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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.
31

Análise da força de mordida, atividade eletromiográfica e espessura dos músculos masseter e temporal em nadadores de elite - modalidade Crawl / Analysis of bite force, electromiographic activity and thickness of masseter and temporal muscles in elite swimmers - crawl modality

Evandro Marianetti Fioco 12 December 2017 (has links)
O esporte aquático em todas as modalidades requer combinação de força e eficiência, pois a água tem densidade maior que o ar, e o nadador de elite que tem jornada aquática intensa com movimentos repetitivos na locomoção e respiração pode apresentar modificação de função e forma das estruturas que compõem o organismo humano. Esta pesquisa avaliou a força de mordida molar máxima, atividade eletromiográfica, eficiência mastigatória e espessura dos músculos masseter e temporal de nadadores de elite que utilizaram variações de métodos respiratórios do nado crawl para o lado direito e esquerdo, e comparou os resultados com indivíduos sedentários. Participaram 18 indivíduos na faixa etária entre 15 e 25 anos que foram distribuídos em três grupos: sedentários/controles (GC; idade média: 15,00 ± 0,98 anos; n=6); atletas que realizaram respiração para o lado esquerdo no nado crawl (GE; idade média 17,00 ± 2,44 anos; n=6) e atletas que realizaram respiração para o lado direito no nado crawl (GD; idade média 21,00 ± 2,44 anos; n=6). O dinamômetro digital Kratos foi utilizado para determinar a força de mordida molar máxima. O eletromiógrafo MyoSystem BR1 foi utilizado para avaliar a atividade eletromiográfica em repouso mandibular, lateralidade direita, lateralidade esquerda, protrusão, apertamento dental em contração voluntária máxima, mastigação habitual e não habitual (eficiência mastigatória). Foi utilizado o ultrassom Sono Site Titan para mensurar a espessura muscular em repouso e apertamento dental em contração voluntária máxima. Os dados obtidos foram tabulados e submetidos à análise estatística (SPSS 21.0, ANOVA; p ≤ 0,05). GE e GD demonstraram menor atividade eletromiográfica nas condições posturais da mandíbula quando comparados a GC. Foi observado correto padrão funcional nos movimentos mandibulares nas diferentes avaliações clínicas, com diferença significante na lateralidade direita para o músculo temporal esquerdo (p=0,04). GD e GE apresentaram maior eficiência mastigatória em relação ao GC, com diferença significante para o músculo temporal esquerdo na mastigação com uva passa (p=0,004). Não ocorreram diferenças significantes nas médias da espessura muscular e força de mordida molar entre os nadadores de elite e indivíduos sedentários. Estes resultados sugerem que nadadores de elite que utilizaram o nado crawl com métodos respiratórios variados apresentaram alterações funcionais nos músculos masseter e temporal. / All modalities of water sports require a combination of strength and efficiency, as the water has a higher density than air, and the elites swimmer has an intense aquatic journey with repetitive movements in the locomotion and breathing may present a modification of the function and shape of the body structures. This study evaluated the molar bite force, electromyographic activity, masticatory efficiency and thickness of the masseter and temporal muscle of elites swimmers used changes in respiratory methods both in right and left for crawl modality and compared the results with sedentary individuals. 18 individuals, aged between 15 and 25 years, were divided into three groups: sedentary/control (average ± SD 15.00 ± 0.98 years, n = 6; CG), athletes underwent respiration to the left side in the crawl swim (average ± SD 17.00 ± 2.44 years, n = 6; LG) and athletes who underwent respiration to the right side in the crawl swim (average ± SD 21.00 ± 2.44 years, n = 6, RG). The Kratos digital dynamometer was used to determine the molar bite force. The MyoSystem BR1 electromyograph was used to evaluate the electromyographic activity at mandibular rest, right laterality, left laterality, protrusion, maximum voluntary contraction, habitual and non-habitual mastication (masticatory efficiency). Sono Site Titan ultrasound was used to measure muscle thickness at rest and dental tightening at maximum voluntary contraction. The data were tabulated and submitted to statistical analysis (SPSS 21.0, ANOVA; P ≤ 0.05). LG and RG demonstrated lower electromyographic activity in postural conditions of the mandible when compared to CG. The correct mandibular neuroanatomic movement was observed in almost all muscles, with a significant difference in right laterality for the left temporal muscle (P=0.04). RG and LG presented greater masticatory efficiency in relation to the CG, with a significant difference for the left temporal muscle in chewing with raisins (P=0.004). There were no significant differences in the average muscle thickness and molar bite force between elite swimmers and sedentary individuals. These results suggest that elites swimmers perform crawl swimming with varied respiratory methods had functional alterations in the masseter and temporal muscles.
32

Feedback Após Boas e Más Tentativas de Prática na Aprendizagem do Nado Crawl / Feedback After Good Trials and Bad Trials of Practice in the Learning of Crawl Swimming Style.

