No description available.

PURPOSE The purpose of this study was to determine if performing static active knee extension hamstring stretching using the Pneumex Pro-Vibe vibrating platform increased acute hamstring range of motion (ROM) greater than traditional static active knee extension hamstring stretching. METHODS: A within subject design was utilized with subjects undergoing static stretching with vibration and without vibration (conditions counterbalanced). Pre- and post-test active and passive ROM was measured for the right leg, with subjects first undergoing a 5-minute warm-up on a stationary bicycle. Supine active knee extension was performed on the Pro-Vibe platform with and without vibration. The stretch was held 3 times each for 30 seconds, with a 20-second rest period between each stretch. Vibration was set at 30 Hz at the “high” amplitude setting. Active hamstring ROM was measured via active knee extension using a goniometer with the leg in 90° of hip flexion. Passive ROM was measured via clinician-assisted knee extension with the leg in 90° of hip flexion. RESULTS: A 2-way repeated measures ANOVA was performed for passive ROM, and revealed a significant main effect for condition, F (1, 23) = 0.5875, p < 0.05, and time, F (1, 23) = 5.029, p < 0.05. Another repeated measures ANOVA was performed for active ROM with the same factors, and revealed a significant time by condition interaction, F (1, 23) = 4.730, p < 0.05, and a significant main effect for time, F (1, 23) = 18.612, p < 0.001. Post-hoc paired samples t-tests determined the difference between the pre-test and post-test measurements for each condition. Active ROM showed a significant difference pre-test to post-test for the vibration condition, t (23) = -5.41, p < 0.001. The vibration condition also resulted in significantly different pre-test vs. post-test measurements on passive ROM, t (23) = -2.55, p < 0.05. In both cases the average ROM was higher for the post-test. DISCUSSION: Three 30-second active knee extension hamstring stretches using a vibrating platform are sufficient to cause significant acute increases in hamstring ROM. These findings suggest this device may be useful when desiring increased hamstring ROM.

Introdução: O alongamento destaca-se como recurso empregado pelos fisioterapeutas no tratamento e prevenção de doenças musculoesqueléticas. Porém, a diversidade de técnicas, frequência, duração de sustentação do alongamento geram dúvidas do que é realmente necessário para se obter melhores resultados com o alongamento. Objetivo: Comparar dois tempos distintos de duração de alongamento em um programa de seis semanas de treinamento de alongamento estático passivo, 30s e 60s, sobre a flexibilidade e a força dos músculos isquiotibiais e força de quadríceps de mulheres jovens. Material e Métodos: Esta pesquisa se caracteriza por um estudo clínico randomizado de acompanhamento longitudinal. A amostra foi composta por 45 mulheres com idades entre 20 e 40 anos, divididas em três grupos (G30) programa de treinamento de alongamento estático passivo com 30 segundos de duração; (G60) programa de treinamento de alongamento estático passivo com 60 segundos de duração e (GC) grupo controle, sem intervenção. As coletas foram realizadas em três etapas, que consistiu em (1) pré-teste para avaliar a flexibilidade e força muscular de quadril e joelho, (2) a intervenção, onde foram executados alongamentos com diferentes tempos de execução, 30 e 60 segundos, realizados duas vezes por semana durante 6 semanas e (3) pós teste que consistiu na reavaliação da flexibilidade e força, após período de intervenção. Para obtenção dos valores de amplitude de movimento do quadril e do joelho foi utilizado um goniômetro universal e para a coleta de dados relativa à força muscular, o dinamômetro isocinético Cybex Norm. A análise estatística consistiu na aplicação do teste de Shapiro Wilk e Levene para ver a normalidade e homogeneidade dos