A curva de rotação da Galáxia apresenta uma anomalia perto do raio da órbita solar R0, caracterizada pela presença de um mínimo. Existem trabalhos que, embora não façam uma afirmação categórica, interpretam o mínimo como sendo o resultado do decréscimo do efeito do disco, combinado com o aumento do efeito de um hipotético halo de matéria escura. A existência de tal interpretação reforça a importância de um estudo detalhado sobre sua natureza. No presente trabalho nós mapeamos a curva de rotação entre os raios galáticos 5 < R < 12 kpc usando diversas estrelas como traçadoras, por exemplo, Cefeidas, C-Miras, etc. Através de um método original realizamos o estudo cinemático para 322 Cefeidas. A partir desse estudo determinamos os melhores valores para os parâmetros da Galáxia, V0=202 +- 15 km/s e R0=7.5 +- 0.5 kpc. A melhor escolha possível para tais parâmetros é de fundamental importância, pois estes afetam a curva de rotação deduzida a partir de dados observacionais. Após determinarmos os valores de R0 e V0, analisamos as curvas de rotação obtidas por nós e vimos que elas apresentam um mínimo a uma distância de 1.5 +- 0.3 kpc de R0. O mínimo apresenta uma velocidade de 30 +- 10 km/s menor que a velocidade encontrada no raio galático igual a R0. Simulações computacionais mostraram que esse mínimo pode ser explicado por um déficit gaussiano na densidade superficial de matéria (gás + estrelas) do disco, com um decréscimo máximo de 30% do valor da densidade superficial total próxima a R0. Esse déficit pode ser explicado pelo efeito da co-rotação. / The Galaxy rotation curve shows an anomaly near the solar radius orbit R0, characterized by the presence of a minimum. There are works that implicitly interpret the minimum as the result of the decrease of the effect of the disk, combined with increasing of effect of a hypothetical dark matter halo. The existence of this interpretation reinforces the importance of a detailed study about its nature. In this work we obtained the rotation curve between Galactic radius, 5 < R < 12 kpc, using several stars as tracers, for instance, Cepheids, C-Miras, etc. Through a new method, we studied the kinematic of 322 Cepheids. From this study we determined the best values for the Galaxy parameters, V0=202 +- 15 km/s, and R0=7.5 +- 0.5 kpc. The best possible choice for such parameters is of fundamental importance since they affect the rotation curve inferred from observational data. After determining the values of R0, and V0, we analyzed the rotation curves obtained by us, and we saw that they have a minimum at a distance of 1.5 +- 0.3 kpc from R0. The minimum shows a velocity of 30 +- 10 km/s less than the velocity found at galactic radius R0. Computational simulations showed that this minimum can be explained by a Gaussian deficit of surface density of matter (gas + stars) of disk, with a maximum decrease of 30% of the value of surface density total arround R0. This deficit is explained by the effect of co-rotation.

Existe um conceito difundido entre professores de educação física, fisioterapeutas e ortopedistas que o joelho não deve ser demasiadamente anteriorizado em relação à ponta do pé na direção ântero-posterior durante qualquer tipo de agachamento de modo a diminuir a carga mecânica imposta ao joelho. No entanto, são escassas as evidências quantitativas que corroboram este conceito. Este trabalho tem como objetivo estimar forças e torque na articulação do joelho em indivíduos saudáveis durante o exercício de agachamento livre com peso em dois modos diferentes de execução: a) joelho não ultrapassando a linha vertical que passa pelos dedos do pé; b) joelho ultrapassando essa linha vertical. Os sujeitos realizaram o agachamento com o pé direito sobre uma plataforma de força que mensurou os torques e forças de reação do solo. O membro inferior direito dos indivíduos (pé, perna e coxa) foram filmados com cinco câmeras digitais. Visando reconstruir o movimento dos segmentos, nós utilizamos a técnica de calibração do sistema anatômico (CAST), aumentando assim, a acurácia na reconstrução da posição tridimensional dos segmentos. O centro articular do quadril foi determinado pelo método rotacional e as forças e torques articulares internos líquidos foram determinados por dinâmica inversa. Os resultados obtidos mostram que o pico da carga mecânica no joelho, quando esse passa em média 11cm da linha do pé, é cerca de 31% maior na condição em que o joelho ultrapassa a linha do pé. Esses resultados implicam que não passar o joelho da linha do pé diminui a força de compressão patelofemoral, levando assim a uma menor solicitação mecânica nesta articulação. / There is a wide spread notion among health professionals that during a squat exercise the knee should not pass forward the forefoot region in order to not overload the knee joint. However, it seems there isn’t scientific literature to support or negate this concept. The goal of this paper is to investigate the effect of different foot-knee positions on the knee joint moment and on the patelofemoral force during squat, which was performed into two different ways: a) knee do not passing the forefoot region; b) knee passing the forefoot region. The subjects performed the squat exercise with the right foot on a force plate that measured the ground reaction force and moment components. The subject’s right leg (foot, shank, and thigh) and pelvis were filmed with five digital cameras. In order to reconstruct the segments’ movement, we used the Calibrated Anatomical System Technique (CAST), improving the accuracy on three-dimensional reconstruction of segment’s position. The hip center was determined by the rotational method and the internal net forces and torques were estimated by inverse dynamics. The results showed that during the condition were knee passed the forefoot region, the knee passed 11 cm on average, what resulted in a peak of mechanical load on the knee 30% higher in relation to the do not pass condition. Based on these results it is suggested that the knee should not pass the forefoot region during squatting in order to decrease the patelofemoral force.