Katzer, Juliana Izabel 26 March 2010 (has links)
Made available in DSpace on 2014-08-20T13:49:15Z (GMT). No. of bitstreams: 1 Juliana Izabel Katzer.pdf: 566998 bytes, checksum: 614a796bd05e530eed06282bbf0c345d (MD5) Previous issue date: 2010-03-26 / The learning of motor skills is a complex process. Depending on the task, obtaining a high level of skill can take years of practice. Several factors may influence the acquisition of skills in the motor learning environment as a distribution, quantity and variety of practical experiences, mental practice, demonstration and a major factor, the feedback. This study aims at verifying the motor learning of the beginning crawl swimming style, using feedback after good trials and bad trials. The present study evaluated 48 adult students with a mean age of 25.11±5.345 years, the Associação Desportiva da Universidade Federal de Santa Maria- RS. In order to check the motor learning the front crawl test was used Motor Performance of the Crawl wimming Style Test (Corazza et al., 2006) for the pre and post tests. Students were divided into two groups with 24 subjects each: group 1 (G1) received feedback after good trials to group 2 (G2) received feedback after bad trials at practice. The post test was carried out after 10 lessons in order to assess the learning of crawl swimming style. The findings of the pretest for to G1 was 3.46±3.55 points and for the G2 was 3.46 ± 3.14 points. And the results on the posttest was for the G1 26.29±2.33 for G2 and 23.85±5.47 points. There was found a significant difference for both groups (p<0.001). This shows that both groups learned after the 10 lessons, however, confirming the study purpose, the G1 obtained better results when compared to G2 p<0.001. From the results it was observed that the group that received feedback after good trials had a superior performance in crawl swimming style compared to the group that received feedback after bad trials at practice. This may be because of the feedback provided after good trials and it might motivate students to continue practicing, it is much easier for the beginner in motor skill to maintain the pattern of movement for the next trial. / A aprendizagem de habilidades motoras é um processo complexo. Dependendo da tarefa, obter um alto nível de habilidade pode tomar anos de prática. Vários fatores podem influenciar na aquisição de habilidades no ambiente da aprendizagem motora como, sendo um dos principais fatores, o feedback. Este estudo teve como objetivo verificar a aprendizagem motora de iniciantes do nado crawl, utilizando feedback após boas e más tentativas. Fizeram parte desse estudo 48 adultos universitários com média de idade de 25,11±5,345 anos, da Escola de Natação da Associação Desportiva da Universidade Federal de Santa Maria - RS. Para verificar a aprendizagem motora do nado crawl foi utilizado o Teste do Desempenho Motor do Nado Crawl de Corazza et al. (2006) para o pré e pós-testes. Os alunos foram divididos em dois grupos com 24 sujeitos cada: o grupo 1 (G1) que recebeu feedback após boas tentativas de prática e o grupo 2 (G2) que recebeu feedback após más tentativas de prática. Após 10 aulas de natação através da prática parcial progressiva, foi realizado o pós-teste para verificar a aprendizagem do nado crawl.Os resultados encontrados no pré-teste para o G1 de 3,46±3,55 pontos e para o G2 de 3,46±3,14 pontos. Já os resultados no pós teste para o G1 26,29±2,33 e para o G2 23,85±5,47 pontos. Foi encontrada uma diferença significante para ambos os grupos (p<0,001), o que mostra que ambos os grupos aprenderam após as 10 aulas, no entanto, confirmando hipótese do estudo, o G1 obteve resultados superiores quando comparado ao G2 (p<0,001). A partir dos resultados encontrados observouse que o grupo que recebeu feedback após boas tentativas teve um desempenho superior no nado crawl quando comparado ao grupo que recebeu feedback após más tentativas de prática. Esse fato pode ter ocorrido porque o feedback após boas tentativas além de motivar o aluno a continuar praticando, é muito mais fácil para o aluno iniciante numa habilidade motora manter o padrão do movimento para a próxima tentativa.
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Variabilité de la technique de nage : adaptabilité aux contraintes et performances en natation / Variability of swimming technique : adaptability to constraints and swimming performance / Variabilidad de la técnica de nado : adaptabilidad a las restricciones y al rendimiento en natación