dados, respectivamente. Para a comparação entre os grupos (G30, G60 e GC) e intragrupos em momentos distintos (pré e pós) foi utilizado uma ANOVA two way de medidas repetidas. Para avaliar as diferenças identificadas o post-hoc de Bonferroni foi utilizado. A análise foi feita no software SPSS 20.0 e o nível de significância adotado foi de 0,05. Resultados: Os resultados do presente estudo mostram um aumento significativo no pico de torque concêntrico de extensores do joelho do momento pré para o pós nos grupos de 30 segundos (G30) e 60 segundos (G60) e uma diminuição significativa para o controle (GC). O pico de torque excêntrico dos extensores do joelho também apresentou um aumento significativo do momento pré para o pós em todos os grupos. Porém não apresentou diferença significativa nos picos de torque concêntrico e excêntrico de flexores do joelho. Em relação à amplitude de movimento de quadril e joelho, não houve diferença significativa entre os grupos nem intragrupos nos diferentes momentos. Conclusão: Os resultados mostraram que um único alongamento, de 30s ou 60s, executado duas vezes por semana num período de treinamento de seis semanas é insuficiente para promover aumento na amplitude de movimento de quadril e joelho e de ganho de força do grupo muscular alongado (isquiotibiais). No entanto, parece influenciar no aumento da força do grupo muscular oposto ao alongado (quadríceps). / Introduction: Stretching is a resource widely used by physiotherapists to treat and prevent musculoskeletal disorders. However, discrepancies in stretching techniques, training period, and duration of stretching make it complicated to ensure what stretching parameters lead to the most satisfactory results. Objective: to compare the effect of two distinct durations of stretching (30s and 60s) on hamstrings flexibility and strength of untrained young women during a six-weeks training program. Material e Methodos: This research is characterized as a randomized clinical longitudinal study. Forty-five women (20 to 40 years old) participated in this study, they were divided in three groups: passive static stretching held for 30 seconds (G30); passive static stretching held for 60 seconds (G60); and control group, no intervention (CG). Data collection was carried out in three phases: (1) pre-test of hamstrings’ flexibility and strength; (2) Intervention, in which either 30s or 60s of passive static stretching was performed twice a week for six weeks; (3) post-test of hamstrings’ flexibility and strength. Hip and knee range of motion was measured using a universal goniometer, whereas the information about knee force production was gathered using an Isokinetic Dynamometer. Regarding statistical analyses, Shapiro WilK and Levene tests were used to data normalization and homogenization, respectively. For inter-groups (G30, G60, and CG), and intra-groups (pre and post) comparisons a mixed ANOVA two way was performed. If significant interaction was observed, a Bonferroni post hoc test was conducted. All data were analyzed using SPSS 20, and statistical significance was set as p ≤ 0.05.Results: The results of the present study show significant increase of knee extensors Eccentric and Concentric Peak Torque in both G30 and G60 after stretching training, CG showed significant decrease on knee extensor Concentric Peak Torque, and increase on knee extensor Eccentric Peak Torque after stretching training. Nevertheless, knee flexors Concentric and Eccentric Peak Torque remained unaltered in all groups after stretching training. In relation to range of hip and knee movement, there was no significant difference between the groups or intra groups or the times. Conclusion: The findings showed that a single stretch , 30 or 60 s, of static stretching performed twice a week for six weeks are not sufficient to improve flexibility or strength of the stretched muscles. However, this parameter has an effect muscle strength of the antagonist group.

