Introducción: La Encuesta Nacional de Nutrición y Salud (ENNSA) del 2010 menciona que el IMC en los adolescente de 15 años se encontró que el 33,78% de los escolares evaluados se encuentran en condición de obesidad, el 32,45% en condición normal, el 23,84% en condición de sobrepeso, un 5,96% en condición delgadez y el 3,97% en condición de riesgo de delgadez, otros estudios destacan un gran aumento del sobrepeso y obesidad en niños y adolescentes de diversas regiones del mundo inclusive en el Perú. Los efectos del sobrepeso y la obesidad abarcan alteraciones hormonales, metabólicas, ortopédicas y psicológicas, como consecuencia de este conjunto de anomalías el trabajo ventilatorio se altera teniendo la necesidad de una intervención precoz de la Fisioterapia, no hay estudios que muestren trabajos de fisioterapia a través de ejercicios respiratorios en adolescente. Objetivo: Determinar la relación de los ejercicios respiratorios y el IMC en estudiantes de 12 – 13 años de secundaria de la I.E Nicolás Copérnico - Lima - San Juan de Lurigancho – Diciembre 2014. Diseño: Diseño de estudio experimental de subtipo cuasiexperimental. Institución: Escuela Académico Profesional de Tecnología Médica Terapia Física y Rehabilitación Facultad de Medicina San Fernando, Universidad Nacional Mayor de San Marcos. Participantes: La muestra está constituida por 116 alumnos de 12 a 13 años de la I.E Nicolás Copérnico - Lima - San Juan de Lurigancho, seleccionados a través del método de muestreo no probabilísticos del tipo casual o incidental. Intervenciones: Se aplicó el plan de tratamiento de entrenamiento muscular respiratorio para niños de 12-13 años de la I.E Nicolás Copérnico SJL. Resultados Según la variación del volumen de inspiración máxima antes y después del programa de ejercicios respiratorios encontramos que ha predominado la condición de MANTENER el volumen de inspiración máxima sostenida en el grupo de DELGADEZ un 68%, en el grupo NORMAL un 73%, en el grupo de SOBREPESO un 68% la condición de mantenerse y en el grupo de OBESIDAD un 56%. Conclusiones: En el estudio realizado se concluye que no existe relación positiva de los ejercicios respiratorios y el índice de masa corporal, sin embargo, la mayoría de la población de estudio se mantuvo en el volumen de inspiración máxima sostenida, esto puede revelar un efecto preventivo. / Tesis

Ces pages font un état des lieux des travaux réalisés au sein du département de médecine générale de 2004 à 2011 sur l'hypovitaminose D, sa fréquence, ses facteurs de risques, son lien avec les douleurs musculo-squelettiques diffuses et chroniques chez les adultes jeunes. De ces travaux et de la revue de la litéérature, il ressort quelques notions importantes et méconnues. Les personnes qui cnsultent un médecin généraliste ont des taux sérique de vitamine D beaucoup plus bas que les taux trouvés dans les groupes de volontaires sains recrutés pour les grandes études comme Suvimax ou l'enquête nationale nutrition santé (ENNS). Les taux retrouvés dans nos travaux sont identiques à ceux trouvés dans les populations émigrées des pays développés et dans les populations des pays où le soleil est évité, mais nos populations, elles, sont ordinaires hommes comme femmes.Les facteurs de risques de l'hypovitaminose sont retouvés dasn nos populations : les vêtements couvrants, le phototype, l'obésité, pas d'exposition solaire, pas de sport en extérieur, pas de vacances au soleil, la CMU marqueur de précarité. Une des conséquences sont des douleurs musculaires et osseuses, chronqiues, diffuse avec une moindre qualité de vie physique. Le traitement des déficits améliore les patients douloureux que nous avons trouvé très carencés. Ces patient consomment beaucoup de soisns et leur prise en charge pourrait réduire d'au moins 50 % leur consommation de soins. Il y a urgence à prendre en considération ce p^roblème de santé publique car 100% des consultants adultés âgés entre 18 et 50 ans, homme et femme, douloureux chroniques, ont un déficit (vitamine D <20 ng/ml ou 50 nmol/l), et plus de 25% ont un déficit sévère (vitamine D <10 ng/l ou 25 nmol/l). / Hypovitaminosis D is common in populations which consult GP's. Manu studies have been conducted which revealed high prevalence of severe hypovitaminosis in young people. risk factors were covered clothes, high BMI, dark phottype, precarity, no sunhbathing, no sun holidays, no sport outdoor. Quality of life was correlated with vitamin D levels. Patients with chronic musculo skeletal pains had very low level of vitamin D < 10 ng/ml for 25%. The supplementation cured the pains for more than 50 % of the patients and decreased the consumption of medicines and care. It will be be very important to consider this problem of public health for young people.

