Caracterização cinesiológicado choku­tsuki executado comimpacto e sua comparação coma execução semimpacto

espanolObjetivo: Este trabajo pretende caracterizar la cinematica y electromiografia de un punetazo basico de karate (choku­ zuki) realizado con impacto sobre un objetivo (makiwara) por karatekas experimentados, y compararlo con la ejecucion sin impacto real (control). Esta caracterizacion permite al entrenador (sensei) conocer como influye el entrenamiento en la ejecucion del punetazo en cada una de estas circunstancias, y a partir de esa informacion es posible definir estrategias de entrenamiento adaptadas a sus objetivos. Metodo: En una muestra de diez karatekas de la seleccion portuguesa se recogieron datos cinematicos y electromiograficos durante la ejecucion del choku­zuki, con impacto y sin impacto, en relacion a los segmentos del brazo y del antebrazo. Resultados: Se verifico que la actividad cinematica y neuromuscular en la realizacion del choku­zuki sucede en un intervalo de tiempo inferior a 300 ms. La actividad muscular y segmentaria estudiada muestra una tendencia de activacion secuencial, en un sentido proximo-distal, teniendo la musculatura implicada del brazo mayor intensidad de activacion que los musculos del antebrazo. Los movimientos de flexion del brazo realizados en la articulacion del hombro y de extension del antebrazo realizados en la articulacion del codo son efectuados con gran amplitud. La pronacion del antebrazo en la articulacion del codo no es completa y tiende a ser el movimiento segmentario que inicia la ejecucion del choku­zuki. Conclusion: Las ejecuciones del choku­zuki con y sin impacto son cinesiologicamente diferente. Esta diferencia realza la importancia que los entrenadores deberian dar a la ensenanza de la ejecucion y al entrenamiento del punetazo con impacto efectivo en el objetivo. portuguesAim: This work aims to characterize the kinematics and electromyography of a basic karate punch (choku-zuki) made with an impact on a target (makiwara) by experienced karateka, and compares it with the execution without real impact on the target (control). This characterization allows to the coach (sensei) to know how training influences the performance of the punch in each one of these circumstances, and from that information it is possible to define strategies of training that considers adapted to its goals. Method: In a sample of ten male karateka of the Portuguese Karate Team the kinematic and electromyographic data of the arm and forearm segments were collected during the execution of choku-zuki, with impact and no impact. Results: It was found that the kinematics and neuromuscular activity in the performance of choku-zuki happens in a time interval less than 300ms. The studied muscles activity and segments of the upper limb shows a trend of activation sequence with a proximal to distal direction, with the intervening segment arm muscles having a greater intensity of activation that the muscles involved in the forearm segment. The arm flexion at the shoulder joint and the forearm extension at the elbow joint are done with greater amplitude, and the forearm pronation is not complete at the time of impact. The forearm pronation at the elbow joint is not complete and tends to be the first segmental movement in the choku-zuki execution. Objectivos: Este trabalho tem como objetivo efetuar a caracterizacao cinematica e electromiografica de um soco basico de karate (choku­zuki) realizado com impacto num alvo (makiwara) por karatecas experientes, e comparar com a execucao sem impacto efetivo no alvo (com controlo). Esta caracterizacao permite ao treinador (sensei) saber como o treino influencia a realizacao do soco em cada uma destas vertentes, e a partir dessa informacao definir estrategias de treino que considere adequadas aos seus objetivos. Metodo: Numa amostra de dez karatecas masculinos da selecao Portuguesa foram recolhidos dados cinematicos e electromiograficos durante a execucao do choku­zuki, com impacto e sem impacto, relativamente aos segmentos braco e antebraco. Resultados: Verificou-se que a actividade cinematica e neuromuscular na realizacao do choku­zuki acontece num intervalo de tempo inferior a 300 ms. A actividade muscular e segmentar estudada mostra uma tendencia de activacao sequencial com um sentido proximo-distal, com a musculatura interveniente no segmento braco a ter maior intensidade de ativacao que os musculos intervenientes no segmento antebraco. Os movimentos de flexao do braco realizados na articulacao do ombro e de extensao do antebraco realizado na articulacao do cotovelo sao efetuados com grande amplitude. Ja a pronacao do antebraco realizada na articulacao do cotovelo nao e completa e e tendencialmente o movimento segmentar que inicia a execucao do choku­zuki. Conclusao: Comparativamente a execucao do choku­zuki com impacto e sem impacto e cinesiologicamente diferente. Esta diferenca realca a importância que os treinadores deverao dar ao ensino da execucao e treino do soco com impacto efetivo no alvo EnglishAim: This work aims to characterize the kinematics and electromyography of a basic karate punch (choku-zuki) made with an impact on a target (makiwara) by experienced karateka, and compares it with the execution without real impact on the target (control). This characterization allows to the coach (sensei) to know how training influences the performance of the punch in each one of these circumstances, and from that information it is possible to define strategies of training that considers adapted to its goals. Method: In a sample of ten male karateka of the Portuguese Karate Team the kinematic and electromyographic data of the arm and forearm segments were collected during the execution of choku-zuki, with impact and no impact. Results: It was found that the kinematics and neuromuscular activity in the performance of choku-zuki happens in a time interval less than 300ms. The studied muscles activity and segments of the upper limb shows a trend of activation sequence with a proximal to distal direction, with the intervening segment arm muscles having a greater intensity of activation that the muscles involved in the forearm segment. The arm flexion at the shoulder joint and the forearm extension at the elbow joint are done with greater amplitude, and the forearm pronation is not complete at the time of impact. The forearm pronation at the elbow joint is not complete and tends to be the first segmental movement in the choku-zuki execution. Conclusion: The executions of choku-zuki with impact and no impact are kinesiologically different. This difference highlights the importance that coaches should provide to teach and training the punch execution with an effective impact on the target.