Introdução: O alongamento destaca-se como recurso empregado pelos fisioterapeutas no tratamento e prevenção de doenças musculoesqueléticas. Porém, a diversidade de técnicas, frequência, duração de sustentação do alongamento geram dúvidas do que é realmente necessário para se obter melhores resultados com o alongamento. Objetivo: Comparar dois tempos distintos de duração de alongamento em um programa de seis semanas de treinamento de alongamento estático passivo, 30s e 60s, sobre a flexibilidade e a força dos músculos isquiotibiais e força de quadríceps de mulheres jovens. Material e Métodos: Esta pesquisa se caracteriza por um estudo clínico randomizado de acompanhamento longitudinal. A amostra foi composta por 45 mulheres com idades entre 20 e 40 anos, divididas em três grupos (G30) programa de treinamento de alongamento estático passivo com 30 segundos de duração; (G60) programa de treinamento de alongamento estático passivo com 60 segundos de duração e (GC) grupo controle, sem intervenção. As coletas foram realizadas em três etapas, que consistiu em (1) pré-teste para avaliar a flexibilidade e força muscular de quadril e joelho, (2) a intervenção, onde foram executados alongamentos com diferentes tempos de execução, 30 e 60 segundos, realizados duas vezes por semana durante 6 semanas e (3) pós teste que consistiu na reavaliação da flexibilidade e força, após período de intervenção. Para obtenção dos valores de amplitude de movimento do quadril e do joelho foi utilizado um goniômetro universal e para a coleta de dados relativa à força muscular, o dinamômetro isocinético Cybex Norm. A análise estatística consistiu na aplicação do teste de Shapiro Wilk e Levene para ver a normalidade e homogeneidade dos dados, respectivamente. Para a comparação entre os grupos (G30, G60 e GC) e intragrupos em momentos distintos (pré e pós) foi utilizado uma ANOVA two way de medidas repetidas. Para avaliar as diferenças identificadas o post-hoc de Bonferroni foi utilizado. A análise foi feita no software SPSS 20.0 e o nível de significância adotado foi de 0,05. Resultados: Os resultados do presente estudo mostram um aumento significativo no pico de torque concêntrico de extensores do joelho do momento pré para o pós nos grupos de 30 segundos (G30) e 60 segundos (G60) e uma diminuição significativa para o controle (GC). O pico de torque excêntrico dos extensores do joelho também apresentou um aumento significativo do momento pré para o pós em todos os grupos. Porém não apresentou diferença significativa nos picos de torque concêntrico e excêntrico de flexores do joelho. Em relação à amplitude de movimento de quadril e joelho, não houve diferença significativa entre os grupos nem intragrupos nos diferentes momentos. Conclusão: Os resultados mostraram que um único alongamento, de 30s ou 60s, executado duas vezes por semana num período de treinamento de seis semanas é insuficiente para promover aumento na amplitude de movimento de quadril e joelho e de ganho de força do grupo muscular alongado (isquiotibiais). No entanto, parece influenciar no aumento da força do grupo muscular oposto ao alongado (quadríceps). / Introduction: Stretching is a resource widely used by physiotherapists to treat and prevent musculoskeletal disorders. However, discrepancies in stretching techniques, training period, and duration of stretching make it complicated to ensure what stretching parameters lead to the most satisfactory results. Objective: to compare the effect of two distinct durations of stretching (30s and 60s) on hamstrings flexibility and strength of untrained young women during a six-weeks training program. Material e Methodos: This research is characterized as a randomized clinical longitudinal study. Forty-five women (20 to 40 years old) participated in this study, they were divided in three groups: passive static stretching held for 30 seconds (G30); passive static stretching held for 60 seconds (G60); and control group, no intervention (CG). Data collection was carried out in three phases: (1) pre-test of hamstrings’ flexibility and strength; (2) Intervention, in which either 30s or 60s of passive static stretching was performed twice a week for six weeks; (3) post-test of hamstrings’ flexibility and strength. Hip and knee range of motion was measured using a universal goniometer, whereas the information about knee force production was gathered using an Isokinetic Dynamometer. Regarding statistical analyses, Shapiro WilK and Levene tests were used to data normalization and homogenization, respectively. For inter-groups (G30, G60, and CG), and intra-groups (pre and post) comparisons a mixed ANOVA two way was performed. If significant interaction was observed, a Bonferroni post hoc test was conducted. All data were analyzed using SPSS 20, and statistical significance was set as p ≤ 0.05.Results: The results of the present study show significant increase of knee extensors Eccentric and Concentric Peak Torque in both G30 and G60 after stretching training, CG showed significant decrease on knee extensor Concentric Peak Torque, and increase on knee extensor Eccentric Peak Torque after stretching training. Nevertheless, knee flexors Concentric and Eccentric Peak Torque remained unaltered in all groups after stretching training. In relation to range of hip and knee movement, there was no significant difference between the groups or intra groups or the times. Conclusion: The findings showed that a single stretch , 30 or 60 s, of static stretching performed twice a week for six weeks are not sufficient to improve flexibility or strength of the stretched muscles. However, this parameter has an effect muscle strength of the antagonist group.