Conception et évaluation d’un modèle biomécanique, éléments finis, patient-spécifique, du pied humainApplications en podologie, orthopédie et diabétologieLe pied est une des structures les plus complexes du corps humain. Avec 28 os, 33 articulations et une centaine de structures ligamentaires, cette entité poly articulée est le résultat d’une hyperspécialisation ayant contribué à faire de l’homme l’unique primate totalement bipède. Quelque soit le relief, quelque soit le mouvement en cours, le pied transmet au tibia le bon vecteur force afin de finaliser le geste de la manière la plus précise et économe en énergie possible dans l’objectif de préparer l’action des segments sus jacents. Ainsi, en cas de lésion d’une des structures, l’ensemble du complexe pied doit pouvoir s’adapter, si ce n’est pas le cas, les tissus mous, les articulations ou les os seront fragilisés et verront leur fonction propre au sein de ce complexe altérée.Prédire l’adaptation du pied à une modification structurelle, tissulaire, neurologique ou fonctionnelle est un enjeu important dans l’estimation du risque lésionnel.Afin d’initier une réponse à ces problématiques, nous avons décidé au cours de cette thèse de modéliser le pied humain avec des outils mathématiques de simulation biomécanique. Dans un premier temps, un modèle tridimensionnel musculo-squelettique du pied a été reconstruit à partir d’imagerie scanner. Le pied polyarticulé en multicorps rigides obtenu possède des articulations uniquement contraintes par les ligaments et contacts osseux. Les muscles ont été implémentés afin de piloter le modèle en dynamique directe. Enfin, les tissus mous comme les volumes musculaires, le gras et la peau ont été maillés en éléments finis. L’utilisation d’un environnement de programmation multi-physique open source (Artisynth) a permis de coupler la modélisation musculo-squelettique et éléments finis.• L’adaptation du pied au sol en orthostatisme a été évaluée par comparaison des cartographies de pression d’une mise en charge simulée avec la mise en charge réelle du sujet.• Le contrôle moteur du pied en chaine ouverte par l’activation des muscles extrinsèques a été évalué en comparant la cinématique du modèle biomécanique pilotée par électromyographie avec la cinématique capturée en laboratoire sur un mouvement d’abduction – adduction.• Nous avons ensuite cherché à comprendre comment une arthrodèse de cheville modifie la cinématique du pied à la contraction musculaire, l’objectif étant d’aider au réglage chirurgical du geste.• Enfin nous avons utilisé les dernières avancées sur la physiologie de la plaie de pression afin de prédire le risque d’ulcération sur un pied neuroarthropatique diabétique par simulation numérique.Le modèle ainsi que les routines de simulations mis en place nous permettent d’avoir un des modèles les plus aboutis du pied humain utilisant aussi bien des données physiques externes comme les données baropodométriques, les données d’analyse quantifiée du mouvement ou encore les données électromyographiques. Ce modèle permettra par l’intermédiaire d’outils de mesh-matching d’obtenir des modèles patients spécifiques. Les domaines d’applications porteront sur l’aide au geste chirurgical, la prévention des risques d’ulcération, l’analyse avancée des relations entre le pied et le membre inférieur, mais aussi l’aide à la conception de prothèse en orthopédie classique et en mécatronique. / Biomechanical modeling of the human foot. Application to the healthy and pathological subject.The foot is one of the more complex structures of the human body. With 28 bones, 33 joints and a hundred ligamentous structures, this articulated entity is the result of a hyper specialization that makes humans the only obligate bipedal primates. Whatever the terrain, whatever the current movement, the foot transmits to the tibia the right force vector to finalize the gesture in the most precise and efficient manner and prepares the action of the lower limb. Thus, in case of injury to one of the structures, the whole foot complex must adapt if it is not the case, soft tissues, joints or bones are fragile and will have their own function within this complex altered .Predicting the foot’s adaptation of a structural, tissue, neurological or functional modification is an important issue in estimating the risk lesion on locomotion, in the design of therapeutic footwear and orthotics of the degenerative foot, but also in the future of this complex in situations where the boundary conditions change like working in microgravity or foot exoskeleton coupling.To initiate a response to these problems, we decided during this thesis to model the human foot with mathematical tools for biomechanical simulation. Initially, a musculoskeletal three-dimensional model of the foot was reconstructed from computed tomography. The multi-articulated foot joints constraints obtained by ligaments and bone contact. The muscles have been implemented to control the model in direct dynamic. Finally, the soft tissues such as muscle volume, fat and skin were meshed into finite elements. Using a multi-physics open source programming environment (Artisynth) allowed to couple musculoskeletal modeling and finite elements.