Simbaña Escobar, David Napoleon 19 February 2018 (has links)
En compétition comme à l’entrainement, le comportement des nageurs émerge de l’interaction entre les ressources des nageurs et les contraintes éprouvées (organismique, environnementale et de tâche). L’objectif de ce travail est d’analyser la variabilité intra et inter-individuelle des aspects cinématiques du mouvement des nageurs en compétition et à l’entrainement. Nos résultats montrent l’existence d’une stabilité inter-longueur et une variabilité fonctionnelle intra-longueur dépendantes de la distance de l’épreuve, du genre et des différentes parties de la course en compétition. Les profils de gestion de course singuliers dépendent probablement des ressources mobilisables émotionnelles, cognitives, métaboliques et techniques. Les adaptations du nageur au cours d’un test maximal (9 X 25m) sans fatigue avec incrémentation aléatoire de la fréquence de nage a révélé la difficulté des nageurs à respecter des fréquences imposées situées au-delà de leurs fréquences préférentielles, et ce, surtout chez les nageuses. Pour les nageurs masculins, les fréquences éloignées des fréquences préférentielles ont induit une désorganisation motrice caractérisée par une augmentation des accélérations latérales et verticales. Ce travail propose des nouvelles pistes d’entraînement comme le travail individuel des stratégies de course inter et intra longueurs, et l’intérêt d’élargir la gamme de fréquences sollicitées afin d’acquérir une technique stable et économe, mais variable et adaptable en même temps. Cette variabilité faciliterait la mobilisation de leurs ressources pour développer une capacité et une flexibilité adaptatives permettant de surmonter les contraintes éprouvées. / In swimming competition just like in training, swimmers’ behaviours emerge from the interaction of constraints (organismic, environmental, and task). The aim of this work is to analyse the intra and inter-individual variability of the cinematic aspects of the movement of swimmers during competition and training. Our results have shown there is inter-lap stability and intra-lap functional variability in competition which depends on the distance of the race, the gender and the lap. Singular pacing profiles was discovered suggesting swimmers manage their speed differently depending on the available resources to deal with the race constraints. The swimmers’ adaptations at training during a protocol of 9 X 25m whilst increasing the stroke rate and the swimmers’ ability to respect an imposed frequency range was assessed, as well as the stroke rate amplitude range from the preferential and maximal stroke rate. Upon completion of the trials, the impact of stroke rate amplitude ranges on motor adaptability (coordination, efficiency) was evaluated. The difficult for all swimmers when performing above their preferential stroke rate, particularly for female athletes has been found and male swimmers exhibited disruption in forearm acceleration beyond their preferential stroke rate. This work proposes news paths for swimming training: working race strategies and training beyond the preferential stroke rate can allows swimmers to have a stable technique with a certain variability. This variability would give to swimmers the ability and flexibility to adapt and cope with constraints using their individual resources. / Durante la competencia o al entrenamiento, el comportamiento del nadador aparece de la interacción entre los recursos de él y sus restricciones encontradas (organísmicas, ambientales, y de acción). El objetivo de este trabajo es de analizar la variabilidad individual del aspecto cinemático del movimiento de nadadores en competencia y al entrenamiento. Nos resultados muestran la existencia de una estabilidad entre los largos y una variabilidad funcional al interior de cada largo, la cual depende de la distancia, el tipo de prueba, el género y de las diferentes partes de la carrera en situación de competencia. Los modelos singulares de la gestión de la carrera dependen probablemente de los recursos utilizados emocionales, cognitivos, metabólicos y técnicos. Las adaptaciones durante un test de sprint sin fatiga (9 X 25m) con una incrementación aleatoria de la frecuencia de nado han mostrado la dificultad de los nadadores a guardar la frecuencia pedida cuando es superior a la frecuencia preferencial (FRP), sobre todo en las nadadoras. Las frecuencias alejadas de la FRP inducen una desorganización motriz aumentación de aceleraciones laterales y verticales en los nadadores masculinos. Este trabajo propone nuevas pistas para el entrenamiento como el trabajo individual de las estrategias de carrera entre y al interior de cada largo, o el interés de aumentar el rango de frecuencias solicitado con el objetivo de adquirir una técnica estable y económica, así como variable y adaptable. Esta variabilidad facilitaría a los nadadores la movilización de sus recursos para desarrollar une capacidad a ser flexible y adaptativo, lo que podría permitir de superar las adversidades encontradas.
34

FUKTSKADOR I UTELUFTSVENTILERAD KRYPGRUND : Med avseende på klimatförändringar och installation av golvvärme