Introdução: O alongamento destaca-se como recurso empregado pelos fisioterapeutas no tratamento e prevenção de doenças musculoesqueléticas. Porém, a diversidade de técnicas, frequência, duração de sustentação do alongamento geram dúvidas do que é realmente necessário para se obter melhores resultados com o alongamento. Objetivo: Comparar dois tempos distintos de duração de alongamento em um programa de seis semanas de treinamento de alongamento estático passivo, 30s e 60s, sobre a flexibilidade e a força dos músculos isquiotibiais e força de quadríceps de mulheres jovens. Material e Métodos: Esta pesquisa se caracteriza por um estudo clínico randomizado de acompanhamento longitudinal. A amostra foi composta por 45 mulheres com idades entre 20 e 40 anos, divididas em três grupos (G30) programa de treinamento de alongamento estático passivo com 30 segundos de duração; (G60) programa de treinamento de alongamento estático passivo com 60 segundos de duração e (GC) grupo controle, sem intervenção. As coletas foram realizadas em três etapas, que consistiu em (1) pré-teste para avaliar a flexibilidade e força muscular de quadril e joelho, (2) a intervenção, onde foram executados alongamentos com diferentes tempos de execução, 30 e 60 segundos, realizados duas vezes por semana durante 6 semanas e (3) pós teste que consistiu na reavaliação da flexibilidade e força, após período de intervenção. Para obtenção dos valores de amplitude de movimento do quadril e do joelho foi utilizado um goniômetro universal e para a coleta de dados relativa à força muscular, o dinamômetro isocinético Cybex Norm. A análise estatística consistiu na aplicação do teste de Shapiro Wilk e Levene para ver a normalidade e homogeneidade dos dados, respectivamente. Para a comparação entre os grupos (G30, G60 e GC) e intragrupos em momentos distintos (pré e pós) foi utilizado uma ANOVA two way de medidas repetidas. Para avaliar as diferenças identificadas o post-hoc de Bonferroni foi utilizado. A análise foi feita no software SPSS 20.0 e o nível de significância adotado foi de 0,05. Resultados: Os resultados do presente estudo mostram um aumento significativo no pico de torque concêntrico de extensores do joelho do momento pré para o pós nos grupos de 30 segundos (G30) e 60 segundos (G60) e uma diminuição significativa para o controle (GC). O pico de torque excêntrico dos extensores do joelho também apresentou um aumento significativo do momento pré para o pós em todos os grupos. Porém não apresentou diferença significativa nos picos de torque concêntrico e excêntrico de flexores do joelho. Em relação à amplitude de movimento de quadril e joelho, não houve diferença significativa entre os grupos nem intragrupos nos diferentes momentos. Conclusão: Os resultados mostraram que um único alongamento, de 30s ou 60s, executado duas vezes por semana num período de treinamento de seis semanas é insuficiente para promover aumento na amplitude de movimento de quadril e joelho e de ganho de força do grupo muscular alongado (isquiotibiais). No entanto, parece influenciar no aumento da força do grupo muscular oposto ao alongado (quadríceps). / Introduction: Stretching is a resource widely used by physiotherapists to treat and prevent musculoskeletal disorders. However, discrepancies in stretching techniques, training period, and duration of stretching make it complicated to ensure what stretching parameters lead to the most satisfactory results. Objective: to compare the effect of two distinct durations of stretching (30s and 60s) on hamstrings flexibility and strength of untrained young women during a six-weeks training program. Material e Methodos: This research is characterized as a randomized clinical longitudinal study. Forty-five women (20 to 40 years old) participated in this study, they were divided in three groups: passive static stretching held for 30 seconds (G30); passive static stretching held for 60 seconds (G60); and control group, no intervention (CG). Data collection was carried out in three phases: (1) pre-test of hamstrings’ flexibility and strength; (2) Intervention, in which either 30s or 60s of passive static stretching was performed twice a week for six weeks; (3) post-test of hamstrings’ flexibility and strength. Hip and knee range of motion was measured using a universal goniometer, whereas the information about knee force production was gathered using an Isokinetic Dynamometer. Regarding statistical analyses, Shapiro WilK and Levene tests were used to data normalization and homogenization, respectively. For inter-groups (G30, G60, and CG), and intra-groups (pre and post) comparisons a mixed ANOVA two way was performed. If significant interaction was observed, a Bonferroni post hoc test was conducted. All data were analyzed using SPSS 20, and statistical significance was set as p ≤ 0.05.Results: The results of the present study show significant increase of knee extensors Eccentric and Concentric Peak Torque in both G30 and G60 after stretching training, CG showed significant decrease on knee extensor Concentric Peak Torque, and increase on knee extensor Eccentric Peak Torque after stretching training. Nevertheless, knee flexors Concentric and Eccentric Peak Torque remained unaltered in all groups after stretching training. In relation to range of hip and knee movement, there was no significant difference between the groups or intra groups or the times. Conclusion: The findings showed that a single stretch , 30 or 60 s, of static stretching performed twice a week for six weeks are not sufficient to improve flexibility or strength of the stretched muscles. However, this parameter has an effect muscle strength of the antagonist group.