Através de um estudo cinemático, foi analisada a marcha de sete cães da raça Golden Retriever, fêmeas, idade entre 2 e 4 anos, peso variando de 21,5 a 28 Kg, clinicamente normais. Dados morfométricos foram coletados para descrever a população estudada. Variáveis de tempo e distâncias foram mensuradas para descrever a marcha. Movimentos de flexão e extensão foram descritos para a articulação escapuloumeral, cubital, carpal, coxofemoral, femorotibial e tarsal. A marcha foi caracterizada lateral e teve hipótese de normalidade aceita para todas as variáveis, exceto para o apoio de quadril e apoio de cúbito, considerando um grau de confiança de 95%, ou seja, nível de significância &alpha = 0,05. As variações foram atribuídas ao deslocamento do das tarjas durante o movimento e ao repetido número de avaliações. Conclusões: A análise cinemática provou ser um consistente método de avaliação do movimento durante a marcha canina e os dados obtidos podem ser utilizados na comparação em avaliações de marcha para outros estudos e base de normalidade quando comparados a evolução de tratamentos de cães com afecções musculoesqueléticas. / Through a kinematic study, was analyzed the gait of seven Golden Retrievers dogs, females, age between 2 to 4 years, weight varied of 21,5 kg to 28 Kg, clinically normal. Morphometric data were collected to describe the sample population. Temporal variable and joint movements were measured to describe the gait. Flexions and extension movements were described for the scapulohumeral, elbow, carpal, hip, femorotibial and tarsal joints. The gait was characterized lateral and had hypothesis of accepted normality for all the variables, except for the support of hip and support of elbow joints, considering a reliable degree of 95% or either, level of significance 0,05. The variations were attributed to the displacement of the targets during the movement and to trial repetition of individual dogs. Conclusions: The kinematics analysis proved to be a consistent method of evaluation of the movement during the canine gait and the database derived from the normal population in this study can be used in the comparison in evaluations of gait for other studies and baseline normality when compared in treatment of dogs with musculoskeletal diseases.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-05-25T14:58:26Z No. of bitstreams: 1 Luciane Beatriz Grohs Contani .pdf: 1089734 bytes, checksum: bd72d901079afdcce655c14f8b2549a8 (MD5) / Made available in DSpace on 2016-05-25T14:58:26Z (GMT). No. of bitstreams: 1 Luciane Beatriz Grohs Contani .pdf: 1089734 bytes, checksum: bd72d901079afdcce655c14f8b2549a8 (MD5) Previous issue date: 2014-12-11 / The aim of the present study was to analyze the Oxford Foot Model (OFM) repeatability of healthy adults during two clinical tests: the Anterior Step down Test (ASDT) and the Lateral Step down Test (LSDT). Five healthy participants (one male, four females, 10 limbs in total), with a mean age of 22.2 (±4.7) years, were assessed in four sessions of tests using an interval of one week. Two independent examiners performed two sessions of each of the tests. For each session (intra-day), nine repetitions were carried out for each clinical test (ASDT and LSDT). After an interval of three hours, the data were collected once more. The tests were conducted after an interval of a week, using the same experimental conditions. The intra and inter-session repeatability of the range of motion of the foot was determined by the standard error of measurement (SEM) of each examiner and between the examiners. Differences between the test and the retest, as well as between the examiners, were assessed using the students t-test (p<0.05). The repeatability of the data was high for the two tests conducted. The SEM results were as follows: 0.26º to 1.59º for the intra-examiner assessment (ASDT); 0.28º to 1.31º for the inter-examiner comparison (ASDT); 0.02º to 1.03º for the intra-examiner assessment (LSDT); 0.28º to 1.00º for the inter-examiner comparison (LSDT). The OFM model was shown to be reproducible in terms of assessing the range of motion during functional tests (ASDT and DAS) in healthy adults. / Os modelos convencionais usados na análise tridimensional da marcha representavam o pé como um único segmento rígido. Desta forma, são considerados, na grande maioria dos laboratórios clínicos e de pesquisa, apenas os movimentos de flexão