A permanência em pé por um determinado período de tempo exige que os indivíduos produzam periodicamente mudanças posturais, que podem favorecer a adoção de posturas mais assimétricas. Diante da deterioração do sistema de controle postural, é possível que idosos tenham uma dificuldade em permanecerem assimétricos em atividades do cotidiano. Em adição, variações no padrão de ativação muscular podem aumentar o gasto energético e levar os idosos a fadiga, o que resulta em sérias consequências como aumento no risco de quedas. Acredita-se que mudanças posturais durante a postura relaxada ocorram distintamente em adultos jovens e idosos, podem exigir esforços musculares variados e assim influenciar no gasto energético. O presente estudo investigou as assimetrias posturais, ativações musculares e gasto energético em adultos jovens e idosos saudáveis na postura ereta. Cinquenta e três jovens e 16 idosos permaneceram em diferentes posturas enquanto registrou-se as assimetrias na distribuição de peso ao longo do tempo (ADPm). Todos os idosos e 12 jovens submeteram-se ao registro eletromiográfico para análise dos padrões de ativação muscular de músculos da coxa e perna, e 7 indivíduos de cada grupo foram submetidos ao registro de gases para análise do gasto energético, consumo de oxigênio (VO2), quociente respiratório (R) e medida de frequência cardíaca. Os idosos apresentaram dificuldade na transferência de peso em posturas mais assimétricas e ambos os grupos apresentaram ligeira assimetria na postura ereta quieta (em torno de 5±4% de ADPm). Na postura relaxada a maior parte do tempo os indivíduos permaneceram em faixas de pequenas assimetrias, seguido de um tempo menor em posturas significativamente assimétricas. Em geral, as ativações musculares foram maiores em idosos, porém eles foram capazes de recrutar músculos de modo similar aos jovens. O aumento da atividade do músculo gastrocnêmio foi proporcional às posturas mais assimétricas em ambos os grupos. O gasto energético não sofreu grandes variações em condições de simetria ou assimetria posturais em jovens e idosos, porém parece que o aumento do gasto energético nos idosos está relacionado com o aumento da atividade muscular, o que poderia justificar a adoção de posturas menos assimétricas por parte desses indivíduos. Os resultados do presente estudo levantam a questão da possibilidade de haver maior gasto energético, principalmente em idosos, e abre novas possibilidades para que futuros estudos possam compreender a demanda metabólica envolvida na manutenção da postura ereta / To remain standing for a certain period of time we periodically produce postural changes, which may favouring the adoption of more asymmetric postures. In face of the postural control system deterioration, it is possible that older people find it difficult to adopt more asymmetrical postures during daily life activities. In addition, changes in muscle activation pattern may increase energy cost to stand in asymmetric posture, which would lead to muscle fatigue and as consequence increase in fall risk in this population. Thus, postural changes during relaxed postures and the muscular demand necessary to perform such changes may differ among young and older adults, resulting in different energy cost. The present study investigated body weight asymmetries, muscle activations and energy cost in healthy young and elderly adults during sanding tasks with different constrains. Fifty-three young and sixteen elderly subjects remained at different positions while we recorded the body weight asymmetry over time (ADPm). All the elderly participants and twelve young adults undergone to electromyographic record of the thigh and leg muscles, and 7 subjects in each group to gas record in order to quantify the energy cost, oxygen consumption (VO2) and respiratory quotient (R) and registered heart rate. During quiet standing task, both age groups showed a slight and similar WDA (mean values around 5%). However, the elderly had difficulty in maintaining more asymmetric postures - they were less asymmetrical than young in tasks that required great WDA. In the relaxed position, most of the time the subjects remained in small asymmetry ranges, followed by a shorter period in more asymmetric postures. In general, muscle activation level was higher in the elderly, but they were able to recruit muscle in a similar way to young subjects. In addition, gastrocnemius activity increased proportionally to body weight support in both age groups - it was greater in the supportive limb in the most asymmetric postures. Although in this study the energy cost was not significantly affected by the asymmetry in body weight distribution in young and old individuals, it seems that the increased energy cost in the elderly is associated with an increase in muscle activity, which might explain the adoption of less asymmetric postures by these individuals. The results of this study raise the question of the possibility of higher energy expenditure in more asymmetric postures, especially in the elderly, and opens new possibilities for future studies to understand the metabolic demands during upright standing