• Adapting the foot on the ground in upright posture was evaluated by comparing the pressure maps at a simulated load setting with the actual loading pressure map of the subject.• The motor control of foot in opened chain by activation of the extrinsic muscles was assessed by comparing the kinematics of the biomechanical model piloted by electromyography with kinematics captured in the laboratory on a movement of abduction - adduction.• We then sought to understand how an ankle arthrodesis alter the kinematics of the foot muscle contraction, with the aim of helping the surgical setting gesture.• Finally, we used the latest advances in the physiology of a pressure ulcer to predict the risk of ulceration on diabetic foot with Charcot neuro arthropathy by numerical simulation.The model and simulation routines in place allow us to have one of the most successful models of the human foot using both external physical data like pedobarographic data, motion analysis data or electromyography data. This model will allow through mesh-matching tool to obtain specific patient models. The fields of applications will focus on assisted surgery, prevention of ulceration, advanced analysis of relations between the foot and the leg, but also will help the prosthesis design in orthopedic and mechatronics.

La robotique constitue une solution prometteuse pour développer des systèmes d'assistance visant à améliorer l'autonomie et les conditions de vie des personnes dépendantes. Ainsi, de nombreuses recherches sont menées actuellement à travers le monde pour concevoir et développer des robots portables ou exosquelettes, en tant que dispositifs d'aide à la mobilité pour augmenter les capacités motrices des sujets porteurs, ou comme auxiliaires de rééducation neuro-musculaire. Cette thèse vise le développement des modèles de connaissances nécessaires pour la mise en oeuvre de commandes assistives d'un exosquelette de l'articulation du genou, notamment celles basées sur l'intention du sujet porteur. Cet exosquelette est destiné à l'assistance des mouvements de flexion/extension du genou pour des personnes souffrant de pathologies du genou, ou pour le renforcement musculaire et la rééducation de sujets âgés ou hémiparétiques. Pour l'estimation de l'intention de mouvement du porteur, nous proposons modèle musculo-squelettique polynomial, complété par un modèle muscle-tendons de type Hill et le modèle bi-linéaire de Zajac pour modéliser la dynamique d'activation et de désactivation musculaire. Le modèle musculo-squelettique polynomial proposé offre le même niveau de réalisme et de précision qu'un modèle musculo-squelettique générique anatomique, sans nécessiter l'emploi de méthodes d'optimisation gourmandes en temps de calcul. Dans cette thèse, nous proposons un ensemble de trois commandes assistives destinées à guider ou à assister, via l'exosquelette, un sujet dans un contexte d'assistance à la rééducation en mode actif-aidé: La première, basée sur la passivité, exploite les propriétés physiques de l'exosquelette et du sujet porteur pour stabiliser asymptotiquement l'ensemble exosquelette-membre inférieur du porteur. Les paramètres du contrôleur sont ajustés automatiquement en fonction de la contribution du sujet au mouvement. A travers cette commande, l'exosquelette développe un couple correctif pour guider le genou vers la trajectoire de référence ou son voisinage. La seconde commande introduit une saturation pour maintenir le couple d'assistance dans un intervalle donné, garantissant ainsi la sécurité du sujet porteur. Cette commande garantit aussi des mouvements à des vitesses raisonnables et une convergence vers la trajectoire de référence. La deuxième loi de commande est complétée par une fonction permettant de moduler le couple d'assistance en fonction de la phase de rééducation. Enfin, la troisième commande proposée vise à maximiser la transparence de l'exosquelette pour éviter d'altérer les mouvements naturels du sujet porteur. Elle exploite la dynamique d'interaction induite par les mouvements relatifs du sujet porteur par rapport à l'exosquelette dus aux compliances intrinsèques de l'ensemble exosquelette-membre inférieur. Ces commandes ont été évaluées sur un sujet volontaire sain âgé de 29 ans, en considérant les modes d'assistance passif et actif-aidé. L'analyse des résultats expérimentaux montre de bonnes performances en termes de précision de poursuite de trajectoire, de robustesse vis-à-vis des incertitudes paramétriques et des perturbations externes. Ces résultats montrent également des propriétés importantes comme la sécurité du sujet porteur, le suivi précis de l'intention du porteur, l'assistance adaptative pour la rééducation active et la transparence de l'interaction exosquelette-porteur / Nowadays, robotics constitutes a promising solution to develop assistive systems to improve autonomy of dependent people during everyday activities. Thus, much research is being conducted currently worldwide to design and develop wearable robots or exoskeletons as assistive devices for