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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.
281

Análise biomecânica do ombro de nadadores após a realização de um teste de esforço máximo / Biomechanical analysis of the swimmers\'s shoulder after performing a maximal effort test

Serenza, Felipe de Souza 18 April 2017 (has links)
A prevalência de dor no ombro em nadadores competitivos pode chegar a 91%. A articulação escapulotorácica (ET) tem papel central na funcionalidade do ombro atuando de forma coordenada com a articulação glenoumeral (GU), posicionando a cavidade glenóide para evitar impacto precoce do manguito rotador (MR) sob o arco coracoacromial. Um atleta de natação pode realizar até 2500 braçadas em apenas um dia de treinamento o que os torna susceptível a fadiga. O objetivo deste estudo foi analisar a cinemática da escápula e atividade eletromiográfica dos músculos trapézio ascendente (TA), trapézio transverso (TT), trapézio descendente (TD) e serrátil anterior (SA) em nadadores antes e após a realização de um teste de esforço máximo de 3 minutos. O estudo contou com 16 atletas entre 15 a 24 anos. Um sistema de 8 câmeras infravermelho foi utilizado para registrar a cinemática nos três planos de movimento antes e após o teste de esforço. Foi utilizado um eletromiógrafo com sensores wireless sincronizado ao sistema de câmeras. A análise estatística para comparação entre o pré e pós teste foi realizada pelo teste t pareado e a estimativa do tamanho do efeito (TE) foi calculada pelo d Cohen\'s. Foram realizadas regressões lineares para verificar a relação entre a variação cinemática e a variação eletromiográfica. Os resultados mostraram aumento da rotação interna da escápula em todas as angulações com TE pequeno, e aumento da inclinação anterior com 120° de elevação com TE pequeno. O SA apresentou diminuição da atividade eletromiográfica nos intervalos de 120-90° e 60-30° com TE moderado. Houve relação entre a variação da inclinação anterior da escápula e a variação da atividade muscular do TT, da rotação interna com a variação do TT e do SA. Concluiu-se que atletas de natação submetidos a um teste de esforço máximo exibem aumento da inclinação anterior, além de aumento da rotação interna durante toda a ADM. A atividade muscular do SA decaiu após o teste de esforço máximo. Por se tratar de um músculo atuante durante todo o gesto esportivo, estratégias preventivas e de tratamento devem focar no ganho de força e resistência deste músculo. / The prevalence of shoulder pain in competitive swimmers may reach 91%. The scapulothoracic joint (ST) plays a central role in shoulder function acting in a coordinated way with the glenohumeral joint (GU), avoiding the impact on the rotator cuff (MR) under the coracoacromial arch. A swimming athlete can perform up to 2.500 strokes in just one day of training which makes them susceptible to fatigue. The aim of this study was to analyze the scapular kinematics and the electromyographic activity of the upper trapezius (UT), medium trapezius (MT), lower trapezius (LT) and anterior serratus (AS) muscles in swimmers before and after a maximal effort in a 3 minutes test. The study included 16 athletes aged between 15 and 24 years. A system with 8 infrared camera was used to verify the kinematics in the three planes of motion before and after the effort test. A wireless electromyograph synchronized with the camera system was used. The statistical analysis for comparison between the pre and post test was performed by the paired T-test and the effect size calculation (ES) was performed by d Cohen\'s. Linear regressions were performed to verify the relationship between the kinematic variation and the electromyographic variation. The results showed increased scapular\'s internal rotation at all angles with small ES and anterior tilt increase at 120° elevation with small ES. The AS showed a decrease in electromyographic activity in the intervals of 120-90° and 60-30 ° with moderate ES. There was a relation between the variation of the anterior tilt of the scapula and the variation of the MT muscle activity, between the internal rotation with the MT and between the internal rotation with AS muscle variation. Was concluded that swimming athletes submitted to a maximal effort test showed an increase in anterior tilt, in addition to an increase in internal rotation throughout all the range of motion. The AS muscle activity declined after the maximal effort test. Because it is a active muscle throughout the stroke movement, preventive and treatment strategies should focus on the strength and endurance of this muscle.
282