A permanência em pé por um determinado período de tempo exige que os indivíduos produzam periodicamente mudanças posturais, que podem favorecer a adoção de posturas mais assimétricas. Diante da deterioração do sistema de controle postural, é possível que idosos tenham uma dificuldade em permanecerem assimétricos em atividades do cotidiano. Em adição, variações no padrão de ativação muscular podem aumentar o gasto energético e levar os idosos a fadiga, o que resulta em sérias consequências como aumento no risco de quedas. Acredita-se que mudanças posturais durante a postura relaxada ocorram distintamente em adultos jovens e idosos, podem exigir esforços musculares variados e assim influenciar no gasto energético. O presente estudo investigou as assimetrias posturais, ativações musculares e gasto energético em adultos jovens e idosos saudáveis na postura ereta. Cinquenta e três jovens e 16 idosos permaneceram em diferentes posturas enquanto registrou-se as assimetrias na distribuição de peso ao longo do tempo (ADPm). Todos os idosos e 12 jovens submeteram-se ao registro eletromiográfico para análise dos padrões de ativação muscular de músculos da coxa e perna, e 7 indivíduos de cada grupo foram submetidos ao registro de gases para análise do gasto energético, consumo de oxigênio (VO2), quociente respiratório (R) e medida de frequência cardíaca. Os idosos apresentaram dificuldade na transferência de peso em posturas mais assimétricas e ambos os grupos apresentaram ligeira assimetria na postura ereta quieta (em torno de 5±4% de ADPm). Na postura relaxada a maior parte do tempo os indivíduos permaneceram em faixas de pequenas assimetrias, seguido de um tempo menor em posturas significativamente assimétricas. Em geral, as ativações musculares foram maiores em idosos, porém eles foram capazes de recrutar músculos de modo similar aos jovens. O aumento da atividade do músculo gastrocnêmio foi proporcional às posturas mais assimétricas em ambos os grupos. O gasto energético não sofreu grandes variações em condições de simetria ou assimetria posturais em jovens e idosos, porém parece que o aumento do gasto energético nos idosos está relacionado com o aumento da atividade muscular, o que poderia justificar a adoção de posturas menos assimétricas por parte desses indivíduos. Os resultados do presente estudo levantam a questão da possibilidade de haver maior gasto energético, principalmente em idosos, e abre novas possibilidades para que futuros estudos possam compreender a demanda metabólica envolvida na manutenção da postura ereta / To remain standing for a certain period of time we periodically produce postural changes, which may favouring the adoption of more asymmetric postures. In face of the postural control system deterioration, it is possible that older people find it difficult to adopt more asymmetrical postures during daily life activities. In addition, changes in muscle activation pattern may increase energy cost to stand in asymmetric posture, which would lead to muscle fatigue and as consequence increase in fall risk in this population. Thus, postural changes during relaxed postures and the muscular demand necessary to perform such changes may differ among young and older adults, resulting in different energy cost. The present study investigated body weight asymmetries, muscle activations and energy cost in healthy young and elderly adults during sanding tasks with different constrains. Fifty-three young and sixteen elderly subjects remained at different positions while we recorded the body weight asymmetry over time (ADPm). All the elderly participants and twelve young adults undergone to electromyographic record of the thigh and leg muscles, and 7 subjects in each group to gas record in order to quantify the energy cost, oxygen consumption (VO2) and respiratory quotient (R) and registered heart rate. During quiet standing task, both age groups showed a slight and similar WDA (mean values around 5%). However, the elderly had difficulty in maintaining more asymmetric postures - they were less asymmetrical than young in tasks that required great WDA. In the relaxed position, most of the time the subjects remained in small