mobility in order to improve the capabilities of the wearer. These devices can also be used during neuromuscular rehabilitation processes. This thesis aims to develop models necessary for the implementation of subject's intention wearer assistive control strategies using a knee joint exoskeleton. In order to estimate the movement intention of the wearer, we propose a Hill- Zajac based musculoskeletal model. This musculoskeletal model provides a high level of realism and accuracy compared to an anatomical generic musculoskeletal model without requiring the use of optimization methods techniques that are generally computational effort consuming. Three assistive control strategies are developed in this thesis to assist the wearer in a context of assistance and rehabilitation. In this thesis, we propose a set of three assistive commands to guide or assist through the exoskeleton, a subject in the context of rehabilitation assistance to active-assisted method: The first, based on passivity, operates the physical properties of the exoskeleton about the wearer and to stabilize the lower assembly asymptotically exoskeleton-member carrier. The first one is based on passivity and uses the physical properties of the exoskeleton and the wearer to stabilize asymptotically the human- lower-limb exoskeleton system. The second one introduces a saturation threshold to maintain the assistive torque in a given interval, ensuring the safety of the wearer. The third one aims to maximize the transparency of the exoskeleton to avoid altering the natural movements of the wearer. It uses the interaction dynamics induced by the relative movements between the wearer and the exoskeleton. These control strategies were evaluated on a 29-year-old healthy volunteer subject. The analysis of the experimental results shows satisfactory performances in terms of trajectory tracking accuracy, robustness with respect to parametric uncertainties and external disturbances. The results show also a good accuracy in the human intention detection and an adaptive support for active rehabilitation and transparent human-robot interaction

Le vieillissement de la population dans notre société moderne va entraîner de nouveaux besoins pour l’assistance aux personnes âgées et pour la réhabilitation. Les exosquelettes sont une piste de recherche prenant de plus en plus d’importance pour répondre à ces nouveaux challenges. Deux de ces challenges sont, la réalisation d’un contrôle naturel pour l’utilisateur et la sécurité. Cette maîtrise cherche à répondre à ces deux problématiques. Nous avons donc développé un outil de travail informatique utilisant les décharges électriques produites par les neurones moteurs pour contracter les muscles et un modèle des os et des muscles du bras. Cet outil utilise la librairie informatique ROS et OpenSim. Elle permet de connaître la force et le mouvement développés par le coude. De plus, un autre outil informatique a été développé pour optimiser le modèle des os et des muscles du bras pour le personnaliser à l’utilisateur pour un meilleur résultat. Une carte d’acquisition utilisant des électrodes de surface pouvant être reliées avec un ordinateur par USB et compatible avec ROS a été développée. Pour tester les algorithmes développés, un exosquelette pour le coude utilisant un actionneur compliant et contrôlé en force a été conçu. Pour compenser le poids de l’exosquelette et l’effet d’amortissement passif de l’actionneur, une compensation de gravité dynamique a été développée. Finalement, des expérimentations ont été menées sur l’efficacité de l’optimisation du modèle et sur l’exosquelette avec les différents algorithmes.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Os marcadores de estresse músculo-esqueletal (MSMs), assim denominados, surgem pela primeira vez em 1995 no trabalho pioneiro de Hawkey e Merbs. De lá pra cá, diversos estudos se prestaram a aprimorar o método desenvolvido pelos pesquisadores e, ainda, associar de maneira mais concreta os graus de desenvolvimento de enteses a atividades desenvolvidas ao longo da vida de um indivíduo. Sob tais circunstâncias, buscamos neste trabalho a verificação da implementação de uma metodologia de análise revisada, testada e aprimorada dos marcadores de estresse músculo-esqueletal e a possibilidade de correlação entre os graus de desenvolvimento das enteses estudadas com as possíveis atividades desenvolvidas pelos indivíduos analisados, provenientes do sambaqui costeiro catarinense Jabuticabeira II (JAB-II). A escolha pela análise dos remanescentes ósseos deste sítio decorreu da vasta informação disponível em relação aos mesmos e ao sítio em si, provindos de outros trabalhos desenvolvidos previamente. Assim, estudos de paleopatologia e arqueologia possibilitaram melhores interpretações dos resultados obtidos pelas análises de MSMs. Neste trabalho procuramos adaptar a metodologia desenvolvida por Mariotti (2004,2007) para amostras antigas (mais de 2000 anos atrás) e de baixa conservação. Além disso, realizamos inferências sobre as atividades desenvolvidas pelos indivíduos sepultados em JAB-II, a divisão de tais atividades