Fluid dynamic research on polychaete worm, Nereis diversicolor and its biomimetic applications

Yang, Ruitao January 2012 (has links)
This thesis is a study of the swimming locomotion of the polychaete worm, Nereis diversicolor. Previous research has shown that there are two distinct jet-like flow regions in the wake of a swimming polychaete worm (Hesselberg 2006). In the first section of this thesis, this flow pattern is studied in greater detail using a high resolution particle image velocimetry (PIV) technique. A small region close to the wave crest of the undulating worm is recorded and the fluid velocity vector fields are plotted. The close-up PIV results show how the jet-like fluid pattern is formed due to the action both of a single sweeping parapodium and to the interaction between adjacent parapodia, proving for the first time that Gray’s (1939) explanation of the propulsion mechanics is in fact correct. The second part of this thesis is focused on the pumping action of the polychaete worm, a behaviour adopted by the worms to create a flow of nutrients through their burrows. Particle image velocimetry (PIV) experiments were performed on tethered polychaete worms, Nereis diversicolor. The tethered worms moved in a gait which was different from that of freely swimming ones. They used a much smaller body wave amplitude, pumping liquid with very high efficiency by cooperative movement of their body and parapodia. In the third part of the thesis, a mechanical model was designed and built. The model consisted of a series of paddle units. Each paddle was driven by a servo motor. Breugem (2008) did a CFD simulation of the paddle model. Similar fluid patterns were generated by the physical model. Reversed flow was found at low Reynolds number (Re) and higher Re situations. The flow direction could be controlled by simply adjusting the beating frequency of paddles. The mechanical model is not sufficient to mimic the pumping locomotion of the worms due to absence of an undulatory movement. The pumping efficiency is low compared to pumping worms.
283

A comparison of biomechanical and physiological characteristics between front crawl and back crawl

Gonjo, Tomohiro January 2016 (has links)
Front crawl (FC) and back crawl (BC) are similar in terms of having alternating contributions of the arms combined with a six beat kick. However, the reason for the faster swimming times of FC than BC has not yet been established. There have been several studies in which the energy expenditure (Ė) of FC and BC were investigated. However, few researchers have compared Ė between the strokes. Also, although there have been some studies for FC using 3D motion analysis, few researchers have applied 3D motion analysis for BC. There have also been some studies in which the relationship between isokinetic torque produced on an isokinetic dynamometer and FC performance has been investigated, however, the relationship between isokinetic torque and BC performance is unclear. Therefore, the aim of this study was to determine why FC is faster than BC by investigating physiological and biomechanical differences between FC and BC. Ten Portuguese male national level swimmers were recruited for this study. Three studies were conducted to achieve the aim. In the first study, Ė of FC and BC at the same testing speed below the anaerobic threshold were investigated by measuring swimmers’ oxygen uptake. Kinematic variables of FC and BC below the anaerobic threshold were also measured by 3D motion analysis in the first study. In the second study, 3D motion kinematics of FC and BC at the same selected speeds were investigated. In the third study, kinematic differences between FC and BC at the same exercise intensities, and correlations between the kinematics and isokinetic muscular torques of the swimmer in FC and BC and their differences were assessed. Below the anaerobic threshold, Ė of the swimmers in BC was significantly greater than that in FC at the same speed although there were no differences in stroke frequency (SF), stroke length (SL) and stroke index (SI). Swimmers also had significantly higher Froude efficiency (ηF) in FC than in BC. Differences in several kinematic variables (range of motion of the foot, duration of non-propulsive phases, and intra-cycle velocity variation) suggested that swimmers expended greater energy in BC than in FC. Differences in other kinematic variables (body roll angle, hand speed/acceleration, yaw angle fluctuation, centre of mass displacement, and hand/foot displacements) suggested the possibility of resistive impulse being larger in BC than in FC during the stroke cycle. Thus, FC is more economical and efficient than BC because swimmers lose less energy to the water during the non-propulsive phase, and possibly have smaller resistive impulse in FC than in BC at speeds below the anaerobic threshold. At the same selected speeds above the anaerobic threshold, ηF in BC was significantly lower than that in FC, which was due to faster mean 3D hand speed during the stroke cycle in BC than in FC. The faster mean hand speed in BC than in FC was due to the faster 3D hand speed during the pull phase, and longer relative duration of the release and above-water phases in BC than in FC. SI was also larger in FC than in BC, which was due to longer SL in FC than in BC. The longer SL in FC than in BC was due to the longer duration of propulsive phases and probably smaller resistive impulse during the stroke cycle in FC than in BC. At the same selected exercise intensities, FC was faster than BC because of higher SF. The higher SF in FC than in BC was due to the longer duration of the above-water phase in BC than in FC, longer hand path distance during non-propulsive phases in BC than in FC, earlier timing of the hand entry in relation to the underwater phase of the other hand in FC than in BC. SF in both FC and BC was significantly correlated with shoulder adduction isokinetic torque of the swimmers, however, the effect of shoulder isokinetic torque on the difference in swimming performance between FC and BC required further investigation. In conclusion, FC is faster than BC because swimmers can achieve higher SF in FC than in BC, and FC is more economical and efficient than in BC with indirect evidence that resistive force are greater in BC than in FC.
284

