ABSTRACT
Judo techniques use the assumption of maximum efficiency with minimum energy expenditure, which means to try to use the strength of the opponent against himself, causing an imbalance that, associated with a technique, helps execute a throw. This study is aimed to evaluate the mechanical efficiency of the seoi nage technique applied to judokas (uke) of different heights in relation to the thrower (tori). The knee and trunk angular variation of tori was compared with the total throw time, the time to perform each phase of the technique, and the behavior and vertical variation of the trajectory of tori's center of mass (ΔCM). Ten throws using the seoi nage technique on three uke of shorter, equivalent, and taller statures compared to tori were cinematically analyzed. The images were recorded at 180 Hz using the Peak Motus System. The data was analyzed by descriptive statistics, ANOVA, and Tukey's post-hoc (p < 0.05). The tori's mechanical efficiency was greater when throwing a uke of a stature taller or of his same height, while the total throw time was shorter for a taller uke. The ΔCM of the tori was greater to throw a uke of a shorter stature. The conclusion is that the seoi nage technique is most effective when applied against opponents of heights equal to or taller than the tori.
As técnicas do judô usam o pressuposto da máxima eficiência com o mínimo dispêndio de energia, ou seja, buscam usar a força do oponente contra ele mesmo, causando um desequilíbrio que, associado a uma técnica de arremesso, facilita a aplicação da mesma. Este estudo objetivou avaliar a eficiência mecânica da técnica seoi nage aplicada em oponentes (uke) de diferentes estaturas em relação ao executante (tori). Foram comparados a variação angular do joelho e do tronco do tori, o tempo total de projeção, o tempo de cada fase de aplicação da técnica e o comportamento e a variação vertical da trajetória do centro de massa (∆CM) do tori. Foi realizada a análise cinemática de 10 projeções da técnica seoi nage com uke de estaturas menor, equivalente e maior que a do tori. As imagens foram adquiridas a 180 Hz, utilizando-se o Sistema Peak Motus. Para o tratamento dos dados, utilizaram-se estatística descritiva e ANOVA com post-hoc de Tukey (p < 0,05). Houve maior eficiência mecânica do tori ao projetar o uke de estatura maior e equivalente a sua; o tempo total de projeção foi menor para o uke mais alto; o ∆CM do tori foi maior para projetar uke de menor estatura. Conclui-se que a técnica seoi nage é mais eficiente quando aplicada contra oponentes com estaturas equivalentes ou maiores que a do tori.
ABSTRACT
Este estudo objetivou avaliar a eficiência mecânica do harai goshi aplicado em judocas de diferentes estaturas. Comparou-se: a variação angular de joelho, quadril e tronco do tori; o tempo para realizar cada fase da técnica; o deslocamento da trajetória vertical do centro de massa (ΔCM) do tori. Analisou-se cinemáticamente 10 aplicações do harai goshi pelo tori de estatura intermediária contra três uke (um de estatura menor, um equivalente e um maior a dele). Realizou-se aquisições de imagens a 180 Hz, utilizando-se o Sistema Peak Motus. Os dados foram analisados por meio da estatística descritiva, ANOVA e pos-hoc de Tukey (p ≤ 0,05). No deslocamento angular, houve maior eficiência do tori ao projetar o uke de maior estatura. O tempo para projetar uke mais alto foi menor. O ΔCM apresentou o mesmo padrão de projeção. Conclui-se que a técnica harai goshi é mais eficiente quando aplicada contra oponentes de estaturas equivalentes ou maiores.
This study aimed to evaluate the mechanics efficiency of harai goshi applied in judocas of different heights. It was compared: the tori angular variation of knee, hip and trunk; the time to perform each technique phase; the displacement of the vertical trajectory of tori center of mass (ΔCM). Were analyzed 10 harai goshi kinematic throws, the tori with an intermediate height against three uke with lower, equivalent and higher height of him. The images were recorded at 180 Hz, using the Peak Motus System. The data were analyzed by means of descriptive statistics, ANOVA and pos-hoc of Tukey (p≤ 0,05). In the angular displacement, uke of higher stature had greater efficiency of tori when projecting. The time to project uke higher was lower. The ΔCM showed the same standard behaves. We conclude that the harai goshi technique is more efficient when applied against equivalent or higher opponents.
Subject(s)
Humans , Body Height , Martial ArtsABSTRACT
The obiective of this study was to describe the behavior of kinematics variables during children's gait with and without knapsack. The sample was canstituted af four female and two male school children aged between eight and nine. Two cameras with frequency af 60 Hz were used for data callection and Peak Motus system was used in data analysis. No differences in the spatial and temporal variableswere observed when subjects walked with and withaut backpack. These values were in accordance with the literature. Significant differences in velocity, cadence, trunk inclination and hip angle were found between gait with and without backpack. The behavior of hip angle was in accordance with the literature, hawever with greater values in gait using knapsack. This can be consequence of a compensatory posture af the trunk. Otherwise, the pelvis and knee angles did not present significant difference between gait with and without backpack