baseada em sexo e faixa etária, a avaliação dos graus de entesopatias (lesões na região entesal que vão além do desenvolvimento saudável de uma entese) e sua frequência na população estudada, a correlação do grau de desenvolvimento de entese com outro marcador muito comum em estudos de paleopatologia, a osteoartrose e, por fim, estabelecer, ainda que de forma tímida, o perfil físico típico do indivíduo de JAB-II, baseado na avaliação de todas as enteses disponíveis para estudo (1067 enteses disponíveis entre homens e mulheres adultos). A metodologia de estudo se mostrou eficaz, feitas às devidas adaptações metodológicas, com aprovação da proponente do método original. O erro intra-observacional, valor de erro de concordância calculado entre duas análises para o mesmo conjunto de enteses, com intervalo de tempo longo (3 meses), pelo mesmo avaliador, ficou dentro dos padrões aceitáveis pela comunidade científica (20%). Verificou-se, ainda, grande prevalência de alta robustez para a totalidade de enteses avaliadas. Quando analisados os complexos funcionais (conjunto de músculos e articulações envolvidas na realização de um movimento) verificou-se também alta prevalência de robustez elevada, com destaque para os complexos dos membros inferiores, antes tidos como pouco requisitados devido à baixa prevalência de osteoartrose nos mesmos. A avaliação de complexos funcionais é mais efetiva para a correlação dos graus de robustez com atividades realizadas no dia-a-dia já que várias destas envolvem a ação de mais de um músculo para a sua realização. Homens e mulheres apresentaram diferenças estatisticamente significantes com relação ao desenvolvimento de suas enteses, sendo os homens mais robustos que as mulheres. O mesmo verificou-se em relação às faixas etárias, sendo os indivíduos mais velhos mais robustos. Com relação às entesopatias, não verificamos diferenças na prevalência de entesofitóses tanto quanto a sexo quanto a faixas etárias. Com relação às lesões líticas (outra entesopatia analisada) verificaram-se diferenças estatisticamente significantes entre os sexos, com maior prevalência de tal marcador na parcela masculina. Já em relação às faixas etárias, não se verificaram diferenças estatisticamente relevantes. Por fim, por ser um traço esqueletal associado à atividade física, procuramos relacionar as osteoartroses previamente estudadas na amostra com os graus de desenvolvimento de entese avaliados neste trabalho. Não foram encontradas correlações de qualquer natureza entre os dois marcadores mas, devemos chamar atenção ao elevado número de enteses nas quais se verificaram alta robustez com baixo nível de osteoartrose. Tal observação poderia indicar possíveis relações de proteção da articulação devido à atividade física intensa, inferida indiretamente pelo grau de desenvolvimento da entese. Podemos assim supor que o indivíduo sepultado em JAB-II, independentemente de sexo e idade, seria um indivíduo robusto, de musculatura avantajada, compatível com o grau de atividade física desempenhada possivelmente em seu dia a dia e com seus possíveis hábitos alimentares / The so called Musculo-Skeletal Stress markers (MSM) enriched the wealth of possibilities to infer past life styles since 1995 with the Hawkey and Merbs work on Inuit populations. Since then, many studies tried to improve the method developed by these two researchers and associate the development of the entheses to certain physical activities . Under these circumstances, in this work we tested, modified and adapted this method to analyze MSM, and the possibility to correlate the degrees of development of the entheses with the possible activities performed by the individuals of individuals excavated from the costal Shellmound of Santa Catarina (BR) called Jabuticabeira II (JAB-II). We choose to analyze the osteological collection from this site due to extensive previous information available on its burials and on the site itself, because palaeopathology and archaeology studies render better interpretations of the results obtained by the MSM analyses. In this work, we adapt the methodology developed by Mariotti (2004,2007) to ancient samples (more than 2000 years old), with low state of preservation. We also used MSM to infer about the daily activities performed by the people buried at JAB-II, the division of labour based on sex and age, the evaluation of the severity of enthesopaties (pathological lesions on the enthesis) and it´s frequency in the population studied, the correlation between the enthesis´ severity and osteoarthrosis, and, finally, establish, even if in a very cautious way, the typical body type profile of the JAB-II population, based on the evaluation of the 1067 entheses available for analysis. The method adopted was effective as long as adapted to our sample, with the acceptance of the method developer (Mariotti). The intra-observer error, concordance error value between two analyses, three months apart, of the same set of enthesis, performed by the same observer is acceptable by the scientific community (20%). Were observed a high prevalence of increased robusticiy for all entheses