Avaliação fisiológica e biomecânica de surfistas recreacionais

Godoy, Daniel Fagundes January 2017 (has links)
Considerando as similaridades entre o nado crawl e a remada executada por surfistas, além da preparação física executada pelos mesmos em piscina, este trabalho objetivou avaliar surfistas recreacionais por meio da comparação, concordância e correlação das variáveis fisiológicas e biomecânicas obtidas a partir de testes nadando crawl e remando com prancha. Foram avaliados 14 surfistas (idade de 37,7 ± 4,7 anos) em duas situações: (i) teste em nado crawl, máximo, de 300 m e (ii) teste de remada, nas mesmas condições de intensidade e duração do teste de nado crawl. Os testes foram realizados na mesma piscina e nas mesmas condições de temperaturas e horário. Foram avaliados: consumo de oxigênio de pico (VO2pico) durante os testes, frequência cardíaca (Fcard), concentração sanguínea de lactato ([LA]), esforço percebido (EP) e cinemática em ambos os testes. Dentre os resultados: para teste de nado crawl e teste de remada respectivamente, destacam-se os resultados de VO2pico, Fcard, [LA], e EP: 38,5 ± 5,3 e 36,2 ± 5,3 ml.kg-1.min-1; 149,6 ± 17,4 e 162,2 ± 14,6 bpm; 10,4 ± 2,7 e 12,1 ± 2,7 mmol.l-1; e 16,1 ± 2,4 e 16,7 ± 1,4 pontos. As velocidades médias dos testes foram de, respectivamente, para teste de nado crawl e teste de remada: 0,91 ± 0,1 e 1,27 ± 0,1 m-s-1. De modo geral, os testes apresentaram resultados similares, com baixa concordância, alta correlação e de médios a grandes tamanhos de efeito entre nadar e remar. Considerando os resultados encontrados, o treinamento de surfistas, em piscina, não deveria ser apenas com natação. Conclui-se que os esforços e testes (nadar crawl e remar) não são plenamente intercambiáveis. / Considering the similarities between the front-crawl and the paddling movement, in addition to the physical preparation performed by surfers in swimming pool, this work aimed to compare, to test the agreement and to correlate surfers’ values of oxygen uptake obtained from swimming and paddling tests. A total of 14 surfers (age 37.7 ± 4.7 years) were evaluated in two situations: (i) a 300 m maximum front-crawl test (ii) a paddling test in the same conditions of intensity and duration of the swimming test. The tests were performed in the same pool and under the same conditions of temperatures and time of the day. Peak oxygen uptake (VO2peak) during the tests, heart rate (Fcard), blood lactate concentration ([LA]), perceived exertion (PE) and kinematics in both tests were assessed. Among the results, VO2peak, Fcard, [LA], and EP were, respectively for front-crawl and paddling test:: 38.5 ± 5.3 and 36.2 ± 5.3 ml.kg-1.min-1; 149.6 ± 17.4 and 162.2 ± 14.6 bpm; 10.4 ± 2.7 and 12.1 ± 2.7 mmol.l-1; and 16.1 ± 2.4 and 16.7 ± 1.4 points. The mean velocities of the tests were, respectively, for front-crawl test and paddling test: 0.91 ± 0.1 and 1.27 ± 0.1 m.s-1. In general, the tests presented similar results, with low agreement, high correlation, and medium to large effect sizes between swimming and paddling. Considering the results, the training of surfers, in swimming pool, should not be just with swimming. It is concluded that the efforts and tests (front-crawl and the paddling movement) are not fully interchangeable.
285

