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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Proposição de uma metodologia para coleta de dados da virada no nado crawl / Propose a procedure for swimming turns analysis

Silveira, Graziela Aveline 17 August 2007 (has links)
Made available in DSpace on 2016-12-06T17:07:14Z (GMT). No. of bitstreams: 1 Graziela Aveline Silveira.pdf: 1332545 bytes, checksum: 1fe1462c582ad215775d8d0f43aab4a7 (MD5) Previous issue date: 2007-08-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to propose, through biomechanical methods, a procedure for swimming turns analysis, regarding the distance of performance measurement and the number of executions. The study was characterized as descriptive. Data collection was carried out at the swimming pool of CEFID/UDESC and in Aquatic Biomechanics Research Laboratory. The sample was composed by 11 subjects of Limit Swimming Team, from Florianópolis, SC, all of them associated to the Aquatic Federation of Santa Catarina (FASC). Six video cameras (f = 30Hz) and an underwater force plate were used. Because of its thickness, the force plate was placed in a frame in order to simulate the real conditions of the swimming pool wall. Each swimmer performed 8 turns. Dynamic data were analyzed in SAD 32 System and kinematic data were analyzed through image edition software. Analyzed variables: normalized force peak (PMn), contact time (TC), impulse (Imp), total turn time in 10 meters (TV10m) and total turn time in 15 meters (TV15m). Descriptive statistics was used to present data and the relationship between the variables was verified through Spearman s test (p<0,05). In order to determine the number of executions, Mann-Whitney U test and Kruskal-Wallis test were used, and also values of accumulated average and accumulated coefficient of variation. The results showed that for athletes with the same characteristics of the analyzed swimmers, the turn performance should be measured in 10 meters, because when analyzing turn performance in 15 meters, 67% of total time corresponds to stroke time, while in the 10 meters analysis, stroke time represents 48% of total turn time. Besides, the relationship between the PMn, TC and Imp with turn performance is very similar when comparing TV10m and TV15m. On this way, considering turn performance in 10 meters, one could collect data with fewer cameras and still the evaluation would be focused on turn actions and not on the stroke phase. Regarding the number of executions, all of the tests comparing groups of executions showed no difference. Otherwise, the values of accumulated coefficient of variation graphically showed stabilization starting on the third execution. The values of accumulated average showed that increasing the number of executions, the turn performance decreases, which could be related to swimmer s fatigue. So, one suggest that for turn performance analysis, as a safety procedure, four executions should be performed (one more than results observed) in order to be able to ignore a non-valid one. / Este estudo teve como objetivo propor uma metodologia para realização de coletas de dados na virada no nado Crawl, através de métodos de medições biomecânicas levando em consideração a distância para analise da performance e o número de execuções. É caracterizado como um estudo descritivo. Os dados foram coletados nas dependências da piscina do CEFID/UDESC e tratados no Laboratório de Pesquisas em Biomecânica aquática da mesma instituição. Os sujeitos da pesquisa foram 11 nadadores da Equipe da Academia Limit, Florianópolis, SC, federados junto a Federação Aquática de Santa Catarina (FASC). Para coleta de dados foram utilizadas seis câmeras filmadoras (f=30Hz) e uma plataforma de força subaquática, acoplada a um suporte para fixação na parede da piscina e embutida em uma moldura com a finalidade de fornecer aos atletas a sensação de estarem tocando na parede da piscina. Cada nadador realizou 8 execuções. Os dados dinamométricos foram processados pelo sistema SAD 32 e os cinemático por softwares de edição de imagem. Variáveis analisadas: pico de força (PMn), tempo de contato (TC), impulso (Imp), tempo de virada em 10 metros (TV10M) e tempo de virada em 15 metros (TV15m). Foi utilizada estatística descritiva e para relacionar as variáveis foi utilizado o teste de Spearman (p<0,05). Para determinar o número de execuções foi utilizado o teste U de Mann-Whitney e Kruskal-Wallis, assim como valores de média acumulada e coeficiente de variação acumulado. Através dos resultados foi possível observar que para avaliar um grupo de atletas com características semelhantes as dos atletas deste estudo, a performance na virada deve ser verificada em 10 metros, pois quando analisada a performance em 15 metros, 67% do tempo total de virada corresponde ao nado, enquanto que ao se analisar a performance em 10 metros, o tempo de nado representa 48% do tempo total de virada. Considerando a performance em 10 metros facilita a coleta de dados, utilizando menor número de câmeras focando a análise na virada propriamente dita e não na fase de nado. Com relação ao número de execuções, todos os testes utilizados para comparar os grupos de execuções não mostraram diferenças. Entretanto, os valores de coeficiente acumulado apresentaram graficamente uma estabilização a partir da terceira repetição. Através dos valores de média acumulada foi observado que quando o número de execuções aumenta, a performance da virada diminui, o que poderia ser relacionado a fadiga do nadador. Portanto, sugere-se que a performance da virada, seja avaliada com quatro execuções (uma a mais que observada nos resultados), como forma de segurança para o pesquisador.
2

Efeitos de diferentes tamanhos de palmares nos indicadores tecnicos do nado crawl em esforços maximos de 50 e 100m / Effects of different hand paddles in technical parameters on front crawl swimming in 50 and 100m maximal efforts