asymmetry ranges, followed by a shorter period in more asymmetric postures. In general, muscle activation level was higher in the elderly, but they were able to recruit muscle in a similar way to young subjects. In addition, gastrocnemius activity increased proportionally to body weight support in both age groups - it was greater in the supportive limb in the most asymmetric postures. Although in this study the energy cost was not significantly affected by the asymmetry in body weight distribution in young and old individuals, it seems that the increased energy cost in the elderly is associated with an increase in muscle activity, which might explain the adoption of less asymmetric postures by these individuals. The results of this study raise the question of the possibility of higher energy expenditure in more asymmetric postures, especially in the elderly, and opens new possibilities for future studies to understand the metabolic demands during upright standing

TitleVVVVVVV VVVVV Objectives:VVV VVVVVVVVV VVVVVV Methods: VVVVVVVV VVVVVVVVV VVVVVVVVV VVVVVVVVV VVVVVVVVV VVVVVVVVV VV Results VVVVVVVVV VVVVVVVVV VVVVVVVVV V Key words Comparative analysis of chosen muscles in locomotion through shoulder girdle The aim of this study is to describe and to compare the canoe forward stroke with selected exercises performer during indoor training The research was conducted in an intentionally chosen sample of ten probands with high level of performance in whitewater slalom. We watched activity of ten selected muscles during canoe forward stroke, on simulator, diagonal pull, stretch of arms with elastic resistance, dumbbell pulls and pull ups by surface electromyography. Study evaluates intraindividual and subsequently interindividual the size of the muscle activation considering reference movement, forward stroke on flat water. The results proved similarities of the forward stroke and on simulator in terms of average muscle activation. M. latissimus dorsi shows higher activation during canoe forward stroke, on simulator, stretch of arms with elastic resistance, dumbbell pulls compared with other tested exercices. locomotion through the shoulder girdle, shot, canoeing, paddling, electromyography, muscular activity

Title Objectives: Methods: Results Key words Comparative analysis of chosen muscles in locomotion through shoulder girdle The aim of this study is to describe and to compare selected exercises performer during indoor training toward the canoe forward stroke. The research was conducted in an intentionally chosen sample of ten probands with high level of performance in whitewater slalom. We watched activity of ten selected muscles during canoe forward stroke, on simulator, diagonal pull, stretch of arms with elastic resistance, dumbbell pulls and pull ups by surface electromyography. Study evaluates intraindividual and subsequently interindividual the size of the muscle activation considering reference movement, forward stroke on flat water. The results proved similarities of the forward stroke and on simulator in terms of average muscle activation. M. latissimus dorsi shows higher activation during canoe forward stroke, on simulator, stretch of arms with elastic resistance, dumbbell pulls compared with other tested exercices. locomotion through the shoulder girdle, shot, canoeing, paddling, electromyography, muscular activity

Made available in DSpace on 2016-06-02T20:19:26Z (GMT). No. of bitstreams: 1 6632.pdf: 849903 bytes, checksum: 74e35d3e3b9a335c374c022b3e02fee6 (MD5) Previous issue date: 2015-02-26 / Financiadora de Estudos e Projetos / Introduction: Electromyography (EMG) contributes to the evaluation of disorders and pulmonary changes, since impairments in the respiratory muscles function are associated to the development of diseases. There are wide variety of methods and protocols applied to collect and analyze EMG obtained from respiratory muscles, demonstrating the absence of padronization. Objective: To identify the most commonly procedures applied to record surface EMG (sEMG) of inspiratory muscles in adults and elderly individuals, through a systematic review. Method: Studies published from January 1995 until March 2014 were searched through the keywords (breathing OR respiratory OR inspiratory) AND (electromyography OR EMG) AND (muscle activity OR muscular activity OR muscle activation OR muscular activation OR evaluation OR assessment OR effect) in the following electronic databases: Web of Science, PubMed, LILACS, EBSCO and Embase. Only studies evaluating sEMG in inspiratory muscles were included. Results: We identified 5410 titles and 64 studies, published in English, were