Les étirements sont aujourd'hui une pratique courante dans les milieux sportifs et de réadaptation. Ils sont habituellement recommandés dans le but de contribuer à la prévention des blessures (Willson et al. 1991 ;Pope et al. 2000), à l’amélioration de la performance sportive lorsque celle-ci nécessite une amplitude articulaire importante (Heyters, 1985 ;Hortobagyi et al. 1985) et à la récupération de la mobilité articulaire dans le cadre d’un programme de réadaptation (Magnusson et al. 1996b). Ces méthodes, qui se sont développées ces dernières années, font classiquement appel à l’étirement passif et aux étirements neurofacilités (PNF), présentés initialement par Kabat (1958). Plus récemment, un intérêt particulier a été porté au travail musculaire excentrique. Des études ont montré que celui-ci permettait également d’augmenter l’amplitude articulaire (Willson et al. 1991 ;Nelson et Bandy, 2004). <p><p>Dans une première partie de ce travail, il nous a semblé intéressant de comparer les effets de l’étirement passif à ceux des étirements PNF par "contracté-relâché" et "contracté de l’antagoniste". Si les modalités d'application de chaque étirement sont différentes, elles présentent un intérêt majeur. De fait, elles permettent de faire varier les conditions d'allongement des différentes structures du système myotendineux, en modulant l'activité volontaire des musculatures agoniste ou antagoniste. En effet, si l’étirement passif s'effectue sans activation volontaire, l’étirement par "contracté-relâché" consiste à faire précéder l'étirement passif, d'une contraction volontaire maximale isométrique de la musculature agoniste. L’étirement par "contracté de l’antagoniste" associe à l'allongement de la musculature agoniste, une contraction volontaire maximale de la musculature antagoniste. Si de nombreuses études s'intéressent encore actuellement à caractériser leurs effets respectifs, elles ont déjà permis de montrer que ceux-ci avaient au moins deux origines distinctes, l'une neurophysiologique et l'autre mécanique (Taylor et al. 1990 ;Hutton, 1993). Au plan neurophysiologique, il est bien accepté que ces méthodes induisent une modulation de l'activité réflexe tonique facilitant le relâchement musculaire et par conséquent l’amplitude articulaire (Guissard et al. 1988 ;2001). Il est également bien admis que l’importance de ces effets sur la musculature est variable selon la méthode employée (Guissard et Duchateau, 2006). Au plan mécanique, des études menées chez l’animal ont montré que l’étirement passif modifie les caractéristiques viscoélastiques des tissus (Taylor et al. 1990), et de fait favorise l’allongement des tissus myotendineux (McHugh et al. 1992). Chez le sujet humain, plusieurs expérimentations ont montré que l’étirement par "contracté-relâché" permet d’obtenir un allongement myotendineux et un gain d’amplitude articulaire plus important que par étirement passif (Moore et Hutton, 1980). D’autres études ont montré que l’étirement par "contracté de l’antagoniste" permet de majorer encore les gains obtenus par l’étirement "contracté-relâché" (Osternig et al. 1990). Une première question posée dans ce travail est de savoir si la contribution des processus neurophysiologiques et mécaniques se traduit d’une manière spécifique sur le rapport de compliance des tissus de l’unité myotendineuse. Le développement de techniques d’investigation, telles que l’échographie, permet désormais d’observer le comportement de l’unité myotendineuse, d’une manière non invasive (Fukunaga et al. 1992 ;Herbert et Gandevia, 1995 ;Kuno et Fukunaga, 1995 ;Maganaris et al. 1998). Elle permet ainsi d’étudier les effets d’un étirement ou d’une contraction (Fukunaga et al. 1996) sur le rapport de compliance des structures musculaires et des tissus tendineux. <p> <p>S’il était intéressant d’étudier la spécificité de ces trois méthodes d’étirement classiques par rapport à leurs effets sur les