plantar e dorsiflexão devido a sua fragilidade para mensurar outros movimentos. Por ser o pé uma estrutura complexa, é necessário tratá-lo de maneira multissegmentar. Pesquisas recentes sobre a análise de marcha, têm utilizado o Oxford Foot Model (OFM), que trata o pé de forma segmentada. Uma vez que um modelo é proposto, o estudo de sua reprodutibilidade deve ser realizado em movimentos que ainda não foram estudados, no intuito de identificar possíveis variações entre os dados obtidos, pois os mesmos podem comprometer a interpretação dos resultados e a tomada de decisão clínica. Dessa forma, este estudo tem por objetivo avaliar a reprodutibilidade do Oxford Foot Model em adultos saudáveis durante testes funcionais, notadamente Single Leg Step Down Test Anterior (SDA) e Lateral Step Down Test (SDL), que são exercícios realizados em cadeia cinética fechada. Foi analisada a cinemática do pé de cinco adultos saudáveis (com idade de 22,2 +/- 4,7 anos) durante quatro sessões para cada um dos avaliadores (dois fisioterapeutas). Os resultados apontam alta reprodutibilidade do modelo para estes testes funcionais quando se analisa o erro padrão de medida e a amplitude de movimento articular. Foram encontradas diferenças estatisticamente significativas apenas em três comparações para a atividade SDL, o que aponta a reprodutibilidade do método. Para o SDA também foram encontradas três diferenças, concentradas nas comparações de mesmo dia. O presente estudo mostrou que o número mínimo de repetições (trials) é de três a cinco, por conterem menor erro padrão de medida; para fins estatísticos aqui elencados utilizaram-se cinco repetições.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-06-19T15:01:27Z No. of bitstreams: 1 Gustavo Lacreta Toledo Colonezi.pdf: 608536 bytes, checksum: 6f8b788f6abee5387f62055ac9f34005 (MD5) / Made available in DSpace on 2018-06-19T15:01:27Z (GMT). No. of bitstreams: 1 Gustavo Lacreta Toledo Colonezi.pdf: 608536 bytes, checksum: 6f8b788f6abee5387f62055ac9f34005 (MD5) Previous issue date: 2015-12-15 / INTRODUCTION: Abnormal trunk movements in the sagittal plane during weight-bearing activities can have a direct effect on the joints of the lower limbs. It is known that a greater range of trunk flexion leads to less patellofemoral stress. Assessments of the kinematics of patients who suffer from patellofemoral pain (PFP) during several activities can be found in the literature. However, none of these studies have addressed the effects of trunk flexion during the single leg hop test (SLHT). OBJECTIVE: Therefore, the aim of the present study was to assess the relation of trunk flexion on pain (NPRS 0-10), functional performance (SLHT distance) and the angular kinematics of the lower limbs of women with PFP during the propulsion phase of the SLHT. METHODS: Thirty-four sedentary women, with a mean age of 25.59 (18 - 35 years), were assessed retrospectively in terms of pain, functional performance and three-dimensional kinematics during the propulsion phase of the SLHT. The women were then divided into two groups based on the maximum angular value of the trunk: less trunk flexion (LFT group, n=17) and greater trunk flexion (GFT group, n=17). RESULTS: Differences were found between the groups for pain (P=0.04; Effect Size (ES) =0.70 ; mean difference = 0.88; Confidence Interval (CI) = 95%: 0.01 – 1,75), LFT group presented less pain than GFT group. Therefore women in the GFT group exhibited better functional performance funcional (P=0.01; ES=1.17 mean difference: 16.29cm; 95% CI: 25.95 - 6.62) than those in the LFT group. The GFT group also performed higher values of ipsilateral trunk lean (mean difference: 2.5°; 95% CI: 0.9 a 4.1°), pelvic anteversion (mean difference: 5.8°; 95% CI: 1.7 a 9.8°), hip flexion (mean difference: 8.2°; 95% CI: 2.1 a 14.4°) and ankle dorsiflexion (mean difference: 3.7°; 95% CI: 0.3 a 7.1°) than the LFT group. CONCLUSION: Increases in the sagittal plane trunk flexion shows relation to the functional performance and angular kinematics of proximal segments during the propulsion phase of the SLHT. / INTRODUÇÃO: Alterações dos movimentos do tronco no plano sagital durante atividades com descarga de peso podem ter efeito direto sobre as articulações dos membros inferiores. Sabe-se que maior amplitude de flexão do tronco diminui o estresse femoropatelar. Avaliações cinemática de pacientes que sofrem com dor femoropatelar (DPF) durante