Louise, Breman, Andreas, Svensson January 2016 (has links)
Syfte: Idag riskerar cirka 300 000 hushåll med uteluftsventilerad krypgrund att bli angripna av fukt- och mögelskador. Klimatet i en uteluftsventilerad krypgrund påverkas i stor grad av temperaturen och den relativa luftfuktigheten. Det råder inga tvivel om att klimatet står inför förändringar, vilket innebär en höjd temperatur och en förändring av den relativa luftfuktigheten. Detta gör att den uteluftsventilerade krypgrunden inte har möjlighet att torka ut under vissa perioder på året och utsätts då för en förhöjd risk av fuktskador. Parallellt med klimatförändringen moderniseras även uppvärmningssystemen i småhusen, vilket ändrar förutsättningar för krypgrunderna. Målet med arbetet är att undersöka om klimatförändringarna och installation av golvvärme i träbjälklaget har bidragit till fuktskador i uteluftsventilerade krypgrunder och ge underlag till effektivare åtgärder av fuktskador. Metod: För att utreda om klimatförändringarna är ett problem för de uteluftsventilerade krypgrunderna har dokumentanalyser genomförts vilka sedan följdes av beräkningar av krypgrundens relativa luftfuktighet. På samma sätt gavs svar på om golvvärmen är en bidragande faktor till fuktskadorna. Båda frågeställningarna styrktes även av kvalitativa intervjuer med sakkunniga personer. Hur fuktskadorna effektivare kunde åtgärdas togs främst fram genom kvalitativa intervjuer men styrktes av dokumentanalyser. Resultat: Studien visar att klimatförändringarna kommer att påverka uteluftsventilerade krypgrunder i positiv bemärkelse då studien endast tog hänsyn till temperaturhöjningen. Installation av golvvärme har även visats vara positivt mot fuktskador i en uteluftsventilerad krypgrund om isolering i bjälklaget saknas eller är bristfällig. Branschen ser ingen vinst i att effektivisera åtgärdsmetoderna då dessa redan är välprövade och väl fungerande. Konsekvenser: Ett varmare klimat ger bättre förutsättningar för en uteluftsventilerad krypgrund. Medvetenheten om hur klimatförändringarna påverkar krypgrunderna ger byggbranschen ett försprång att förbereda sig inför kommande förändringar. Kunskapen om att golvvärme kan ge positiva effekter mot fuktskador i uteluftsventilerade krypgrunder ger nya förutsättningar för renoveringar och åtgärder mot fuktskador, dock måste energiförlusterna tas i hänsyn i dessa fall. Branschen ser ingen vinst i att effektivisera åtgärdsmetoderna, vilket gör att det inte finns någon anledning att gå djupare in i detta. Begränsningar: Arbetet behandlar endast uteluftsventilerade krypgrunder med träbjälklag som ligger inom Sveriges gränser. Denna studie är därför inte applicerbar på andra konstruktioner eller utanför Sveriges gränser. Endast klimatförändringarna det senaste seklet och fram till 2100 tas hänsyn till i rapporten. Studien tar heller inte hänsyn till fukttillskott från mark och dagvatten, likaså görs inga beräkningar på ventilation. / Purpose: Today are about 300 000 buildings with outdoor ventilated crawl space at risk to be contaminated by moisture and mold damage. An outdoor ventilated crawl space’s climate is greatly affected by the temperature and the relative humidity. There is no doubt that the climate is facing changes, which means an increased temperature and a change in the relative humidity. This prevents the outdoor ventilated crawl space from drying out during certain periods of the year and is then exposed to a heightened risk of moisture damage. Parallel to the climate change the heating systems are being modernized in houses, which changes the conditions for the crawl spaces. The objective of this essay is to do a research if climate change and the installation of underfloor heating in the greater part of the joist area has given rise to moisture damage in outdoor ventilated crawl spaces and provide good basis for more effective measures to moisture damage. Method: To investigate whether the climate change is a problem for outdoor ventilated crawl spaces have document analyzes been conducted, which was followed by calculations of the crawl spaces’ relative humidity. Calculations have been made to find out if the underfloor heating is a contributing problem to moisture damage. Both issues are also corroborated by interviews with qualified people. How the moisture damage more effective could be fixed was answered primarily through qualitative interviews, but corroborated by document analysis. Findings: The study shows that climate change will affect outdoor ventilated crawl spaces in a positive sense, only account to the temperature rise. Installing underfloor heating has also been shown to be positive against moisture damage in outdoor ventilated crawl spaces if insulation in the soffit is missing or deficient. The industry sees no gain in efficiency action methods as these are already proven and well- functioning. Implications: A warmer climate provides better conditions for outdoor ventilated crawl space. Being aware of the changes associated with climate change, and its effects on buildings give the construction industry a head start to prepare for future changes. Knowledge that underfloor heating can provide positive effects against moisture damage in crawl spaces creates new opportunities for renovations and actions against dampness but the energy losses in this case must be considered. Since the industry does not see profit in streamlining action methods is no need to go deeper into this. Limitations: The report deals only outdoor ventilated crawl spaces with wooden soffit that is located within the Swedish borders. This study is therefore not applicable to other constructions or other countries. Only climate change in the last century and up until 2100 are taken into account in the report. Further on the study does not take the excess moisture from the soil or the storm water into account; likewise there are no calculations for the ventilation.
35

Modelos mecânicos e fisiológicos do exercício nos domínios pesado e severo: comparação da potência e da resposta lactacidêmica nas condições de nado atado e desimpedido e da cinética do VO2 durante o crawl desimpedido