evaluated individually and grouped into functional complexes (set of muscles and joints involved in the performance of a given movement). However, contrary to earlier interpretations based on osteoarthritis, the lower limbs must have been more requested than the upper ones. The evaluation of functional complexes is more effective for the correlation between robusticity and daily activities, given the requirement of more than one muscleusually used to perform one single movement. We found statistically significant differences between the male and female samples for the development of the entheses, with the male portion presenting more entheses with high robusticity than females. The same was observed within age classes, where older adults present higher enthesis robusticiy. We did not find significant statistical differences in the prevalence of enthesophytic formations between sexes and age classes. For the osteolytic formations we found significant statistical differences between the sexes, with higher prevalence among males, whereas no differences were observed between the age classes. Finally, for being an skeletal marker associated to physical activity, we tried to correlate osteoarthrosis (previously studied in this sample) with the developmental degrees of the entheses. No correlations of any nature were found between the two markers. Nevertheless,the elevated number of entheses with high robusticity and low levels of osteoarthrosis suggest that frequent and/or intense physical activity may protect the joints from osteoarthritis

O músculo estriado esquelético é uma entidade extremamente versátil, capaz de alterar seus padrões e características fenotípicas sob diversas condições, tais como, atividade neuromuscular, estimulação elétrica, idade, atividade hormonal e exercício físico. Sabe-se também que o balanço entre estímulos atróficos e hipertróficos controlam diretamente a massa muscular do indivíduo e estas variações implicam diretamente não apenas sobre o volume muscular, mas também conteúdo de proteínas e produção de força. Neste sentido, a atrofia muscular (perda de massa muscular) é caracterizada tanto pela diminuição na área de secção transversa das fibras musculares, como também pelo decréscimo no conteúdo de proteínas miofibrilares e consequente redução do volume muscular. Esta atrofia muscular pode ocorrer sob diversas condições clinicas e/ou patológicas, acarretando na diminuição ou perda da massa magra levando à uma consequente diminuição da atividade física, da qualidade de vida e inclusive pior resposta ao tratamento, ocasionando consequentemente aumento da mortalidade. Fica claro desta maneira, que, os métodos que visam a prevenção ou tratamento à atrofia muscular tem importante relevância clínica em muitos grupos de pacientes, além de ser um importante fator contribuinte na qualidade de vida e autonomia destes indivíduos. Com isso o estudo de determinados tratamentos que combatam a atrofia muscular torna-se de vital importância, dentre os quais, vem ganhando destaque o &#x3B2;Hidroxi &#x3B2;Metilbutirato (HMB). Deste modo teve-se como objetivo neste trabalho verificar a efetividade do HMB em prevenir a atrofia muscular induzida por dexametasona (DEXA). Para isto, foram utilizados 32 animais da linhagem Wistar com idade de 60 dias, distribuídos nos seguintes grupos: Grupo Experimental Placebo (GEP), n=8, tratados por 10 dias consecutivos com gavagem e injeção intraperitoneal, ambas contendo apenas solução salina; Grupo Experimental Dexametasona (GED), n=8, tratados por 10 dias consecutivos com gavagem contendo solução salina e injeção intraperitoneal contendo dexametasona; Grupo Experimental HMB (GEH), n=8, tratados por 10 dias consecutivos com gavagem contendo HMB e injeção intraperitoneal contendo solução salina; e Grupo Experimental Dexametasona + HMB (GEDH), n=8, tratados por 10 dias consecutivos com gavagem contendo HMB e injeção intraperitoneal contendo DEXA. Os animais foram acondicionados em caixas coletivas com 4 animais por caixa, com comida e agua à vontade em sala climatizada com temperatura de 22o e respeitando o ciclo de 12 horas claro/escuro. Finalizados os dez dias de tratamento, os animais foram eutanasiados para a coleta do material. Após as análises, as médias dos grupos para peso corpóreo dos animais, peso muscular e os valores da morfometria foram todos submetidos ao teste One-Way ANOVA, seguidos do Teste de Tukey, sendo o valor considerado estatisticamente significante de p<0,05. Ao final pôde-se concluir que, no delineamento experimental aqui aplicado, o HMB não foi capaz de atenuar ou prevenir a perda de peso corporal induzida pela DEXA, sendo que o efeito anticatabólico esperado pelo HMB não repercutiu no musculo EDL, contudo foi capaz de prevenir a atrofia no musculo sóleo. / The skeletal muscle is an extremely versatile entity, able to change their patterns and phenotypic characteristics under various conditions such as neuromuscular activity, electrical stimulation, age, hormonal activity and exercise. It is also known that the balance between atrophic and hypertrophic stimuli directly control the muscle