várias atividades podem ser encontrados na literatura. No entanto, nenhum estudo abordou a influência da flexão do tronco durante o single leg hop test (SLHT). OBJETIVO: Portanto, o objetivo do presente estudo foi avaliar a relação da flexão do tronco sobre a dor (NPRS 0-10), o desempenho funcional (distancia do SLHT) e da cinemática angular dos membros inferiores em mulheres com DPF durante a fase de propulsão dos SLHT. MÉTODOS: Trinta e quatro mulheres sedentárias, com idade média de 25,59 (18 - 35 anos), foram avaliadas em termos de dor, desempenho funcional e cinemática tridimensional durante a fase de propulsão do SLHT. As voluntárias foram divididas em dois grupos com base no valor angular máximo de flexão de tronco: menor flexão de tronco (MEFT grupo, n = 17), e com maior flexão do tronco (MAFT grupo, n = 17). RESULTADOS: Diferenças foram encontradas entre os grupos para a dor (P=0.04; Effect Size (ES) =0.70 ; diferença média = 0.88; Intervalo de Confiança (IC) = 95%: 0.01 – 1,75), sendo que, o grupo MEFT apresentou menos dor em relação ao grupo MAFT. Entretanto as voluntárias do grupo MAFT exibiram melhor desempenho funcional (P=0.01; ES=1.17 diferença média: 16.29cm; 95% IC: 25.95 - 6.62) do que aquelas do grupo MEFT. O grupo MAFT também apresentou maiores valores de inclinação ipsilateral de tronco (diferença média: 2.5°; 95% IC: 0.9 a 4.1°), anteversão pélvica (diferença média: 5.8°; 95% IC: 1.7 a 9.8°), flexão de quadril (diferença média: 8.2°; 95% IC: 2.1 a 14.4°) e dorsiflexão do tornozelo (diferença média: 3.7°; 95% IC: 0.3 a 7.1°). CONCLUSÃO: O aumento da flexão do tronco no plano sagital mostra relação com melhor desempenho funcional e com a cinemática angular de segmentos proximais durante a fase de propulsão do SLHT.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-07-17T20:24:08Z No. of bitstreams: 1 Aline de Almeida Novello.pdf: 1138078 bytes, checksum: 601d6ef4a7fc406204ec932dce901793 (MD5) / Made available in DSpace on 2018-07-17T20:24:08Z (GMT). No. of bitstreams: 1 Aline de Almeida Novello.pdf: 1138078 bytes, checksum: 601d6ef4a7fc406204ec932dce901793 (MD5) Previous issue date: 2016-12-13 / Evidences found in the literature are inconsistent and there is no consensus about the kinematic differences performed by women with patellofemoral pain (PFP) during stair descent, and there are no studies that have evaluated the tridimensional kinematics of the trunk, pelvis, hip, knee and ankle using a multisegmental model of the foot, simultaneously during this task in patients with PFP and evaluated separately the sub phases of stair descent. Therefore, the aim of this study was to compare the tridimensional kinematics of the trunk, pelvis and lower limbs in different sub phases of stair descent and identify the discriminatory capability of the kinematic variables among PFP and healthy women during this task. In this cross-sectional study, thirty-four women with PFP (PFP group) and thirty-four painless women (control group) between 18 and 35 years-old underwent kinematic evaluation during the stair descent. It was observed that kinematic differences between groups occurred only in the first double support phase of the stair descent and the variables of internal rotation of the hindfoot in relation to the tibia in the initial contact, the contralateral pelvic drop in the load-response, external rotation range of motion of the hindfoot in relation to the tibia and dorsiflexion of the forefoot in relation to the hindfoot were the variables that presented the best capacity to discriminate women with and without PFP. Therefore, our results provided a better understanding of the trunk, pelvis and lower limbs kinematics in different subphases of the support phase of stair descent in women with PFP. / As evidências encontradas na literatura são inconsistentes e não há consenso sobre as alterações cinemáticas em mulheres com dor femoropatelar (DFP) durante a descida de escadas. Além disso, não há estudos que tenham avaliado a cinemática tridimensional do tronco, pelve, quadril, joelho e tornozelo, utilizando um modelo multisegmentar do pé, simultaneamente durante esta tarefa em pacientes com DFP e que tenha avaliado separadamente as subfases da descida de escadas. Portanto, os objetivos deste estudo foram comparar a cinemática tridimensional do tronco, pelve, e membros inferiores em diferentes subfases da descida de escadas e identificar a