tissus myotendineux, il nous paraissait pertinent d’observer celle d’un travail musculaire excentrique. En effet, la particularité de celui-ci est de soumettre l’unité myotendineuse préalablement activée, à un allongement. En réadaptation, le travail excentrique est généralement proposé dans le but d’améliorer plus rapidement la symptomatologie d’une tendinopathie (Stanish et al. 1986 ;Alfredson et al. 1998). Des études récentes ont indiqué qu’il peut également être proposé pour augmenter l'amplitude articulaire (Nelson et Bandy, 2004). Toutefois, ses effets sur les tissus myotendineux ne sont pas clairement définis dans la littérature. Chez l’animal, Heinemeier et al. (2007) ont comparé les effets d’un entraînement en contractions concentriques et excentriques sur les tissus de l’unité myotendineuse. Leurs résultats indiquent que si les tissus tendineux sont sensibles aux deux modes de contraction pour leurs effets favorisant la synthèse de collagène, les structures musculaires sont spécifiquement sensibles au mode excentrique. Chez le sujet humain, Crameri et al. (2004) ont observé une série de contractions excentriques d’intensité maximale augmente la synthèse de collagène au sein de l’ensemble des tissus de l’unité myotendineuse. Ces résultats montrent que les effets de ce travail ne se limitent pas aux tissus tendineux, tels que certains protocoles thérapeutiques le suggéraient, et que le tissu musculaire doit désormais être associé à la discussion des effets de ce travail musculaire. Dans ce contexte, la deuxième question que nous avons posée est de savoir si l’étirement de l’unité myotendineuse préalablement activée, telle que se caractérise une contraction excentrique, modifie le rapport de compliance des tissus myotendineux par rapport aux méthodes classiques. Autrement dit, si l’étirement de l’unité myotendineuse activée favorise spécifiquement l’allongement de l’un des tissus de l’unité myotendineuse. <p><p>Dans une troisième partie, il nous a paru intéressant d'étudier le comportement à l’étirement de l’unité myotendineuse, dont la compliance était modifiée suite à une désadaptation à long terme. L’hypertonie spastique, qui caractérise une majorité de sujets parétiques spastiques, est généralement caractérisée par une augmentation anormale des résistances opposées à l'étirement passif (Carey et Burghart, 1993). L’origine de ces résistances peut être attribuée à des adaptations tant neurophysiologiques (Pierrot-Deseilligny et Mazières, 1985) que mécaniques et structurelles des tissus de l'unité myotendineuse (Berger et al. 1984 ;Tardieu et al. 1989). Il n’existe pourtant pas encore dans la littérature de consensus les définissant clairement (Fridén et Lieber, 2003). En outre, l’étude récente de Lieber et Fridén (2002) a mis en évidence des modifications de l’architecture des muscles fléchisseurs du carpe. Contrairement à ce qui est généralement proposé au sujet de la longueur des fascicules spastiques (Tardieu et al. 1982), Lieber et Fridén (2002) n’ont pas mis en évidence de raccourcissement de ces derniers. Ainsi, l’hypothèse de Tardieu et al. (1982), selon laquelle le raccourcissement des fascicules est à l’origine de l’augmentation des résistances à l’allongement, ne peut plus être soutenue. Il nous paraissait ainsi intéressant d’associer, à l’observation du comportement des fascicules, celui des tissus tendineux, dans le but de déterminer si l’une de ces deux structures présente des caractéristiques particulières, susceptibles d’expliquer le développement plus important de ces résistances à l’allongement. La troisième question que nous avons posée dans ce travail est de savoir comment se caractérise, à l’étirement, le rapport de compliance des tissus musculaire et tendineux dans un contexte de spasticité. <p><p>Outre le fait que la réponse à ces différentes questions soit fondamentale pour mieux comprendre et spécifier la pratique des méthodes d’étirement, l’objectif de notre travail est non seulement de mettre en évidence le tissu dont l’allongement est spécifiquement favorisé par l’une ou l’autre méthode, mais également de contribuer à différencier celui qui limite l’étirement global du système myotendineux. Dans ce contexte, il sera intéressant de pouvoir recommander la pratique d’une méthode particulière, en fonction des besoins spécifiques de chacun. <p> / Doctorat en Sciences de la motricité / info:eu-repo/semantics/nonPublished