mass of the individual and these changes directly affect not only on muscle volume, but also protein content and production strength. In this sense, muscle atrophy (loss of muscle mass) characterized by both, the decrease in cross-sectional area of muscle fibers, but also by decreasing the content of myofibrillar proteins and consequent reduction in muscle volume. This muscle atrophy may occur in various pathological conditions, resulting in decrease or loss of lean body mass leading to a consequent reduction in physical function, quality of life and even worse response to treatment, thus leading to increased mortality. It is clear in that way that the methods aimed at preventing or treating muscle atrophy has important clinical relevance in many groups of patients, as well as being a major contributing factor in the quality of life and autonomy of individuals. Thus, the study of certain treatments that combat muscle atrophy become of vital importance, among which highlight is winning the &#x3B2;-hydroxy-&#x3B2;-methylbutyrate (HMB). Thus, it is aimed in this study to assess the effectiveness of HMB to prevent muscle atrophy induced by dexamethasone (DEXA). For this, we used 32 Wistar animals aged 60 days, distributed in the following groups: experimental group Placebo (GEP), n = 8, treated for 10 consecutive days with gavage and intraperitoneal injection, both containing only saline. Experimental group Dexamethasone (GED), n = 8, treated for 10 consecutive days with gavage containing saline and intraperitoneal injection containing dexamethasone. Experimental group HMB (GEH), n = 8, treated for 10 consecutive days with gavage containing HMB and intraperitoneal injection containing saline solution and Experimental Group Dexamethasone + HMB (GEDH), n = 8, treated for 10 consecutive days with gavage containing HMB and intraperitoneal injection containing DEXA. The animals were placed in collective boxes with 4 animals per cage with food and water at will in a room with 22o temperature and respecting the light / dark 12-hour cycle. Completed the ten days of treatment, the animals were euthanized to collect the material. After the analysis, the mean body weight to groups of animals, muscle weight and values of morphometry were all subjected to one-way ANOVA followed by Tukey test, with the amount considered statistically significant at p <0.05. At the end, it could be concluded that the experimental design applied here, the HMB was not able to mitigate or prevent the loss of body weight induced by DEXA, and the anti-catabolic effect expected by HMB not reflected in the EDL muscle, but was able to prevent atrophy in the soleus muscle.

L'étude de la biomécanique du geste sport a pour double objectif d'améliorer la performance et de minimiser le risque de blessures. De multiples études ont appliqué les principes de la biomécanique au mouvement du swing de golf. Toutefois, des biais méthodologiques et un manque de consensus ont conduit à des résultats parfois contradictoires. Ainsi, l'objectif premier de cette thèse a été d'effectuer une analyse exhaustive de l'état de l'art de la biomécanique appliquée au swing de golf. Le second objectif a été de concevoir et de mettre en place un protocole expérimental qui permette l'analyse du swing de golf. Et le troisième objectif a été de développer les modèles et analyses permettant l'étude du swing de golf. Cette partie a été effectuée à l'aide du développement d'un modèle musculo-squelettique via le logiciel OpenSim.34 joueurs ont été analysés dans le cadre de cette thèse. Les analyses ont porté sur de multiples éléments : géométriques, cinématiques, dynamiques et énergétiques. Différents critères ont été pris en compte, dont certains couramment pris en compte dans l'analyse du swing de golf (e.g. X-factor), dans l'analyse du mouvement (e.g. dynamique articulaire), mais aussi de nouveaux critères tels que le moment moteur ou le moment cinétique moteur.Des perspectives en termes de transferts vers les équipes médicales et les entraîneurs ont été proposées. / Studying biomechanics aspects of sport movements is aiming at improving performance and reducing injury risk. Several studies have used biomechanics concepts to study golf swing. However, several methodological biases and the lack of consensus have driven to contradictions. Thus, the first objective of this thesis was to do an exhaustive literature review of the biomechanics applied to golf swing. The second objective was to establish an experimental protocol for studying golf swing. And the third objective was to develop models and analysis to study golf swing. This part was done by a musculoskeletal model developed with OpenSim software.34 golf players have been analyzed for this thesis. Those analyses tackled multiples aspects : geometries, kinematics, kinetics and energetics. Several criteria have been taken into account, some from golf swing analysis (e.g. X-factor), from movement analysis (e.g. articular kinetics) and some new ones such as motor moment and motor kinetic moment.Perspectives for transferring results to medical staff and coaches were proposed.