included. A great variability of methods applied both record and process/analyze data were found. In general, the description presented by the studies is poor. Conclusion: The most commonly procedures applied were identified and the results obtained did not allow the synthesis of practical/clinical evidences which allow provide immediate recommendations for standardization of the methods to apply sEMG in inspiratory muscles. Thus, methodological studies with objective comparisons are fundamental to the advancement toward standardization. / Introdução: A eletromiografia (EMG) contribui para a avaliação de distúrbios e alterações pulmonares, uma vez que modificações no desempenho da musculatura respiratória estão associadas ao desenvolvimento de doenças. Há ampla variedade de métodos e protocolos empregados na coleta e análise do sinal EMG de músculos respiratórios, demonstrando a inexistência de padronização. Objetivo: Identificar os procedimentos mais comumente empregados na avaliação eletromiográfica de superfície (sEMG) de músculos inspiratórios em indivíduos adultos e idosos, por meio de uma revisão sistemática. Método: Estudos publicados no período de Janeiro de 1995 até Março de 2014 foram localizados a partir das palavras-chave (breathing OR respiratory OR inspiratory) AND (electromyography OR EMG) AND (muscle activity OR muscular activity OR muscle activation OR muscular activation OR evaluation OR assessment OR effect) nas seguintes bases eletrônicas: Web of Science, PubMed, LILACS, EBSCO e Embase. Apenas estudos que avaliaram sEMG em músculos inspiratórios foram incluídos. Resultados: Foram identificados 5410 títulos e, após a seleção, 64 estudos, publicados na língua inglesa, foram incluídos. Os resultados indicam grande variabilidade nos métodos empregados, tanto para obtenção quanto no processamento e análise dos sinais. Foram identificadas falhas na descrição dos procedimentos aplicados. Conclusão: Os procedimentos mais comumente aplicados foram identificados e os resultados obtidos não permitiram a síntese de evidência prática que viabilize fornecer recomendações imediatas quanto à padronização do uso da sEMG em músculos inspiratórios. Sendo assim, estudos metodológicos com comparações objetivas são fundamentais para o avanço no sentido da padronização.

La planche coréenne est une discipline de cirque exigeante d’un point de vue technique. Il s’agit d’une longue planche à bascule sur laquelle deux acrobates, placés à chaque extrémité, se catapultent continuellement pour effectuer des sauts acrobatiques. Les acrobates utilisent une technique spécifique pour le décollage et l’atterrissage. La planche coréenne, comme tout équipement de cirque, n’a pas de standard de fabrication et il existe une grande variété de planches. Les acrobates, les entraîneurs et les concepteurs d'équipements bénéficieraient d’avoir plus d'informations sur la biomécanique de la performance et sur la mécanique de la planche, afin d'améliorer le développement des techniques acrobatiques et la conception des planches. L’objectif de la thèse était de mieux comprendre l’interaction entre l’équipement de cirque et la performance acrobatique en planche coréenne. À cet égard, les quatre objectifs spécifiques étaient de : (1) Établir l’influence de la hauteur de saut, du participant, de la planche et de la technique de réception sur les forces d’impact et les taux de chargement; (2) Quantifier l’influence de plusieurs facteurs biomécaniques cinématiques sur la hauteur de saut; (3) Déterminer la différence de contribution musculaire et de durée des phases du mouvement entre acrobates débutants et acrobates élites; et (4) Caractériser mécaniquement différentes planches et mettre en évidence la contribution du renvoi de flexion de la planche sur la hauteur de sauts. Cette thèse présente l’ensemble des travaux effectués pour lier les caractéristiques de la planche au mouvement de l’acrobate. En effet, le mouvement de l’acrobate, sauter à grande hauteur, génère des forces élevées sur la planche lors de la réception, ce qui met en mouvement la planche. L’équipement ensuite permet un transfert de force vers l’acrobate qui s’élance. Finalement, ce dernier doit utiliser une technique optimale avec une synchronisation et une contribution musculaire précis, afin de gagner une hauteur suffisante pour la performance. Nos différentes études ont permis de montrer que le facteur qui influence le plus les forces d’impact et le taux de chargement lors de la réception est la hauteur de saut (40% d’influence relative). La force maximale mesurée est de 13.5 fois le poids corporel de l’acrobate, ce qui peut représenter un risque de blessure. La hauteur