6 ABSTRACT Tittle: Effect of Static and Dynamic Stretching on the Performance of Cadet Category in Competitive Aerobics Objectives: The aim of the work is to find out the type, method and use of static and dynamic stretching in the training of cadet girls in the training of sports aerobics through the opinions of competitive aerobics coaches. The theoretical part consists of research on the issue. In the practical part, a questionnaire survey and an interview are used, conducted in person by the author of the diploma thesis or sent by e-mail, or conducted by telephone or otherwise online. The outputs from this questionnaire + interview are analyzed, compared and evaluated with specific clear outputs. Methods: The work consists of a theoretical and a practical part, while the theoretical part is conceived descriptively. The research part uses the method of qualitative research - a questionnaire. Competitive aerobics coaches are interviewed through a questionnaire and in the form of a guided interview. The interview is conducted in person, according to the prepared questions, and the answers are then logically sorted, evaluated and commented. Descriptive statistics are used for the actual classification and analysis of the obtained data. Results: The results of the work showed the type, method and use of...

Background: Foam rolling (FR) is a promising new trend in the world of resistance training, sports and  athletics. It is often used as a warm up activity as a substitute or addition to  stretching modalities such as static stretching (SS). The proposed benefits behind FR is that it can lead to  both acute and chronic increases in performance and flexibility. Aim: The aim of this study was to investigate the effects of two different warm­up intervention protocols  of the hamstrings musculature on: 1) Performance in the bilateral standing long jump 2) Flexibility in a  supine active­knee­extension test. Method: The study consisted of sixteen male participants who were all healthy adult recreational athletes.  The two different interventions were, a) Static Stretching protocol (SS) and b) a Foam Rolling protocol  (FR). These were compared to a baseline warm up (BLWU). The SS consisted of 1 x 30 seconds of active  SS using the lying supine active­knee­extension position after a short warm­up. The FR consisted of 1  bout of 30 seconds of FR of the hamstrings musculature of each leg after a short warm­up. BLWU  consisted of a short warm­up (5 submaximal bilateral standing long jumps). Performance was measured  using a bilateral standing long jump test. Flexibility was measured with a goniometer using a lying supine active ­knee­ extension test. The student’s t­test was used to study differences between and within groups (BLWU, SS, FR). Results: No differences between BLWU and Post­SS (p=0.89) as well as BLWU compared to Post­FR (p=0.86) was detected for performance. However, an increase in flexibility was shown favoring Post­SS over BLWU (p=0.021) as well as Post­FR over BLWU (p=0.045). No significant difference was seen  between changes in the Post­SS and Post­FR groups in either performance or flexibility (p=0.887 and  p=0.944 respectively). Conclusion: It seems that both SS and FR are similarly viable and effective methods for acute increases  in flexibility in the active­knee­extension test without subsequent decreases in performance of the bilateral standing long jump.