capacidade discriminatória das variáveis cinemáticas entre mulheres com DFP e saudáveis nesta tarefa. Neste estudo transversal trinta e quatro mulheres com DFP (grupo DFP) e trinta e quatro mulheres sem dor (grupo controle) entre 18 e 35 anos foram submetidas à avaliação cinemática durante a descida de escadas. Foi observado que diferenças cinemáticas entre os grupos ocorreram somente na fase de primeiro duplo apoio da descida de escadas, sendo que as variáveis de rotação interna do retropé em relação à tíbia no contato inicial, a queda contralateral da pelve na resposta à carga, a amplitude de rotação externa do retropé em relação à tíbia e de dorsiflexão do antepé em relação ao retropé foram as variáveis que apresentaram melhor capacidade de discriminar mulheres com e sem DFP. Sendo assim, nossos resultados proporcionaram maior entendimento da cinemática do tronco, pelve e membros inferiores em diferentes subfases do apoio na descida de escadas em mulheres com DFP.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2018-07-17T20:38:16Z No. of bitstreams: 1 André Nogueira Ferraz de Carvalho e Silva.pdf: 1053634 bytes, checksum: 032d316a96c55892bc3977f4efa8f29c (MD5) / Made available in DSpace on 2018-07-17T20:38:16Z (GMT). No. of bitstreams: 1 André Nogueira Ferraz de Carvalho e Silva.pdf: 1053634 bytes, checksum: 032d316a96c55892bc3977f4efa8f29c (MD5) Previous issue date: 2016-12-15 / Background: Patellofemoral pain (PFP) is described as anterior knee pain, aggravated by negotiating stairs, squats, running and prolonged sitting. Proximal changes such as trunk, pelvic drop, hip adduction and medial rotation may cause pain. Recently, new studies have indicated that distal changes influence PFP. Objective: Analyze trunk, lower limbs, rearfoot and forefoot kinematics during the beginning of the movement, 15º, 30º and 45º of knee flexion and their discriminatory capacity between patients with PFP and healthy on the lateral step down. Methods: Thirty-four healthy sedentary women and thirty-four women with PFP were evaluated in three-dimensional kinematics during Lateral Step Down at the beginning of the movement, 15º, 30º and 45º of knee flexion. Analyzes were performed between the groups and the Receiver Operational Characteristic Curves (ROC) were applied to determine the discriminatory capacity between them. Results: Differences were found between the groups being more evident at 30º and 45º of knee flexion in the PFP group in the trunk and lower limbs. Conclusion: The main kinematic changes occur at 30º and 45º of knee flexion. At 30º of knee flexion, the main variables to discriminate women with PFP from the healthy ones are: pelvic drop, hip adduction, rearfoot eversion in relation to the ground and forefoot pronation in relation to the rearfoot, already at 45º, a main variable is the eversion of the rearfoot in relation to the ground. / Introdução: A dor femoropatelar (DFP) é descrita como uma dor anterior no joelho, agravada em subida e descida de escadas, agachamentos, corridas e tempo prolongado na posição sentado. Alterações proximais como de tronco, quadril, queda da pelve, adução e rotação medial do fêmur podem causar a dor. Recentemente, novos estudos apontam que alterações distais influenciam na DFP. Objetivo: Analisar a cinemática do tronco, membros inferiores, retropé e antepé durante o início do movimento, 15º, 30º e 45º de flexão do joelho e sua capacidade discriminatória entre pacientes com DFP e saudáveis no lateral step down. Métodos: Trinta e quatro mulheres sedentárias saudáveis e trinta e quatro mulheres com a DFP, foram avaliadas na cinemática tridimensional durante Lateral Step Down no início do movimento, 15º, 30º e 45º de flexão do joelho. Foram feitas análises entre os grupos e aplicado as Curvas de Características de Operação do Receptor (ROC) para determinar a capacidade discriminatória entre eles. Resultados: Diferenças foram encontradas entre os grupos sendo mais evidentes a 30º e 45º de flexão do joelho no grupo DFP no tronco e membros inferiores. Conclusão: As principais alterações cinemáticas acontecem a 30º e 45º de flexão do joelho. A 30º de flexão do joelho, as principais variáveis para discriminar mulheres com a DFP das saudáveis são: a queda da pelve, adução do quadril, eversão do retropé em relação ao solo e pronação do antepé em relação ao retropé, já a 45º, a principal variável é a eversão do retropé em relação ao solo.