de saut est en majorité influencée par la vitesse verticale du centre de masse de l’acrobate-partenaire qui se réceptionne, de la vitesse verticale de la planche et de l’amplitude des hanches lors du décollage. Ces deux derniers paramètres peuvent être contrôlés par les acrobates ou les concepteurs de planche coréenne. Nous démontrons, de plus, que les acrobates débutants sont plus longs dans la préparation au décollage, le décollage et l’atterrissage comparativement aux acrobates experts. Cependant, il n’y avait pas de différence claire entre les débutants et les professionnels quant à l’activité musculaire lors du décollage et atterrissage, ce qui indique que la temporalité est sûrement plus importante que l’activité musculaire. Nous trouvons aussi que le renvoi de flexion (énergie élastique de la planche) est non négligeable (46 % d’influence relative) et contribue donc à la hauteur de saut. Finalement, le paramètre mécanique le plus important pour quantifier et comparer les planches est la raideur. Les quatre planches de l’étude ont une raideur qui varie entre 12.2 kN/m et 19.6 kN/m. Ce paramètre peut probablement guider les futures conceptions de planche. Collectivement, ces quatre études mettent en évidence que la synchronisation temporelle du mouvement des acrobates et du mouvement de la planche est l’élément crucial dans cette discipline. / Korean teeterboard is a technically demanding circus discipline. The apparatus resembles a seesaw, and two acrobats take turns jumping vertically, performing complex acrobatic figures and landing back on the apparatus. Acrobats use a specific technique during take-off and landing. Furthermore, like most circus equipment, there are no standards regarding the design of the teeterboard and there is a wide variety of teeterboards. Acrobats, trainers and equipment’s designers would benefit to know more about the relationship between the biomechanics of the performance and the mechanics of the board. This understanding would help improving acrobatic techniques and optimize the design of teeterboards. The purpose of the thesis was to better understand the interaction between the circus equipment and the acrobats’ performance in Korean teeterboard. To this end, this thesis was divided into four specific goals: (1) Define the influence of the jump height, the teeterboard and the landing technique on impact forces and loading rates; (2) Quantify the influence of various kinematic factors to the jump height; (3) Determine the differences between expert and novice acrobats with respect to muscular contribution and duration of the phases of the movement ; and, (4) mechanically characterize different types of teeterboards and highlight the contribution of the recoil effect to the jump height. This thesis covers the work carried out to link the characteristics of the teeterboard to the movement of the acrobat. The movement of the acrobat, i.e., jumping at high height, generates high forces during landing, which set in motion the board. The equipment then enables the transfer of this force to the other acrobat taking-off. This acrobat should use an optimal technique with a precise timing and muscular contribution, to gain sufficient height for their performance. This body of work demonstrated that the most important factor influencing the impact forces and loading rates was jump height (40% of relative influence). Maximal recorded force was 13.5 times the acrobat’s bodyweight, raising concerns about risk of injury. Jump height was mainly influenced by the vertical velocity of the center of mass of the acrobat landing, the vertical velocity of the teeterboard and the hip range of motion at take-off. The last two parameters can be controlled by acrobats, trainers, or designers of Korean teeterboard. We also found that novice acrobats are longer in the following phases: preparation for take-off, take-off, and landing. However, there was no clear difference in muscular amplitude during take-off and landing between novice and professional acrobats. This indicates that timing may be more important than muscular amplitude. We showed that recoil effect (elastic strain energy of the board) strongly contributed to the jump height (46% of relative influence). Finally, the most important mechanical parameter to quantify and compare teeterboards was the stiffness. The stiffness of the four teeterboards analyzed in this study ranged from 12.2 kN/m to19.6 kN/m. This result can guide future designs of teeterboard. The results from this thesis highlight the fact that temporal synchronization of the movement from both acrobats and the movement of the board is crucial in this discipline.