Pessôa Filho, Dalton Müller [UNESP] 13 April 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-04-13Bitstream added on 2014-06-13T19:00:57Z : No. of bitstreams: 1 pessoafilho_dm_dr_rcla.pdf: 1143306 bytes, checksum: b016fc73fb992fb299381a40997bc60e (MD5) / Não se tem observado a preocupação com a descrição dos domínios de intensidade na natação e poucas tentativas foram realizadas para ajustar o modelo de P-tLim às condições desta modalidade de exercício. Este estudo pretendeu ajustar o modelo P-tLim à natação com o recurso do controle de cargas possibilitado pelo nado em condição atada. Assim como, seu significado fisiológico para a descrição dos domínios pesado/severo obtido pelas relações a serem estabelecidas com a velocidade crítica (VC - limite superior do domínio pesado), com a máxima fase estável do lactato (MFEL, que disputa com VC a indexação do limite superior do domínio pesado) e com a caracterização dos domínios pesado e severo pelos parâmetros de cinética e amplitude do VO2. Em um primeiro estudo, 24 nadadores (16,5 ± 2,7 anos e 67,7 ± 13,5 kg) submeteram-se à estimativa da força de arrasto (Fr = A  v2). A Fr encontrada em máxima velocidade foi fracionada para compor quatro estágios de teste, com tempos de exaustão entre 3-20 min. em crawl-atado. A VC foi estimada empregando quatro distâncias entre 200-1500m. A potência crítica atada (PCAtada) linear (81,9W) e não linear (71,1W) não se diferenciaram (  0,05) dos valores de PC linear (108,2W) e não linear (96,3W) estimados por VC linear (1,2m.s-1) e não linear (1,14m.s-1), através da equação do desempenho. Neste primeiro estudo, pode-se concluir que PCAtada é correlata a VC, podendo representar a capacidade aeróbia. No segundo estudo, dez nadadores (16,6  1,4 anos e 69,8  9,5 kg) foram submetidos às estimativas de PCAtado (equações lineares e hiperbólica de 2-parâmetros), VC (ajuste linear do tempo pela velocidade nos desempenhos de 200, 400 e 800m), PAtadaMFEL (3 ou 4 esforços entre 95 a 105% da carga em PCAtada hiperbólica) e à vMFEL (3 ou 4 esforços entre 85 a 95% do velocidade máxima do crawl nos 400m)... / There is a lack of studies describing the domains of intensity in swimming, and few works approaches the P-tLim model in swimming. This study provided a way to assess the P-tLim model in swimming, applying the load controlled environment in full-tethered condition. The physiological meaning for the description of heavy and severe domains was established from the relationships of critical velocity (CV - upper boundary of heavy domain) to maximal lactate steady state (MLSS, conflicting with VC to demarcate the upper boundary of heavy domain), and from the descriptive characterization of kinetic and amplitude parameters of VO2. In he first study, 24 swimmers with 16.5 ± 2.7 years and 67.7 ± 13.5 kg were undertaken to drag force (Fr) estimation (Fr = A  v2). The Fr at maximal crawl velocity was the load that was fractioned to build the sets, lasting 3-20min until exhaustion. CV was calculated from distance between 200-1500m. The linear (81.9W) and non-linear (71.1W) PTethCrit were not different (  0.05) from the values of linear (108.2W) and non-linear (96.3W) PC estimative obtained from linear (1.2m.s-1) and non-linear (1.14m.s-1) CV through swim performance equation. It was conclude that PCTeth was related to CV, and reliable to indexes aerobic capacity. The second work, did analyze ten male swimmers (16.6  1.4 years and 69.8  9.5kg) that were submitted to the measurements of the CPTeth (linear and non-linear two parameters equation), CV (linear adjustment between time and velocity performance in the 200, 400 and 800m), PTethMLSS (3 or 4 trials ranging from 95 to 105% of the load at non-linear PCAtada), and vMLSS (3 or 4 trials ranging from 85 to 95% of the 400-m crawl performance). The results shown that neither CV (1.19  0.12m.s-1) nor the CPTeth (99.4  23.0W) matches the statements for MLSS, once differences were observed to the vMLSS (1.17  0.11m.s-1)... (Complete abstract click electronic access below)
36

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).
37

Chyby a jejich odstranění v plavecké technice plavců amatérů / Most common swimming technique mistakes by amateur swimmers and their re-education

Raček, Ondřej January 2016 (has links)
This thesis aims at observing the swimming technique of adult amateur swimmers and revealing their most common mistakes. Based on statistical analysis, a training plan was composed in order to eliminate the observed swimming technique errors. Furthermore, it was examined whether better swimming technique results in faster performance by the target group.
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Respostas biomecânicas e fisiológicas a diferentes frequências gestuais controladas na natação até a exaustão / Biomechanical and physiological responses at different controled stroke rates in swimming to exhaustion