Les patients hémiparétiques présentent des troubles de la marche couramment évalués, lors d’une marche stabilisée en ligne droite, par des tests cliniques chronométriques et parfois par une analyse quantifiée de la marche explorant les paramètres biomécaniques de celle-ci. L’analyse de tâches de navigation dans l’environnement, impliquant des contraintes rencontrées au quotidien, apparait pertinente parallèlement à l’analyse de la marche stabilisée en ligne droite. Le test du Timed Up and Go (TUG) comprend des tâches de marche orientée vers une cible et de demi-tour, ce qui correspond à un grand nombre de déplacements effectués dans la vie quotidienne. Cependant la performance chronométrique obtenue à l’issue de ce test ne permet pas la compréhension des mécanismes à l’origine de cette performance. L’objectif principal de cette thèse est de caractériser les déplacements locomoteurs des patients hémiparétiques au cours de tâches de navigation telles que celles impliquées dans le TUG. Pour cela nous proposons une analyse biomécanique de leurs déplacements au cours des 3 phases de navigation du TUG (marche orientée vers l’obstacle, demi-tour et marche orientée vers le siège). Cette analyse concerne l’étude de la cinématique, de la stabilité et des trajectoires locomotrices de ces patients et de sujets sains. L’originalité de ce travail repose sur la caractérisation biomécanique de l’organisation des patients hémiparétiques lors de tâches de navigation, au moyen de paramètres innovants. La diminution de la performance chronométrique observée chez les patients hémiparétiques,comparativement aux sujets sains, s’explique tout d’abord par une diminution de la majorité des paramètres spatio-temporels et de la cinématique articulaire lors des 3 phases de navigation des patients. De plus, les résultats montrent que les phases de marche orientée sont contrôlées par les mêmes paramètres pour les patients hémiparétiques et les sujets sains, mais avec une pondération différente et, que la phase du demi-tour est contrôlée par des paramètres spécifiques différents. Les résultats mettent également en évidence des différences organisationnelles entre les patients hémiparétiques et les sujets sains, à savoir un défaut de stabilité, un ralentissement lors du demitour et une déviation de la trajectoire locomotrice pour les patients. Ces résultats suggèrent que les patients hémiparétiques mettent en place une stratégie consistant en un compromis entre la stabilité, la trajectoire et la performance pour une réalisation optimale des tâches de navigation telles que celles réalisées lors du TUG. Des répercussions sur la prise en charge clinique des patients hémiparétiques peuvent être envisagées à l’issue de ce travail. / The gait characteristics of patients with hemiparesis are usually assessed during stable, straightline gait. Clinical tests are mostly based on timed performance, although biomechanical gait analysis may be carried out. The analysis of navigational tasks that involve constraints encountered in daily life is necessary to increase understanding of gait deficits. The Timed Up and Go test (TUG) includes oriented gait towards a target, and turning tasks, typical of real-life gait. However, the simple analysis of performance time does not provide sufficient information regarding actual performance of the tasks. The main aim of this thesis was to characterize the locomotor displacements of hemiparetic patients during navigational tasks, such as those involved in the TUG. To this end, we carried out a biomechanical analysis of gait during the three navigational tasks of the TUG (oriented gait to the target, turning and oriented gait to the seat). We analysed the kinematics, stability and locomotor trajectories of patients and healthy subjects. This work is original because it provides a biomechanical characterization of the organization of gait in patients with hemiparesis during navigational tasks, using innovative parameters. The longer performance time in hemiparetic patients, compared with healthy subjects, was related to a decrease in the majority of spatio-temporal and joint kinematic parameters. Moreover, the results showed that oriented gait tasks were controlled by the same parameters in hemiparetic patients and healthy subjects, but in different proportions. In contrast, the turning task was controlled by different, specific parameters. Organizational differences between hemiparetic patients and healthy subjects were also highlighted, namely a lack of stability, slowing during the turn and deviation from the trajectory by the patients. These results suggest that hemiparetic patients use a strategy which is a compromise between stability, trajectory and performance for the optimal achievement of navigational tasks, such as these involved in the TUG. The implications of this work for the clinical management of hemiparetic patients are explained.

