Background: Maximal muscle strength and body proportions are some of the key attributes to be a fast swimmer. Even though dolphin kick (DK) has become essential to be a fast swimmer little is known of its associations to muscle strength and body proportions. Moreover, the effect of feet size has been stated to be a primary contributor to dolphin kick thrust production, but scientific evidence is still scarce. Aim: The aim of this study was to examine the correlation between lower extremity muscle strength, abdominal strength and feet length with dolphin kick performance over 15 meters in active competitive swimmers 15-20 years old Method: Twelve Test subjects (six male and six female) participated. Test subjects performed four 15 meters dolphin kick trials. Lower extremity muscle strength was tested with a three repetition maximum strength test and abdominal strength with brutal bench test. The muscles tested were rectus femoris, biceps femoris and rectus abdominis. Feet length was measured with a measuring tape. The correlations between lower extremity strength, abdominal strength and feet length with dolphin kick performance were calculated with spearman’s correlation. Results: Twelve test subjects between ages 15-20 years old participated. Spearman correlation test showed that lower extremity strength (rectus femoris: rs=-0.57 and biceps femoris: rs=-0.66) had a large association with dolphin kick performance. Abdominal strength (rs=-0.46) and feet length (rs=-0.35) had a moderate association with dolphin kick performance. Conclusion: The present study conclude that lower extremity strength is important for DK performance over 15 meters and that abdominal strength and feet length also is important but is less associated to it. The finding from this study can be used for making training programs for improving DK performance and for scouting swimmers with beneficial traits for specific swimming technique.

Made available in DSpace on 2016-12-06T17:07:01Z (GMT). No. of bitstreams: 1 MARCELO PINTO.pdf: 1198069 bytes, checksum: d0bf83a097faa213dc8b92cbbf92f219 (MD5) Previous issue date: 2014-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / To understand the factors that affect the capability of fast swimming is crucial to obtain success in the sport. The underwater dolphin kick UDK - has a great balance between minimize the drag and maximize the forward impulse, reducing the physical effort of the swimmer. Thus, to know the elements that compound the UDK, like frequency, force, angles and amplitudes of kicking lead to a better understanding that feature of swimming is one of the factors that most compromise the swimming time. The aim of this work was to compare kinects and cinematic variables of UDK between groups of swimmers with different performances. Twenty-four competitive male swimmers have done four maximal performances of 17 meters of UDK. It was used three underwater cameras putted on 5, 10 and 15 meters of the path. The swimmers were recorded to cinematic analyze. The frames of all performances were digitalized in the program Ariel Perfomance Analysis Systems APAS. It was evaluated the kinematics variables of the swimmer during the UDK using the software Aquanex (Swimming Technology Research, FLO, USA). The mean of the performances between the groups was compared using the T student s test, for the normalized distribution samples and the Mann-Whitneys s U test for the non-normal with confidence value of 95% (p<0,05). It was used the multiple regression analysis to correlate the variables the exerts more influence during the UDK. The results have shown that the difference between both groups could be explained for the following variables: frequency of kicking, peak of force, mean of force, duration of kicking cycle, horizontal maximum speed, maximum down speed, maximum vertical speed down-guided and up-guided normalized by the high of lower limbs. The multiple regression analysis showed that the variables: mean of force and frequency of kicking explain, together, 48% of the performance of time in 5-15 meters. / Entender os fatores que afetam a capacidade de nadar rápido é fundamental para obter êxito no esporte. O movimento de pernas na ondulação subaquática MPOS, possui um ótimo equilíbrio entre minimizar o arrasto e maximizar o impulso, reduzindo o esforço físico exigido do nadador. Conhecer elementos intrínsecos da sua execução, como a frequência, a força, os ângulos e as amplitudes das pernadas levam a compreensão do MPOS que é um dos fatores que mais influência no tempo de nado. O objetivo do estudo, portanto, foi comparar variáveis cinéticas e cinemáticas do MPOS, entre grupos com diferentes desempenhos e correlacionar estas variáveis com o desempenho. Vinte e quatro nadadores competitivos do sexo masculino realizaram quatro execuções máximas de 17 metros do MPOS. Foram utilizadas três câmeras subaquáticas posicionadas nos 5, 10 e 15 m e uma que acompanhava os nadadores durante o percurso. Eles foram filmados para análise cinemática. Os quadros de todas as execuções foram digitalizados manualmente no programa Ariel Perfomance Analysis Systems APAS. Também foram avaliadas as variáveis cinéticas aplicadas pelo nadador durante o MPOS por meio do sistema de aquisição de dados Aquanex (Swimming Technology Research, FLO, USA). A média das execuções entre os grupos foi comparada através do teste t de Student, para as variáveis que apresentaram distribuição normal e o teste "U" de Mann-Whitney com nível de confiança de 95% (p<0,05). Foi utilizada, ainda, a análise de regressão múltipla para correlacionar as variáveis que mais influenciaram durante o MPOS. Os resultados encontrados demonstraram que a diferença entre os grupos pode ser explicada pelas seguintes variáveis: frequência de pernadas, pico de força, força média, duração do ciclo, velocidade máxima horizontal, velocidade máxima vertical para baixo, velocidade máxima vertical para baixo e para cima normalizada pela altura dos membros inferiores. Com base na análise de regressão múltipla, as variáveis força média e frequência da pernada explicaram, em conjunto, 48% do desempenho no tempo de 5-15 m.