Franken, Marcos January 2017 (has links)
O objetivo deste estudo foi descrever e analisar respostas agudas a diferentes frequências gestuais controladas do nado crawl em parâmetros biomecânicos, coordenativos e fisiológicos em intensidade relativa à velocidade de 95% da velocidade média de um teste de 400 m nado crawl, até a exaustão. Foram voluntários 12 nadadores do sexo masculino (idade: 23,6 ± 6,0 anos; estatura: 178,2 ± 4,5 cm; envergadura: 185,2 ± 4,9 cm; massa corporal total: 74,4 ± 8,9 kg) que treinavam, pelo menos, 12 horas por semana (melhor desempenho em 400 m nado crawl: 275,5 ± 16,2 s). Foram realizados: i) familiarização ao esnorquel, metrônomo, pacer e escala de 15 pontos de Borg; ii) determinação da velocidade média (V400) em teste máximo de 400 m (T400); iii) séries de nado contínuo a 95% da V400 em (a) Frequência gestual (FG) livre, (b) FG aumentada (110% da FG média da série de FG livre) e (c) FG reduzida (90% da FG média da série de FG livre). Foram avaliados: (i) parâmetros biomecânicos (frequência média de ciclos de braçadas - FG, distância média percorrida pelo corpo a cada ciclo de braçadas - DC, velocidade média de nado - VN; variação tridimensional intracíclica da velocidade do centro – VIV, VIVx, VIVy, VIVz, índice de coordenação - IdC, duração das fases de braçada – entrada + apoio, puxada, empurrada e recuperação; duração das fases propulsivas e não-propulsivas - FP e FNP; tempo propulsivo - Tprop) e eficiência de Froude ; e (ii) parâmetros fisiológicos (consumo de oxigênio – V̇O2, concentração sanguínea de lactato – [La], esforço percebido – EP), frequência cardíaca (FC) e amplitude (Ap), tempo de atraso (τd) e constante temporal (τ) (cinética do consumo de oxigênio) Dados foram obtidos antes, durante (momentos inicial, intermediário, final e pico) das séries de nado contínuo. Parâmetros biomecânicos de nado foram obtidos por cinemetria 3D. O V̇O2 foi mensurado respiração por respiração utilizando o ergoespirômetro K5 e esnorquel Aquatrainer (ambos Cosmed). Tempo total até a exautão, de cada série, foi também registrado. Foram utilizadas estatística descritiva e inferencial. Os princiapais achados indicaram que: i) entre as condições de FG, nadadores incrementam a VIV e a  com a FG controlada. Ao nadar com a FG aumentada, o IdC, a duração das fases de puxada e de empurrada e a FP aumentam e a constante temporal (τ) diminui. Já, ao nadar com a FG reduzida os valores do IdC, da duração da fase de recuperação e da FNP diminuem. Aumento ou redução da FG não alteram as respostas das demais variáveis fisiológicas e do tempo total até a exaustão (TTE). ii) Entre os momentos da FG livre, os nadadores aumentaram os valores da FG, da [La], do EP, da FC e do V̇O2 e diminuíram os valores da DC, da  e da VIVz. iii) Entre os momentos da FG aumentada, os nadadores diminuíram a VIV e a VIVx e aumentaram o Tprop, a [La], o EP, a FC e o V̇O2. iv Entre os momentos da FG reduzida, os nadadores diminuíram os valores do IdC, da VIV, da VIVx e da VIVz ao passo que aumentaram a , a [La], o EP, a FC e o V̇O2. Reduzir a FG, para a mesma velocidade, induz à diminuição da duração das fases não-propulsivas e à aumento da eficiência de Froude, enquanto as fases de puxada e de empurrada aumentam. A condição de FG aumentada diminuiu a constante temporal da cinética do consumo de oxigênio quando comparada às FG livre e reduzida. O controle da FG (com aumento de 10% e redução de 10%) durante o nado com velocidade controlada a 95% da V400 altera a magnitude dos parâmetros de braçada em ambas as situações. Enquanto a FG e a velocidade forem mantidas, as propriedades temporais do ciclo de braçada alteram características