Parâmetros antropométricos, fisiológicos e biomecânicos de nadadores em teste de 400m nado crawl : comparações e correlações

Correia, Ricardo de Assis January 2016 (has links)
Introdução e Objetivos: considerando a complexidade da natação, o objetivo geral desta dissertação foi investigar o desempenho em 400 m nado crawl (T400), a partir de parâmetros antropométricos, biomecânicos e fisiológicos. Materiais e Métodos: O estudo foi avaliado e aprovado pelo Comitê de Ética em Pesquisa da UFRGS. Participaram 14 nadadores competitivos (21,2 ± 4,15 anos de idade) de nível regional e nacional, que foram avaliados em relação à: (i) antropometria e somatotipo; (ii) parâmetros biomecânicos (frequência média de ciclos de braçadas - FB, distância média percorrida pelo corpo a cada ciclo de braçadas - DB, velocidade média de nado - VN; variação intracíclica da velocidade do centro de massa nos três eixos - VIVx, VIVy, VIVz, índice de coordenação - IdC, duração das fases propulsivas e não propulsivas - Fprop e Fnprop, e tempo propulsivo - Tprop); e (iii) parâmetros fisiológicos (consumo de oxigênio – VO2, concentração sanguínea de lactato – [LA], e percepção subjetiva de esforço – PSE). Dados foram obtidos antes, durante (M1, M2, M3 e M4) e após o T400. Parâmetros biomecânicos de nado foram obtidos por cinemetria 3D e método e-zone para cálculo da localização do centro de massa. VO2 foi mensurado respiração por respiração utilizando o ergoespirômetro K5 e esnorquel Aquatrainer (ambos Cosmed). Foi utilizada estatística descritiva e inferencial (comparativa e correlacional). Resultados: (i) nadadores de 400 m possuem somatotipo meso-ectomórfico; (ii) não houve mudanças nos parâmetros biomecânicos ao longo do teste (exceto maior FB no M4); (iii) o VO2 do M1 foi o menor em comparação a M2, M3 e M4, sendo que o maior valor de VO2 (pico: 67,6 ± 8,9 ml·kg-1·min-1) foi identificado nos últimos trechos do T400; após o termino do teste a [LA] foi de 9,03 ± 0,04 mmol.l-1 e PSE de 17,6 ± 1,2 pontos. Entre as variáveis fisiológicas, a [LA] correlacionou-se inversamente com o desempenho (r = -0,61). Conclusão: Nadadores incrementam a FB ao fim do teste, buscando, pelo menos, incrementar a VN. Mesmo que a VN tenha se mantido constante, os maiores valores foram encontrados ao final do teste. Ao mesmo tempo, o consumo de oxigênio incrementou no último quarto do teste, possivelmente de acordo com o aumento da FB. / Introduction and Objectives: considering the swimming complexity, the general objective of this study was to investigate the performance in 400 m front crawl (T400) with anthropometric, biochemical and physiological parameters. Materials and Methods: the Ethics Committee of the UFRGS approved the study. Fourteen competitive swimmers (21.2 ± 4.15 years old) of regional and national level were assessed in relation to: (i) anthropometry and somatotype; (ii) biomechanical parameters (mean rate of stroke cycles - SR, mean stroke length - SL, mean swimming speed - SS; center of mass intracyclic velocity variation in the three axes - VIVx, VIVy, VIVz; index of coordination - IdC, duration of the propulsive and non-propulsive phases - Fprop and Fnprop; and propulsive time - Tprop); and (iii) physiological parameters (oxygen consumption - VO2, blood lactate concentration - [LA], and perceived exertion - PE). Data were obtained before, during (M1, M2, M3 and M4) and after T400. Biomechanical parameters of swimming were obtained by kinematics and 3D method e-zone for calculating the center of mass location. VO2 was breath-by-breath measured using the K5 ergospirometer and snorkels Aquatrainer (both Cosmed). It used descriptive and inferential statistics (comparative and correlational). Results: (i) 400 m swimmers are meso-ectomorphic somatotype; (ii) no changes in biomechanical parameters during the test (except increased SR in the M4); (iii) VO2 in the M1 was lower when compared to M2, M3 and M4, and the largest VO2 value (peak: 67.6 ± 8.9 ml·kg-1·min-1) was identified in the last T400 part; after the end of the test the [LA] was 9.03 ± 0.04 mmol·l-1 and PE was17.6 ± 1.2 points. Among the physiological variables, [LA] correlated inversely with performance (r = -0.61). Conclusion: Swimmers increase SR in the end of the test, seeking, at least, to increase the SS. Even the VN has remained constant, the highest values were found at the end of testing. At the same time, the increased VO2 in the last in the T400’s final part possibly is in accordance with the SR increased.
286