Le syndrome de parésie spastique consécutif à un accident vasculaire cérébral (AVC) comprend plusieurs composantes dont la rétraction musculaire, la parésie sensible à l’étirement et l’hyperactivité musculaire, trois symptômes concourant à une altération de la fonction motrice du membre supérieur dans l’hémiparésie. Les progrès d’un patient atteint par ce syndrome peuvent reposer sur deux types de plasticité cérébrale : post-lésionnelle et liée à l’activité. Les maîtres-mots pour optimiser une récupération motrice par la plasticité liée à l’activité sont : intensité, répétition, effort, attention portée au mouvement, tâche dirigée vers un but et mouvement actif. Au regard des différentes techniques de rééducation, la thérapie utilisant un dispositif robotisé répond à ces principes stimulateurs de la plasticité cérébrale liée à l’activité. Cependant les modalités exactes de l’intervention robotisée et sa durée souhaitable n’ont pas été clarifiées.Une première étude rétrospective a montré que les bénéfices cliniques et cinématiques associés à l’utilisation combinée de l’ergothérapie conventionnelle et de la robot-thérapie sur au moins trois mois suggèrent l’intérêt d’une durée de traitement longue chez des patients aux limitations modérées en phase tardive de la période subaiguë. Une deuxième étude rétrospective suggère qu’à quatre ans, l’évolution lente de la fonction motrice pour ces mêmes patients semble fonction de la sévérité initiale, où finalement les moins bons régressent et les meilleurs s’améliorent un peu. Enfin, une étude prospective randomisée contrôlée en phase subaiguë a démontré que l’entraînement de mouvements sur robot sans assistance améliore l’amplitude active d’extension du coude plus que le même entraînement avec assistance au besoin, qui pourtant a permis au patient d’effectuer environ un tiers de mouvements en plus par séance. Aussi, le facteur difficulté de l’effort prévaudrait sur celui du nombre de répétitions pour stimuler la plasticité cérébrale. Ce dernier principe ne s’exprime cependant que sur le mouvement élémentaire qui est directement entraîné par le robot, en l’occurrence l’extension du coude, tandis que d’autres mouvements fondamentaux dans l’utilisation du bras humain, par exemple la flexion de l’épaule en charge, l’extension du poignet et la préhension digitale, ne sont pas exercés avec la plupart des versions actuelles des robots d’assistance à la rééducation. L’autre limite majeure de la thérapie assistée par un dispositif robotisé est qu’elle ignore la maladie musculaire présentée par les patients (rétractions), ne s’adressant qu’à la composante neurologique de la parésie spastique (parésie de l’agoniste et cocontraction de l’antagoniste). C’est ainsi que malgré le grand nombre de répétitions de mouvements qu’elle permet, nous n’avons pas constaté que la thérapie assistée par un robot se montrait plus efficace que la thérapie conventionnelle seule sur la progression de la fonction globale du membre supérieur en phase subaiguë après un AVC.Les données issues de ce travail devraient permettre aux thérapeutes ayant accès à des dispositifs robotisés d’aide à la rééducation du membre supérieur d’affiner les modalités et la durée de leur prise en charge. L’association de la thérapie assistée par robots à d’autres thérapies pourrait permettre d’optimiser la réduction des troubles moteurs dans l’hémiparésie après un AVC. / Following stroke, the syndrome of deforming spastic paresis includes several components in which three main symptoms, soft tissue contracture, stretch-sensitive paresis and spastic muscle overactivity, impede motor function. Patient progress may utilize two types of brain plasticity: lesion-induced and behavior-induced. The key notions to optimize motor recovery through behavior-induced plasticity are: repetition, effort, attention to movement, goal-directed task and active movement. Robot-assisted therapy fulfills all these conditions. However, the exact modalities of use and optimal duration are yet to be defined.From a first retrospective study, the magnitude of the clinical and kinematic benefits associated with the combined use of robot-assisted and conventional occupational therapies during three months suggest the value of a long duration treatment in the late subacute phase for moderately impaired hemiparetic patients. A second