Dans un contexte de performance sportive, de réhabilitation ou de santé, les étirements sont couramment utilisés dans le but de préparer le système neuromusculaire à l’exercice subséquent. Si la littérature montre majoritairement que les étirements altèrent de façon aigue la performance musculaire et/ou fonctionnelle, il existe toutefois des études dont les résultats diffèrent, suggérant l’influence d’un certain nombre de facteurs sur la variabilité des réponses du système neuromusculaire. Pour une meilleure compréhension de cette variabilité et des mécanismes impliqués, cette thèse avait pour objectif d’examiner l’influence de différents paramètres sur le système neuromusculaire : la durée d’étirement, le groupe musculaire et la modalité d’étirement. Au travers de quatre études, il a été montré que les étirements statiques pouvaient altérer la production de force maximale et les propriétés neuromusculaires indépendamment de la durée d’étirement. Cependant, il est apparu que ces modulations étaient spécifiques au muscle, et plus précisément à la raideur relative du système musculo-tendineux. Indépendamment de la durée d’étirement, les étirements statiques ne seraient pas efficaces pour préparer le système neuromusculaire à une activité musculaire subséquente, et notamment pour des muscles raides. Plus particulièrement, les étirements dynamiques ne paraissent pas plus efficaces. Même si les effets néfastes ont été diminués comparativement aux étirements statiques, ils ne favoriseraient pas davantage la production de force ni la commande nerveuse. Toutefois, il est intéressant de noter qu’une durée courte d’étirements dynamiques peut réduire la résistance passive à l’étirement, et donc augmenter potentiellement l’amplitude articulaire maximale, sans affecter les capacités de production de force. Finalement, les étirements dynamiques pourraient être envisagés comme une activité musculaire dynamique, qui compense partiellement les effets néfastes de l’étirement sur la performance musculaire. D’un point de vue pratique, ceci suggère que ce type d’étirements peut être réalisé avant une performance, mais néanmoins accompagnés d’une activité musculaire de plus haute intensité, afin d’optimiser les effets de l’échauffement musculaire sur le système neuromusculaire. En définitive, la variabilité des réponses du système neuromusculaire serait dépendante de facteurs spécifiques, tels que la modalité d’étirement et la raideur relative du système musculo-tendineux, soulignant l’importance de les prendre en considération dans la pratique. / Stretching is traditionally incorporated into pre-exercise routines in health, rehabilitation and sporting environments to condition the neuromuscular system for exercise. While a large body of evidence reported that stretching may acutely impair the subsequent muscular performance, some conflicting results highlight possible mitigating factors of neuromuscular responses variability. Because the limited data available do not present a clear consensus, the aim of this thesis was to investigate the effects of different factors on neuromuscular responses to stretch: the muscle group, the stretch duration and modality. By means of four studies, it has been shown that static stretching may alter maximal voluntary torque and neuromuscular properties, irrespective of the stretch duration. However, these modulations were dependent on the muscle group, and more specifically on the intrinsic stiffness of the muscle-tendon system. Regardless of the stretch duration, static stretching appears to be not effective, or even detrimental, to prepare the musculotendinous system for subsequent exercises, and especially for stiff muscles. It is also relevant that dynamic stretching was not better than static stretching. Even if stretch-induced impairments were mitigated compared to static stretching, dynamic stretching would not optimize muscle strength capacities and central nervous system. However, a short duration of dynamic stretching may be sufficient to reduce passive resistive torque, and therefore potentially increase maximal range of motion, without affecting muscle strength capacities. Finally, dynamic stretching could be considered as dynamic muscle activity, which would partly counteract deleterious muscle-tendon stretching effects. From a practical point of view, dynamic stretching could be a part of warm-up procedure, but should be associated to stronger contractions to optimize the improvement in muscle strength capacities. In summary, the variability of neuromuscular responses to stretch would be dependent on specific factors, such as stretching modality and relative stiffness of the musculotendinous system, emphasizing the importance of taking it into consideration in practice.

This thesis deals with the method for time conversion of an audio signal based on a different approach to groups tonal and non-tonal segment signal implemented in Matlab. The first part deal with methods for musical signal processing based on time compression or expansion and describes the problems associated with the current way of implementing these methods. The following describes the methods of variable segmentation and tonal and non-tonal components detection in the audio recording. At the second part are these methods of variable segmentation, tonal component detection and time compression or expansion implemented in MATLAB. At the third part is performed testing on sound recordings and evaluation of results.