Resposta à ingestão do tucumã (Astrocaryum aculeatum Meyer) no tratamento da dislipidemia induzida por dieta em ratos Wistar sedentários e exercitados

Maia, Geórgia Craveiro Holanda Malveira 21 May 2013 (has links)
Made available in DSpace on 2015-04-11T13:38:30Z (GMT). No. of bitstreams: 1 Capa da Dissertacao Georgia.pdf: 241136 bytes, checksum: 26172cab25063b953eff0455c1729780 (MD5) Previous issue date: 2013-05-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Lipid disorders are related to the development of cardiovascular and cerebrovascular diseases and therefore is considered an important risk factor that can be treated by drugs or even with changes in eating habits and physical. The result is a tucumã regional physico-chemical features important for the treatment of dyslipidemia, such as substantial concentration of fibers. Thus, the present study aims to conduct in vivo study in rats untrained and trained on the use of tucumã the Amazons in the treatment of diet-induced dyslipidemia. Was performed for both the induction of dyslipidemia followed by treatment with a base ration tucumã with or without swimming. We used 40 male rats weighing about 350 grams. These animals were divided into 4 groups of 10 animals forming the Sedentary Control Group (SCG) the exercised control group (GCE), the Group Treatment Sedentary (GTS) and Treatment Group exercised (GTE). It is the body mass gain, feed intake, plasma concentrations of cholesterol, triglycerides, HDL-C, LDL-C, VLDL, total protein, and the hormones insulin and leptin. The GCE group showed a tendency to higher food consumption and the groups that consumed the flesh of the fruit tucumã showed a trend to a higher body mass gain. The descriptive analysis showed that the groups that consumed the diet increased the fruit tucumã showed a trend to a higher body mass gain. The GCE has a tendency to higher plasma cholesterol, as well as the GTE GTS and have higher absolute values for triglycerides and VLDL-C HDL lipids and LDL-C were shown to be elevated in the group that consumed tucumã. Through research it can be seen that the fruit tucumã (Meyer Astrocatyum aculeatum) hypolipidemic has no effect, since the animals had elevated concentrations of lipid / As dislipidemias estão relacionadas ao desenvolvimento de doenças cardiovasculares e cerebrovasculares e, portanto, é considerado um fator de risco importante que pode ser tratado através de fármacos ou mesmo com mudanças nos hábitos alimentares e físicos. O tucumã é um fruto regional que apresenta características físico-químicas importantes para o tratamento das dislipidemias, como a concentração considerável de fibras. Diante disso, o presente estudo tem como objetivo realizar o estudo experimental in vivo em ratos Wistar sedentários e exercitados sobre o consumo de tucumã do amazonas no tratamento da dislipidemia induzida por dieta. Para tanto foi realizado a indução da dislipidemia seguido do tratamento com ração a base de tucumã associado ou não a natação. Foram utilizados 40 ratos machos pesando em média 350 gramas. Esses animais foram divididos em 4 grupos com 10 animais formando o Grupo Controle Sedentário (GCS) o Grupo Controle Exercitado (GCE), o Grupo Tratamento Sedentário (GTS) e o Grupo Tratamento Exercitado (GTE). Verificou-se o ganho de massa corporal, consumo de ração, a concentração plasmática de colesterol, triglicerídeos, HDL-c, LDL-c, VLDL, proteínas totais, além dos hormônios insulina e leptina. O grupo GCE apresentou tendência ao maior consumo alimentar e os grupos que consumiram a polpa do fruto tucumã apresentaram uma tendência ao maior ganho de massa corporal. A análise descritiva demonstrou que os grupos que consumiram a dieta acrescida do fruto tucumã apresentaram uma tendência ao maior ganho de massa corporal. O grupo GCE apresenta uma propensão a maior concentração plasmática do colesterol, assim como os GTS e GTE apresentam maiores valores absolutos para os triglicerídeos e para o VLDL Os lipídios HDL-c e LDL-c mostraram-se elevados nos grupos que consumiram tucumã. Através da pesquisa realizada pode-se observar que o fruto tucumã (Astrocatyum aculeatum Meyer) não apresenta efeito hipolipidêmico, visto que os animais apresentaram concentrações elevadas dos lipídeos
287