retrospective study observed the four-year long-term evolution of motor function for these patients, which appears to be related to the baseline severity, in which the more severely affected deteriorate and the less severe patients improve a little. Finally, a prospective randomized controlled study demonstrated that non-assisted movement training was associated with greater active elbow extension improvement than training with the assist-as-needed modality even though the latter offered the patient 33% movements more in each session. Therefore, the difficulty of effort appears to be a more effective factor of brain plasticity than the number of movement repetitions. This principle has however been demonstrated only for the primary movement directly trained by the robot, that is, elbow extension. The other movements that are essential in human upper limb use, such as shoulder flexion, wrist extension, gross and fine digit prehension, are not trained with the most current versions of robots used in upper limb rehabilitation. In addition, another important limitation of robot-assisted therapy is that it ignores the muscle disorder (antagonist shortening) of spastic paresis by focusing only on the neural disorder component (paresis in agonists and cocontraction in antagonists). Despite the high number of movement repetitions in robot-assisted therapy, our prospective study has not been able to show superiority of robot-assisted therapy over conventional occupational therapy in improving overall upper limb motor function in the subacute phase after stroke.The findings of this work should help therapists with access to robotic devices to refine the modalities and duration of their use in patient care. Combining robot-assisted therapy with other therapies might optimize the reduction of motor disorder in hemiparesis following stroke.

Idiopathic congenital clubfoot can be treated either operatively (comprehensive surgical release (CSR)) or conservatively (ponseti technique (PCT)). This thesis compared the mid-term outcomes after CSR and PCT treatments to a typically developing sample. A Dynamical Systems Analysis (DSA) approach and a multi-segment foot model were used to examine group differences in multi-segment foot and lower extremity kinematics, kinetics, coordination and coordination variability during walking. Ten children with clubfoot treated with PCT and seven children with clubfoot treated with CSR were evaluated retrospectively and compared to ten typically developing children. Multi-segment foot and lower extremity kinematic (240 Hz) and kinetic (1080 Hz) data were collected while participants walked barefoot at a fixed walking velocity (1.0 m/s-1 ±5%). Sagittal plane metatarsophalangeal (MTP) and three-dimensional (3D) forefoot-rearfoot, ankle, knee and hip joint range of motion (ROM) during stance and 3D ankle, knee and hip peak joint moments during push-off were calculated. A modified vector coding technique was used to quantify the multi-segment foot and lower extremity coordination and coordination variability throughout stance for forefoot-rearfoot inversion/eversion (Ff-Rf), rearfoot inversion/eversion–tibial internal/external rotation (Rf-Tib) and femur-tibia internal/external rotation (Fem-Tib) couples. Reduced MTP and forefoot-rearfoot ROM was observed in the CSR group while the PCT group demonstrated values comparable to CTR. Sagittal plane ankle ROM was similar between groups however, the CSR group demonstrated reduced frontal plane ROM compared to PCT. Peak ankle plantar flexion moment was reduced in the last 50% of stance in the clubfoot groups. The CSR group demonstrated greater knee and hip moments compared to CTR and PCT. The PCT group demonstrated lessor peak ankle eversion, knee external rotation and knee valgus moments compared to CTR. No significant differences were observed in Ff-Rf, Rf-Tib and Fem-Tib coordination and coordination variability throughout stance between the groups. PCT and CSR gait was characterized by restricted multi-segment foot motion and abnormal lower extremity joint moments; suggesting mild residual deformity. Despite residual deformity, the coordination and coordination variability results indicate that the PCT and CSR groups are not functionally limited and demonstrate similar multi-segment foot and lower extremity movement patterns as CTR.