Made available in DSpace on 2016-06-02T19:22:55Z (GMT). No. of bitstreams: 1 4273.pdf: 640166 bytes, checksum: 0c9fc1f3e1c6ddb8472d73914461506a (MD5) Previous issue date: 2012-03-30 / Universidade Federal de Sao Carlos / Although tissue cooling is widely used in the treatment of musculoskeletal disorders there is still controversy about its effects on muscular performance. It is important to study this issue since cooling is also combined with exercise. Objective. To compare the effects of ice pack and cold water immersion on the muscular performance parameters of plantar flexors and electromyography (EMG) activity of the triceps surae. Design. Subjects were randomly assigned treatment with either ice pack (n=20) or cold water immersion (n=21). Independent variables were cold modality (ice pack or cold water immersion), muscle action (isometric and concentric isokinetic, angular velocity of isokinetic test (60 and 120°/s) and measurement time (pre- and post-cooling). Dependent variables were skin temperature, muscular performance and EMG activity. Methods. The sample included 41 healthy men with a mean age of 22.15 (SD=2.89). In each group one of the two cold modalities was applied to the calf region for 20 minutes. Skin temperature, plantar flexors muscular performance parameters and EMG activity of the triceps surae were measured before and after cooling. Results. Ice pack increased isometric peak torque. Both cold modalities reduced EMG activity in both muscles during isometric contraction. Both cold modalities reduced peak torque and total work during isokinetic contraction at both velocities. Ice pack was more effective at reducing EMG activity in isokinetic contractions. Limitations. The examiner was not blinded regarding treatment group and the population included only young healthy participants. Conclusions. Ice pack and cold water immersion showed similar effects on muscular performance, which depends on the muscle action performed. Cooling decreased isokinetic performance and the ice pack increased isometric torque. The results suggest that caution is required when performing activities after cooling, especially tasks involving maximal isokinetic contractions. / Embora o resfriamento tecidual seja amplamente utilizado no tratamento de lesões músculo esqueléticas há ainda controvérsias sobre seus efeitos no desempenho muscular. Estudar esse aspecto é importante uma vez que o resfriamento também é utilizado associado a exercícios físicos. Objetivo: Comparar os efeitos do pacote de gelo e da imersão em água gelada sobre parâmetros do desempenho muscular dos flexores plantares e atividade eletromiográfica (EMG) do tríceps sural. Desenho: Foi realizado um estudo experimental com distribuição aleatória dos participantes em dois grupos de intervenção, pacote de gelo (n=20) e imersão em água gelada (n=21). As variáveis independentes foram grupo experimental (pacote de gelo ou imersão em água gelada), tipo de contração (isométrica ou isocinética concêntrica), velocidade angular do teste isocinético (60 e 120°/s) e tempo de mensuração (pré- e pós-resfriamento). Variáveis dependentes foram temperatura da pele, parâmetros de desempenho muscular e atividade EMG. Métodos: Quarenta e um homens saudáveis, com média de idade (DP) de 22,15 (2,89) anos participaram do estudo. Cada grupo recebeu uma das duas modalidades de resfriamento, aplicada sobre a região da panturrilha por 20 minutos. A temperatura da pele e parâmetros do desempenho muscular dos flexores plantares e da atividade EMG dos músculos sóleo e gastrocnêmio medial e lateral foram avaliados antes e imediatamente após o resfriamento. Resultados: O pacote de gelo causou aumento no pico de torque isométrico. A atividade EMG foi reduzida em ambos os músculos sóleo e gastrocnêmio pelas duas modalidades de resfriamento durante a contração isométrica. As duas modalidades de resfriamento reduziram o pico de torque e trabalho total na contração isocinética em ambas as velocidades avaliadas. De modo geral, o pacote de gelo foi mais efetivo para reduzir a atividade EMG na contração isocinética. Conclusões: O pacote de gelo e a imersão em água gelada mostram efeitos similares sobre o desempenho muscular, o qual é dependente a ação muscular realizada. O resfriamento muscular diminui o desempenho durante a contração isocinético e o pacote de gelo aumenta o torque isométrico. Os resultados sugerem cautela quando forem realizadas atividades dinâmicas após o resfriamento, especialmente durante contrações isocinéticas máximas.

Title: The influence of bicycle saddle position on muscle tone of the triceps surae muscle Objectives: The aim of this thesis is to find out what is the effect of changing the bicycle saddle position on muscle tone of triceps surae muscle. And whether the higher seat position will also increase muscle tone of the calf muscle. Methods: The thesis is divided into the theoretical part, where there is the information from the scientific literature on the subject and a practical part. The theoretical part includes anatomical descriptions and rheological properties of skeletal muscles, muscle tension and its regulation. Part of it is also the biomechanics of cycling, bike geometry and the options of bicycle seat setting and also the risk implications of the incorrect bicycle seat position. The practical part was prepared as a research by measuring of muscle tone by the myotonometer. For measurement was used the triceps surae muscle of the seven probands on the dominant lower limb. The measurement were twice two weeks apart with the different bicycle seat height. Results: The measurement results confirmed that change of bicycle saddle position has an influence on the muscle tone and that the higher saddle position will also increase muscle tone of the calf muscle. Keywords: bicycle saddle position, saddle...