Determinação da contribuição anaeróbia durante o desempenho do nado crawl em distâncias curtas e médias-curtas, entre homens e mulheres /

Bravo, Valter Akira. January 2018 (has links)
Orientador: Dalton Muller Pessoa Filho / Banca: Marcelo Papoti / Banca: Alessandro Moura Zagatto / Resumo: Está bem estabelecido que a contribuição glicolítica anaeróbia é predominante nos eventos próximos a 50 e 100 metros, e que a contribuição aláctica alcança sua maior capacidade de contribuição próximos aos 50 metros. Todavia, pode-se questionar se a taxa de ajuste do metabolismo anaeróbio não seria mais apropriada para analisar os desempenhos de curta duração (50 e 100 metros), ao invés da demanda total. Bem como, pouco se sabe se AOD e as demandas de cada metabolismo (láctico vs. aláctico vs aeróbio) tendem a apresentar respostas diferentes entre sexos. Assim, o objetivo do presente estudo foi analisar o déficit acumulado de oxigênio (AOD) nos desempenhos do crawl em distâncias de 50, 100 e 200 metros, comparando-o pelo método da variação da resposta lactacidêmica e perfil aláctico da curva de débito oxigênio. Participaram deste estudo 12 (doze) nadadores homens (16,8 ± 2,2 anos, 179,3 ± 7,0 cm e 69,4 ± 7,8 kg) e 10 (dez) nadadoras (15,5 ± 3 anos, 161,8 ± 6,2 cm e 55,5 ± 6,8 kg). Todos realizaram o desempenho máximo para as distâncias de 50, 100 e 200 metros para a determinação do O2 acumulado. Após 24 horas, os nadadores desempenharam um teste incremental escalonado máximo e descontínuo (TIE: 6x250m e 1x200m, 50 a 100% da v200m) para a avaliação do V̇O2max e obtenção da relação V̇O2 vs. velocidade de nado em intensidades submáximas. A partir desta relação, projetou-se a demanda de O2 nas velocidades correspondentes ao 50, 100 e 200m foi estimada. Em seguida, a permuta gasos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: It is well established that the anaerobic glycolytic contribution is predominant in events close to 50 and 100 meters, and that the alactic contribution reaches its greatest capacity of contribution close to 50 meters. However, one question that needs to be asked is whether a rate of anaerobic metabolism adjustment is no longer useful for analyzing short-term performance (50 and 100 meters), as opposed to total demand. As well as, little is known if AOD and the demands of each metabolism (lactic vs. alactic vs aerobic) tend to present different responses between genders. Thus, the objective of the present study was to analyze the accumulated oxygen deficit (AOD) in crawl performance at distances of 50, 100 and 200 meters, comparing it by the lactacidemic response and alactic profile of the recovery curve Twelve (12) male swimmers (16.8 ± 2.2 years, 179.3 ± 7.0 cm and 69.4 ± 7.8 kg) and 10 (ten) female swimmers (15.5 ± 3 years old, 161.8 ± 6.2 cm and 55.5 ± 6.8 kg)) participated in this study. All participants were performed a maximal effort at 3 distances (50, 100 and 200 meters) for the determination of accumulated O2 After 24 hours, swimmers performed a maximum and discontinuous step incremental test (TIE: 6x250m and 1x200m, 50 to 100% of v200m) for an evaluation of V̇O2max and obtaining the VO2 vs. swimming speed relationship. From this relation, the demand for O2 at the velocities corresponding to 50, 100 and 200m was estimated. Then, gas exchange was also analyzed during... (Complete abstract click electronic access below) / Mestre
288