O músculo estriado esquelético apresenta em sua constituição células satélites (CS) que se encontram em estado quiescente localizadas entre o sarcolema e a lâmina basal das fibras musculares. As CS podem ser ativadas, diferenciando em mioblastos, contribuindo para regeneração e/ou crescimento do tecido muscular. Os Fusos neuromusculares são mecanorreceptores localizados no interior dos músculos esqueléticos considerados a unidade contrátil reguladora, monitorando a velocidade e duração do alongamento do músculo. Está composto de fibras intrafusais (FIF), circundadas por uma bainha de tecido conjuntivo e encontra-se paralelo às fibras extrafusais. A desnervação promove alterações no músculo esquelético, tanto em CS, quanto nos fusos neuromusculares. Este trabalho analisou quantitativamente as FIF e a proliferação de CS em músculos esquelético de ratos desnervados por longo período. Foram utilizados ratos Wistar. Os animais foram divididos em grupos desnervados e controle. Os músculos Sóleo e Extensor longo dos dedos (EDL) foram desnervados experimentalmente. Após os períodos de 0, 12, 16, 19, 30 e 38 semanas, os músculos foram dissecados, removidos e preparados histológicamente. A porcentagem de CS em músculos imediatamente após desnervação aumenta em relação ao músculo normal e depois decresce em ambos os músculos. Durante o progresso do tempo de desnervação ocorreu um aumento no número de FIF, se comparado com o grupo normal. O número de CS diminui significantemente entre os períodos de desnervação, em ambos os grupos. Nos músculos estudados quanto menor a porcentagem de CS maior é o número de FIF e, aumentando o tempo de desnervação, diminui o número de CS. Em relação às FIF, no grupo controle com o aumento do tempo, o número de fibras não se altera. Já para o grupo experimental, com o aumento do tempo de desnervação, diminui o número de CS e aumenta o número de FIF significantemente. Concluimos então que nos músculos desnervados por longo período ocorre diminuição na porcentagem de células satélites e aumento no número de FIF. Finalmente nossos resultados sugerem que entre 16ª e 19ª semana pós-desnervação encontra-se o melhor período para reinervação de um músculo desnervados. / The skeletal muscle consists of satellite cells (SC) which are in a quiescent state located between the sarcolemma and basal lamina of the muscle fibers. The SC can get activated, differentiating into myoblasts, contributing to regeneration and/or growth of muscle tissue. The neuromuscular spindles are mechanoreceptors located within the skeletal muscle and are considered as contractile regulatory unit, monitoring the speed and duration of muscle stretching. It is composed of Intrafusal muscle fibers (FIF), surrounded by a sheath and is parallel to extrafusal fibers. Denervation cause changes in skeletal muscles both in the CS and neuromuscular spindles. This study analyzed quantitatively the FIF and the proliferation of CS in rat skeletal muscle, denervated for long period. We used Wistar rats to perform this study. The animals were divided into control and denervated groups. The soleus and extensor digitorum longus (EDL) were denervated experimentally. After periods of 0, 12, 16, 19, 30 and 38 weeks, the muscles were dissected, removed and were prepared for histological analysis. The percentage of SC in muscles immediately after denervation, increases in relation to normal muscle and later decreases in both the groups. During the process of denervation, there was an increase in FIF when compared with normal group. The number of SC reduces significantly between the periods of denervation in both the groups. In the muscles studied, the smaller the percentage of SC, higher is the number of FIF and increase in the duration of denervation, reduces the number of SC. As for FIF, with the increase in time in control group, the number of fibres was unaltered. However, in the experimental group, with increase in the time of denervation, the number of SC decreases while there is increase in the number of FIF significantly. We thus conclude that in denervated mucles for long period, there is decrease in the percentage of satellite cells and increase in FIF. Finally our results suggest that the period between 16th and 19th week of post denervation is the best time for reinnervation of denervated muscle.