Martinho, Ulisses Guimarães 02 December 2009 (has links)
Orientador: Orival Andries Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica / Made available in DSpace on 2018-08-13T08:42:29Z (GMT). No. of bitstreams: 1 Martinho_UlissesGuimaraes_M.pdf: 2656591 bytes, checksum: caad5fcd63eb52c9ffa6807b90c1d902 (MD5) Previous issue date: 2009 / Resumo: Os aspectos físicos e técnicos do treinamento são fatores determinantes para o desempenho, inclusive na natação (VERKHOSHANSKY, 2001). O palmar é um instrumento de treino utilizado para desenvolvimento da força especial no qual o nadador, ao utilizá-lo, mantém os padrões técnicos semelhantes ao nado sem o material. Além disso, o palmar promove aumento da força propulsiva e da potência (GOURGOULIS et al., 2006). Diferentes tamanhos e formatos desse material dificultam um melhor conhecimento sobre suas características. Com isso o presente estudo teve por objetivo verificar os efeitos de três tamanhos de palmar (PP, PM e PG), de mesmo formato, nos indicadores técnicos do nado Crawl. Oito nadadores homens expressivos em nível estadual realizaram, em quatro sessões de controle, esforços máximos nas distâncias de 50m e 100m com e sem o material. Foram avaliados velocidade média, freqüência e comprimento de braçadas. Foram realizados testes estatísticos de normalidade, variância e significância. Com o uso do palmar houve aumento da velocidade média e do comprimento de braçada, indicando possível melhora da eficiência propulsiva, especialmente em PM e PG. Por outro lado, a freqüência de braçada não sofreu alterações significantes, contrariando o que a literatura tem colocado. PM e PG parecem estabilizar a técnica de nado, exceto PP que apresentou características próximas ao nado sem o material, parecendo não ser indicado para o trabalho de força especial no nado Crawl. / Abstract: The technical and physical of training are determinative factors for performance, also in swimming (VERKHOSHANSKY, 2001). Paddles is an instrument of specific strength training that presents similar technical parameters to free swimming, beyond promoting increase of the propulsive force of power (GOURGOULIS et al., 2006). Different sizes and formats of this material make it difficult the knowledge of its characteristics. The present study had for objective to verify the effect of three sizes of paddles (PP, PM and PG), of same format, in technical parameters in front Crawl swimming. Eight swimming competitive men in state level had carried through, in four sessions of tests, maximum efforts in distances of 50m and 100m with and without paddles. Average speed, pull frequency and pull length had been evaluated. Statistical tests of normality, variance and significance had been carried through. The use of paddles increases the average speed and the pull length, indicating possible improvement of the propulsive efficiency, especially with PM and PG. On the other hand, the pull frequency did not suffer significant alterations, opposing what literature has placed. PM and PG seems to stabilize the technique of swimming, but not PP, with presented next characteristics of swimming without paddles, seeming to be not indicated for specific strength training in front Crawl swimming. / Mestrado / Ciencia do Desporto / Mestre em Educação Física
3

Étude expérimentale et numérique, en écoulement instationnaire, du trajet des bras en crawl à différentes allures de nage / Experimental and numerical study in unsteady flow of the arm stroke in the front crawl at different paces of swimming

Samson, Mathias 17 June 2016 (has links)
Le crawl est actuellement la nage utilisée lors des épreuves de nage libre durant les compétitions de natation aux différentes allures de nage (sprint, demi-fond et fond). Les bras sont les segments corporels qui participent le plus à la propulsion. Les accélérations de ces segments, dans le milieu fluide au repos, génèrent un écoulement complexe qui est à l'origine des forces hydrodynamiques propulsives. L'analyse de cet écoulement est nécessaire pour en comprendre les principaux mécanismes. Dans ce cadre, des « paramètres cinématiques d'écoulement » (vitesse, accélération et orientation de la main, angles d'attaque et de sweepback) ont été définis afin d'analyser et comparer les différentes organisations gestuelles des nageurs et de leurs effets sur la propulsion. Deux des principaux axes d'investigation étaient de vérifier si ces paramètres variaient en fonction de l'allure, et aussi de déterminer quels paramètres cinématiques étaient les plus prépondérants dans la génération des mécanismes propulsifs. Pour cela, un système opto-électronique d'analyse cinématique, a permis de mesurer ces paramètres sur 17 nageurs experts. Par ailleurs, l'écoulement généré par le trajet des bras aux différentes allures a été simulé par résolution numérique instationnaire des équations de Navier-Stokes. Enfin, des mesures expérimentales d'effort ont été faites en nage attachée afin de connaître les forces propulsives.Il apparaît que l'augmentation de l'allure de nage peut davantage s'expliquer par la diminution des durées des phases non propulsives (entrée et allongement) plutôt que par l'augmentation des forces durant les phases les plus propulsives (balayages interne et externe). / Front crawl is a swimming stroke used at swimming competitions at freestyle different paces (sprint, middle distance and long distance). Propulsion in this stroke is achieved primarily by the forearm and hand. Accelerations of these segments, in a fluid at rest, generate complex flow that causes propulsive hydrodynamic forces. Analysis of this flow is necessary to understand the main mechanisms of propulsion. In this context, the "kinematic flow parameters" (velocity, acceleration and orientation of the hand, angles of attack and sweepback) have been defined to analyze and compare the different arm motions and their effects on propulsion. Two of the main axes of this investigation were to determine whether these parameters vary depending on the pace, and also to determine what kinematic parameters were most prominent in the generation of propulsive mechanisms. To this end, an optoelectronic system of motion capture was used to measure these parameters on 17 expert swimmers in free swimming. Furthermore, the flow generated by the experimentally acquired arm trajectory, at different swimming paces, was simulated by an unsteady numerical solution of the Navier-Stokes equations. Finally, tethered swimming experiments were carried out to measure the propulsive forces.The increase in forward velocity by increasing swimming pace can be explained by lower durations of non propulsive phases (entry and stretch) rather than by the generation of higher forces during the most propulsive phases (insweep and upsweep).

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