The greatest Olympian of all-time? The ideological implications of celebrating Michael Phelps

Hodler, Matthew Ross 01 May 2016 (has links)
On August 4, 2012, white American swimmer Michael Phelps was awarded a Lifetime Achievement Award by the international swimming federation in recognition of his Olympic achievements. The unprecedented award – a specially commissioned sculpture – proclaimed Phelps as “the greatest Olympian of All Time.” This title may, at one level, be perceived as a benign honorific bestowed upon an extra-ordinary athlete. On another level, the title should be viewed as a result of the hidden ideological work done by and through discourses of swimming in America, discourses that are always racialized, classed, nationalized, and gendered. Michael Phelps is the point of entry to unpack how modern sport and the Olympics reproduce these dominant views and processes that lead to contemporary social inequalities. My focus is an examination of the power relations that enabled and produced him as the Greatest Olympian of All-Time. Phelps’s phenomenal performance in the pool is undeniable, but I argue that the ensuing adulation and recognition results as much from his privileged position as a white American man as from his hard work, skill, and determination. This dissertation unpacks and explains how these processes work in the contemporary sporting world. Scholars have long argued that sport is a site for understanding how race, class, gender, and nationalisms are performed and/or constructed. In this dissertation, I take a critical cultural studies approach to demonstrate that, from an ideological and cultural point of view, Michael Phelps is the greatest Olympian of all time because he is the physical and symbolic embodiment of the modern Olympic movement, a movement founded upon 19th century ideals of humanism, liberalism, and modernity that continues to stabilize and reinforce dominant views of race, gender, class, nationalism and sexuality. To make this argument, I first historicize the sport of swimming itself. As one of the sports at the first Modern Olympics in 1896, swimming is an ideal site for understanding the modernization process through sport. Swimming has long been dominated by white athletes, and I deploy the recent concept of the sporting racial project to grasp how modernization is a racialized project fundamental to constructions of institutional racism. Next, I examine media representations of Michael Phelps in the early 21st century. These representations reveal the role of sport in popular imaginations of the nation and, specifically, the importance of the white male sporting hero in constructions of America in the post-9/11 world. Then, I explore and contextualize notions and meanings of “amateur” and “eligibility” within late 20th and early 21st century structures of Olympic swimming, including the complex and contradictory relationships between inter/national governing bodies. Finally, I show how these three seemingly independent processes involving race, class, gender, and nation are interdependent and fundamental to modern sport and the Olympics.
289

Acquisition and Analysis of Aquatic Stroke Data From an Accelerometer Based System

