenade throws with a 15-second rest. For the statistical analysis, repeated measures ANOVA was used, the effect size was estimated with Eta Partial Squared. Results: Distance maximum of grenade throwing showed a significant increase between the Control Set and the four experimental sets for the Professional Group (p = 0.0019, effect size = 0.370) and a significant decrease in the Amateur Group (p = 0.0128, effect size = 0.305); peak power in bench press did not suffer significant modifications in both groups (Professional Groupp = 0.15, effect size = 0.166; Amateur Group p = 0.17, effect size = 0.199). Conclusions: The results of the study showed a positive acute effect from Complex Training on the distance of grenade throwing only for professional military pentathletes, such effect was attributed to a Post-Activation Potentiation of the muscles involved in throwing. The significant decline in grenade throwing observed in the amateur military pentathletes was attributed to the impossibility of synthetizing ATP post-workout(AU)

A Case of Throwing Fracture of the Humerus in a Amateur Baseball Pitcher

Spiral fractures of the humerus that occur during throwing, such as in baseball, are not very common but have been well described in orthopedics and sports medicine. They are known to occur by sudden extreme muscular action while throwing balls. I report on a case of spiral fracture of the humerus shaft while pitching in a baseball game with a review of the literature.

Trial of a new lower limbs and trunk functional evaluation for pitcher -physical characteristic of the baseball player with throwing disorder- / 体力科学

Pitching motion is made up by three-dimensional whole body movement. Pelvic and trunk rotation movement is important for the prevention of throwing injuries. Throwing is not a simple rotation movement. Evaluation should reflect muscle strength, coordination, and pitching motion characteristics. We have devised throwing rotational assessment (TRA) similar to throwing as the new evaluation of total rotation angle required for throwing. The purpose of this study was to introduce the new method and to examine the characteristics of players with throwing disorders. The subjects were 76 high school baseball pitchers who participated in the medical check. Pain-induced tests were elbow hyperextension test and intra-articular shoulder impingement test. Pitchers who felt pain in either test were classified as disorder group. TRA evaluation was performed as follows. In the positions similar to the foot contact phase, rotation angles of the pelvis and trunk were measured. In the position similar to follow through phase, the distance between the middle finger and the second toe was measured. All tests were performed in the throwing and opposite direction. Twenty five pitchers were classified as disorder group. All TRA tests in healthy group were significantly higher in the throwing direction than in the opposite direction, but there was no significant difference in the disorder group. Disorder group had significantly lower average rotation angles of the pelvis and trunk in the throwing direction and rotation angle of trunk in the opposite direction than the healthy group. Restrictions on TRA reflecting the complex whole body rotation movement may be related to the throwing disorder. This evaluation is a simple method. It would be useful early detection of throwing disorder and systematic evaluation in medical check, as well as self-check in the sports field.

The prediction of pitching injuries of the shoulder and elbow by comparing the ROM between dominant and non-dominant side on neck/trunk rotations and hip internal rotation / 体力科学

The pitching motion requires neck, trunk and hip rotations. The purpose of this study was to investigate the relationship between pitching injuries and dominant versus non-dominant differences of the ranges of these motions. The subjects were 66 high school baseball pitchers who received medical checkup during baseball classes in Kyoto prefecture. During medical checkup, physical therapists measured the ranges of neck/trunk rotations, and internal rotation of the bilateral hips. Then orthopaedic doctors did special tests such as shoulder internal impingement test, subacromial impingement test, elbow valgus stress test and elbow hyper extension test. Fourteen pitchers (21.2%) who were positive in one or more special tests were judged to require second screening (injured group). In normal group, average neck/trunk rotations toward the non-dominant side were significantly wider than rotations toward the dominant side. Average hip internal rotation was significantly wider on the non-dominant side than on the dominant side. In injured group, a larger number of pitchers had wider neck and trunk rotation ranges toward the dominant side than toward the non-dominant side, and had wide hip internal rotation range on the dominant side compared to the non-dominant side. Comparing the ranges of the neck/trunk rotations and hip internal rotation between dominant and non-dominant sides might be useful for the prediction of pitching injuries of the shoulder and the elbow.

Efeitos do estabelecimento de metas para a aquisição de uma habilidade motora / Effects of goal setting for the acquisition of motor skills / Efectos de la fijación de metas para la adquisición de habilidades motoras

O presente estudo investigou os efeitos do estabelecimento de metas de curto e de longo prazo na aprendizagem do arremesso de dardo de salão. O experimento foi conduzido em três etapas: pré-teste (10 tentativas); aquisição (60 tentativas), com manipulação da temporalidade da meta; e pós-teste (10 tentativas). Os 33 universitários destros foram divididos em três grupos: meta específica de curto prazo (GEC), meta específica de longo prazo (GEL) e o não meta (GNM). Na análise da precisão e da consistência, a ANOVA two way identificou diferença entre pré-teste e pós-teste e entre os blocos da aquisição. Apesar de todos os grupos terem aprendido a tarefa, não houve diferença entre eles. Sugere-se a realização de novos estudos sobre o tema.

The present study investigated the effects of short and long-term goal setting in the learning of saloon dart throwing. The experiment was conducted in three stages: pretest (10 trials), acquisition (60 trials), with manipulation of the temporality of the goal, and post-test (10 trials). The 33 right-handed university students were divided into three groups: specific short-term goal (GEC), specific long-term goal (GEL) and no-goal (GNM). In the analysis of accuracy and consistency the two way ANOVA identified significant effect between pretest and post-test and between acquisition blocks as well. Although all the groups have learned the task, there was no difference between them. It is suggested further researches on the subject.

El presente estudio investigó los efectos de la meta a corto y largo plazo de puesta enel aprendizaje del salón de lanzar dardos. El experimento se llevó a cabo en tres etapas: pre-test (10 ensayos), la adquisición (60 ensayos), con la manipulación de la temporalidad de la meta, y después de la prueba (10 ensayos). Los 33 estudiantes universitarios de la mano derecha se dividieron en tres grupos: objetivo concreto a corto plazo (GEC), el objetivo específico a largo plazo (GEL) y no se meta (GNM). En el análisis de la exactitud y la consistencia de dos vías ANOVA identificó un efecto significativo entre la pre y post-test y entre bloques de adquisición así. A pesar de todos los grupos han aprendido la tarea, no hubo diferencias entre ellos.