importantes para o desenvolvimento da técnica, da energética e consequentemente a melhora do desempenho dos nadadores. / The objective of this study was to describe and to analyze biomechanical, coordinative and physiological parameters acute responses to different control crawl frequencies in until exhaustion in intensity relative to the 95% speed of a 400 m front crawl test. Volunteered to this study 12 male swimmers (age: 23.6 ± 6.0 years; height: 178.2 ± 4.5 cm; upper arm span: 185.2 ± 4.9 cm; total body mass: 74.4 ± 8,9 kg) training at least 12 hours per week (best performance in 400 m front crawl: 275.5 ± 16.2 s). The procedures were: i) familiarization to the Borg's 15-point scale, snorkel, metronome and pacer; ii) determination of the mean velocity (V400) in a 400 m maximum front crawl test (T400); and iii) series in continuous swimming at 95% of the V400 at (a) free stroke frequency (FG); (b) increased FG (110% of the mean FG of the free FG series) and (c) reduced FG (90% of the mean FG of the free FG series. Biomechanical (mean stroke rate – FG, stroke length, swimming speed, swimming velocity tridimensional intracyclic variation - VIV, coordination index - IdC, duration of stroke phases - entry, pull, push and recovery, duration of propulsive and non-propulsive phases - FP and FNP, propulsive time - Tprop and Froude efficiency - ) as well as physiological parameters (oxygen consumption - V̇O2, lactate blood concentration - [La], perceived exertion - PE, heart rate (HR) and, regarding the oxygen uptake kinetics: amplitude - Ap, time delay (τd) and time constant - τ were obtained and assessed. Each series total time to exhaustion (TTE) was even registered. Data were obtained before, during (initial, intermediate, final and peak moments) of the continuous swimming series. Biomechanical swimming parameters were obtained by 3D cinemetry. The V̇O2 was measured breath-by-breath using the K5 ergometer and the Aquatrainer snorkel (both Cosmed). Descriptive and inferential statistics were used. The main findings indicated that: i) between the FG conditions, swimmers increase VIV and  with controlled FG. When swimming in increased FG, the IdC, the duration of the pull and push phases and the FP increase and the τ decreases. Already, when swimming in FG reduced the IdC, the duration of the recovery phase and the PNF decreased. Increasing or reducing FG does not alter the responses of the other physiological variables and the TTE. ii) Among the moments of free FG, swimmers increased the values of FG, [La], PE, HR and V̇O2 and decreased the values of DC,  and VIVz. iii) Among the moments of increased FG, swimmers decreased VIV and VIVx and increased Tprop, [La], PE, HR and V̇O2. iv) Among the moments of the reduced FG, swimmers decreased the values of IdC, VIV, VIVx and VIVz while increasing [La], EP, HR and V̇O2. Reducing FG at the same speed induces a decrease in the duration of non-propellant phases and an increase in Froude efficiency, while the pull and push phases increase. The increased FG condition decreased the τ when compared to free and reduced FG. The control of FG (10% increase and 10% reduction) during swimming at 95% V400 alters the magnitude of the stroke parameters in both situations. While FG and velocity are maintained, the temporal properties of the stroke cycle alter important characteristics for the development of the technique, energy and consequently the improvement of swimmers' performance.
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Efeitos de um treinamento combinado de força e natação na força muscular, aptidão cardiorrespiratória e desempenho de nado em indivíduos adultos