Davey, Neil P., n/a January 2004 (has links)
The aim of this work was to develop devices for elite athletes to record performance related parameters during their training. A device was initially designed and built for rowing to record the motion of the boat. This was to gain understanding of motion signals in a one dimensional plane. The device uses a iPAQ handheld computer for recording and display of data to the user. Using the knowledge obtained from the accelerometer data of the rowing system an initial prototype device was designed and constructed for use in swimming. This device was required to be wearable whilst the swimmer was training, thus it had to record the data onboard. A second version of the swimming device was constructed to improve the usability of the device. The swimming device has fully sealed electronics, wireless charging and infrared communications. The device records three dimensional acceleration patterns at 150Hz, and can store over 6 hours of data using the internal memory. The device can operate for greater than 12 hours before needing to be recharged. The data collected from the swimming device was used to develop processing algorithms to extract when the swimmers push off from the wall, the type of stroke they are swimming, and for freestyle the stroke count. The results of the wall push off algorithm were compared against manual hand timing with 90% algorithm results being with ±1 second of the hand timing data. The stroke type identification algorithm determines which stroke is being swum and presently has an accuracy of 95%. The results of the freestyle stroke count algorithm were compared against manual stroke counts from raw accelerometers data and underwater video. Of the 164 data sets analysed over 90% of the algorithm results were within ±1 strokes of the manual recorded stroke counts.
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Fluid forces on an accelerating hand in swimming

Kudo, Shigetada, n/a January 2007 (has links)
This study examines the effects of acceleration on fluid forces acting on the hand in swimming and presents a new pressure method to predict fluid forces acting on the accelerating hand. Swimmers and coaches require accurate information about swimmers� fluid forces, propulsion and drag, in order to improve performance. In general, swimmers are likely to generate propulsion mainly with their hands in the front crawl stroke, butterfly and back crawl stroke. Researchers have attempted to estimate the fluid forces on the hands with various techniques including a cinematographic method (a "quasi-static" approach), a pressure method and a numerical method of computational fluid dynamics. However, the effect of accelerations on fluid forces acting on the hand has not yet been well quantified. Understanding of the effect of acceleration on fluid forces on the hand can provide useful information to enhance swimming performance. Also the developments of a method to predict fluid forces acting on the accelerating hand in swimming can be used to evaluate swimming performance more accurately. The present study used a hand model attached to a load cell to measure forces in three orthogonal directions and pressure sensors to measure pressures on the hand model rotated in the flume. The model position was measured by a potentiometer fixed to the axis of the model rotation. The quantification of the effect of acceleration was based on a simple theoretical understanding for fluid mechanics, using the inertia coefficients and the coefficients of fluid forces, that is widely accepted in other disciplines. The quantification was focused mainly in the direction tangential to the model rotation because the magnitude of the velocity changed in this direction. The overall effect of acceleration on fluid forces on the hand model was that the inertia coefficients increased rapidly in the early phase of the model movement, then in the final deceleration phase of model movement the inertia coefficients decreased to a negative value and then became small. The inertia coefficient increased in the impulsive start of the hand model, indicating that fluid forces acting on the hand increased as accelerations of the hand increased. This result was consistent with the simple theoretical understanding to induce additional fluid forces on the hand, that is, fluid forces on the hand increased as accelerations increased. However, the inertia coefficient decreased and reached large negative values in the late phase of the model movement involving decelerated motion, indicating that fluid forces on the hand increased as acceleration of the hand decreased to negative values (decelerations). That result was not consistent with the simple theoretical understanding to induce additional fluid forces on the hand because the simple theoretical understanding cannot take account of the preceding history of the fluid motion around the hand model associated with the formation of vortices. Thus, more sophisticated theory is needed. The dynamic pressure measured by the pressure sensors implied that the induced fluid forces might be due to large attached vortices behind the hand model. The hand was considered as a blunt body when the angle of attack was large (maximum = 90�) and an aerofoil shape when the angle of attack was small. The inertia coefficients became large when the hand model was set at the large angles of attack, indicating that the effect of accelerations on the hand model increased when the hand surface was directed to the on-coming flows (blunt body). For the development of the new pressure method, a regression analysis was used to build a single best-fit equation to predict fluid forces acting on the accelerating hand model. The single best-fit equation was acquired for various orientations of the hand model. The accuracy of prediction of fluid forces acting on the accelerating hand model was checked by a root mean square (RMS) difference. The RMS difference by the pressure method was approximately half of the RMS difference by the "quasi-static" approach that has been a major method to predict fluid forces exerted by the hand in swimming. The present study has quantified the effect of acceleration on fluid forces acting on the hand in swimming and developed a new pressure method including acceleration effects to predict fluid forces acting on the accelerating hand.

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