Prado, Alexandre Konig Garcia January 2017 (has links)
INTRODUÇÃO: No treinamento combinado (TC), a realização do treinamento aeróbio (TA) pode reduzir os ganhos de força e/ou potência decorrentes do treinamento de força (TF) quando ambos são realizados simultaneamente (efeito da interferência). O tipo de exercício aeróbio do TC tem sido investigado como possível fator determinante do efeito da interferência, porém não se sabe os efeitos do TC de força e natação na força muscular (FM). OBJETIVO: Analisar os efeitos do TF, treinamento de natação (TN) e TC de força e natação nas adaptações de FM, cardiorrespiratórias e desempenho de nado em adultos. MATERIAIS E MÉTODOS: 38 sujeitos de ambos os sexos foram randomicamente divididos nas condições TF (n=13; 29,5 ± 10,5 anos), TN (n=14; 30,71 ± 9,38 anos) e TC (n=11; 34,5 ± 9,8 anos). Destes, 14 participantes (29,2 ± 8,6 anos) realizaram um período controle (CON) de quatro semanas, previamente ao início do treinamento. O treinamento foi realizado três vezes por semana, durante 12 semanas. As avaliações da FM, aptidão cardiorrespiratória e desempenho de nado foram realizadas antes da condição CON (PRÉ-4), após condição CON/antes do treinamento (PRÉ0) e após treinamento (PÓS). As cargas do TF e volumes do TN entre os mesociclos de treinamento também foram comparados. Para a análise estatística foram utilizados procedimentos descritivos (média e desvio padrão) e teste de modelos mistos generalizados (GMM). RESULTADOS: Foi observado aumento significante (p<0,05) em todas as condições, sem diferença entre elas, para as variáveis de força dinâmica máxima (RM) de extensão de joelho (FMEJ), de extensão de cotovelo (FMEC) e resistência muscular localizada (RML) de extensão de cotovelos (RMLEC). Para as variáveis de RMLEJ e RM de extensão de ombro (FMEO) o aumento ocorreu apenas nas condições TF e TC, enquanto que a RML de extensão de ombro (RMLEO) só aumentou para o TN. Para a força isométrica, somente a força isométrica máxima de extensão de ombro, amentou significativamente nas condições TF e TC. A potência máxima em cicloergômetro aumentou apenas para o TF. As demais variáveis cardiorrespiratórias não se modificaram, com nenhum dos tipos de treinamento. Os tempos diminuíram e as velocidades de nado aumentaram em todas as distâncias, bem como a frequência de braçada (FB) nos 50 e 100 m e o índice de nado (IN) em 25 m aumentaram significativamente (p<0,05) para TC e TN, sem diferença entre as condições e nos 100 m o aumento ocorreu somente para o TC. Tanto no TN quanto no TF houve aumento significativo (p<0,05) dos volumes e cargas, respectivamente, entre os mesociclos, sem diferença entre as condições. CONCLUSÕES: Não há efeito da interferência nos ganhos de FM com o TC de força e natação. As variáveis cardiorrespiratórias não foram influenciadas por nenhum dos tipos de treino, porém aspectos relacionados à especificidade da medida podem ter afetado os resultados. A realização do TF associado a um TN parece não melhorar o desempenho de nado quando comparado ao TN isolado, em indivíduos adultos previamente destreinados. / INTRODUCTION: In combined training (CT), aerobic training (AT) can reduce strength and/or power gains resulting from strength training (ST) when both are simultaneously performed (interference effect). The type of aerobic exercise of the CT has been investigated as a possible determining factor of the interference effect, however the effects of the combined strength and swimming training on muscle strength (MS) are not known. OBJECTIVE: To analyze ST, swimming training (SW) and combined strength and swimming training effects on MS, cardiorespiratory and swimming performance adaptations in adults. MATERIALS AND METHODS: 38 subjects of both sexes were randomly divided into ST (n=13; 29.5 ± 10.5 years old), SW (n=14; 30.71 ± 9.38 years old) and CT (n=11; 34.5 ± 9.8 years old) conditions. Of them, 14 participants (29.2 ± 8.6 years old) performed a control period (COM) of four weeks, previously to the beginning of the training. The training was performed three times a week during 12 weeks. MS, cardiorespiratory fitness and swimming performance assessments were performed before CON condition (PRE-4), after CON condition/before training (PRE0) and after training (POST). ST loads and SW volumes between the training mesocycles were also compared. For statistical analysis, descriptive procedures (mean and standard deviation) and generalized mixed models (GMM) were used. RESULTS: a significant increase in all conditions were observed (p<0.05), without difference between them, for maximal dynamic strength (RM) of knee extension (RMKE), elbow extension (RMEE) and local muscular resistance (LMR) of elbow extension (LMREE) outcomes. For LMRKE and RM of shoulder extension (RMSE) outcomes, the increase only occurred in ST and CT conditions, whereas LMR of knee extension (LMRKE) only increased for SW. For isometric strength, only maximal isometric strength of knee extension significantly increased in ST and CT conditions. Maximal power in cycle ergometer only increased for ST. The other cardiorespiratory variables were not modified, with none of the training types. Swimming times decreased and swimming speeds increased in all distances, as well as stroke frequency (SF) in 50 and 100 m and index of swimming (IS) in 25 m significantly increased (p<0.05) for CT and SW, without difference between conditions, and in 100 m the increase only occurred for CT. In both SW and ST there was a significant increase (p<0.05) of the volumes and loads, respectively, between the mesocycles, without difference between the conditions. CONCLUSIONS: There is not an interference effect in MS gains with combined strength and swimming training. Cardiorespiratory outcomes were not influenced by any of the training types; nevertheless, aspects related to measurement specificity could have affected the results. The performance of ST associated to a SW does not seem to improve swimming performance when compared to isolated SW, in previously untrained adult individuals.
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Vliv posilovacího cvičení na Biokineticu do plaveckého výkonu na 50 m kraul / Effect of strengthening exercises on Biokinetic to swimming performance at 50 m crawl

Nezdara, Jaroslav January 2019 (has links)
Title: Effect of strengthening exercises on Biokinetic to swimming performance at 50 m crawl. Objectives: The aim of this work is to find out whether a two-month movement intervention performed on a swimming simulator (Biokinetic) will affect the swimming performance of a 50 m crawl by FTVS students. Methods: Five probands of the 2nd year of the follow-up study at Charles University FTVS participated in the research. The anthropometric data were obtained using the TANITA testing device. To determine the maximum endurance muscle strength of the upper limbs and other movement parameters, we used the Biokinetic device. In order to determine the maximum swimming performance, we carried out a swimming test for 50 m with the crawl technique. Interest activities were identified through a questionnaire. Data were analyzed by MS EXCEL and NCSS 2019. Results:The results show, that the Biokinetic weight training exercises had a positive influence on swimming performance at a distance of 50 m crawl in swimming pool. In the analysis of the technique of performing motion shots on Biokinetic, we found an increase in the frame frequency, but a decrease in the overall path. The increased in frequency according to our findings results in a reduction of the total path of the motion cycles. All probands experienced an...

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