Introdução. Os pacientes com DPOC apresentam capacidade de exercício reduzida e limitação funcional para realização de suas atividades diárias, impactando a qualidade de vida desses indivíduos. Além disso, foi demonstrado para esses indivíduos um maior risco de queda em comparação a indivíduos saudáveis da mesma idade. Contudo, não se sabe o papel da intolerância ao exercício em variáveis relacionadas a locomoção dos pacientes com DPOC como o custo de transporte (C), a velocidade autosselecionada (VAS) e a estabilidade dinâmica, que podem auxiliar na dimensão da influência dessa intolerância na vida diária desses indivíduos. Objetivo. O presente estudo se propôs a investigar o comportamento do C, da eficiência ventilatória, do conforto ventilatório e da estabilidade dinâmica em diferentes velocidades de caminhada de indivíduos com DPOC e comparar com indivíduos sem a doença, além de verificar a possível correspondência entre a VAS e a velocidade ótima. Materiais e Métodos. Onze participantes com DPOC fizeram parte desse estudo e foram comparados com onze controles pareados por sexo e idade. Eles foram primeiramente submetidos a um teste de exercício cardiopulmonar e, em um segundo momento, a uma avaliação do C. No protocolo submáximo, os participantes caminharam em cinco velocidades diferentes, sendo uma a VAS e outras quatro ±20% e ±40% da VAS. Além disso, os participantes foram avaliados em uma velocidade pré-determinada igual a todos (isovelocidade). Para todas as velocidades do protocolo os participantes caminharam durante cinco minutos. A partir dos valores de consumo de oxigênio (VO2) obtidos, foram calculados os valores de C. Simultaneamente, foram realizados registro de vídeos dos participantes para posterior análise cinemática da marcha. Foram calculados a frequência de passada (FP), o comprimento de passada (CP) e o coeficiente de variação (CoV) referente a FP, como medida da estabilidade dinâmica. Resultados. Não houve diferença do C dos pacientes com DPOC em relação aos controles, nem mesmo quando caminhavam em isovelocidade (p=0,623). Em todas as velocidades, os pacientes demonstraram menor eficiência ventilatória. A VAS dos pacientes foi menor, no entanto observou-se menor valor de C nas velocidades mais altas de caminhada. Apesar de os indivíduos com DPOC apresentarem menor FP e CP, a estabilidade dinâmica não demonstrou-se prejudicada na amostra estudada. Conclusão. Pacientes com DPOC caminham em velocidades reduzidas, em relação aos controles, especialmente devido à dispneia acompanhada de uma menor eficiência ventilatória. Embora o C seja semelhante ao de indivíduos saudáveis, os participantes com DPOC apresentaram o índice de reabilitação inferior, sugerindo, portanto, que o mecanismo pendular não esteja otimizado na VAS. Além de não encontrar diferenças na economia de caminhada, foram observadas alterações mínimas na estabilidade dinâmica da marcha destes indivíduos. Terapias que tratem do conforto ventilatório são potenciais ferramentas para a melhora da locomoção de pacientes com DPOC. / Background. Subjects with COPD present reduced exercise capacity and functional limitation to perform daily activities, which affects their quality of life. Furthermore, it is known that this population has increased risk of falls when compared to health subjects. However, it is still unknown the role of exercise intolerance on important variables to assess locomotion, as the cost of transport (C), the self-selected speed (VAS) and the dynamic stability, which might be able to help to dimension the exercise intolerance on their daily life. Objective. To investigate the behaviour of C ventilatory efficiency, ventilatory comfort and dynamic stability at different walking speeds in COPD subjects and compare them to healthy controls, as well as to verify the possible correspondence of VAS and optimal speed. Methods and Materials. 11 patients with COPD participated in this study and were matched with 11 control subjects in terms of gender and age. They underwent a cardiopulmonary exercise test and an evaluation of C. In this last evaluation, participants walked at five different walking speeds, among them VAS and the others ±20% and ±40% of the VAS. There was also a sixth predetermined walking speed (isovelocity). The participants walked during five minutes in each speed. The C values were calculated from the oxygen consumption (VO2) values. Simultaneously, the subjects were filmed for later analysis of gait kinematics. The stride frequency (FP), stride length (CP) and the coefficient of variation (CoV) from FP as a measure of dynamic stability, were calculated. Results. There was no significant difference between the C of participants with COPD and control subjects, not even when walking at isovelocity (p=0,623). For all speeds investigated, the ventilatory efficiency of COPD subjects was impaired when compared to healthy individuals. The participants in COPD group walked at a slower VAS, but the lower value of C was found during faster walking speeds. Even though the COPD group had less FP and shorter strides, their dynamic stability showed minimal impairment. Conclusion. The patients with COPD walked at a reduced walking speed when compared to control subjects, specially caused by dyspnea and a lower ventilatory efficiency. In spite of a similar C between groups, the COPD subjects presented an inferior rehabilitation index, therefore suggesting that their pendulum-like mechanism is not optimal at VAS. Furthermore, besides a walking economy with no differences between groups, minimal impairments were found for dynamic stability in COPD group. Therapies that treat ventilatory comfort are a potential tool to improve locomotion of COPD subjects.

Thesis. 1977. B.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / B.S.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographies. / by Erik Karl Antonsson. / Ph.D.

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 203-204. / by Frank C. Conati. / M.S.

O transporte de cargas pode causar lesões e dores na coluna. Entre as mães é frequente a existência de lombalgia, sendo o carregamento de bebês no colo uma tarefa comum e relevante. Apesar disso não há trabalhos reportando os efeitos biomecânicos do transporte de bebês. Objetivo: O objetivo deste estudo foi investigar o impacto do transporte de bebês sobre as curvaturas da coluna vertebral e sobre o deslocamento do centro de gravidade (CG) do corpo de mães. Secundariamente, foi verificada a possibilidade dos efeitos serem diferentes dos decorrentes do transporte de cargas inanimadas, bem como do transporte por mulheres que nunca tiveram filhos. Método: 20 mães com seus filhos de aproximadamente 10 kg (grupo Mães) e 44 mulheres que nunca tiveram filhos (grupo Não-Mães) participaram deste estudo. Todas as participantes foram avaliadas usando um sistema de captura de movimento em 3D, durante a realização das seguintes tarefas: (1) caminhar em linha reta em uma superfície plana com velocidade confortável auto-selecionada por cerca de 7 m e (2) manter-se na postura ereta quieta por trinta segundos, em cima de uma plataforma de força. Para ambas as tarefas, havia três condições para o grupo Mães: (A) carregando nada (sem carga), (B) carregando seu bebê no colo (bebê), e (C) carregando um boneco de peso ajustado ao peso do bebê e com 50 cm de comprimento (boneco). O grupo Não-mães realizou apenas as condições sem carga e boneco, com peso fixo de 10kg. O bebê e o boneco foram carregados sempre à frente do corpo, com os dois braços. Resultados: Os dois grupos apresentaram-se semelhantes com relação à idade das participantes (p<0,05). O transporte da carga influenciou apenas os ângulos do plano sagital para o grupo Mães (p<0,001): inclinação pélvica (sem carga= 12°; boneco= 10°; bebê= 10°), cifose torácica (sem carga= 25°; boneco= 29°; bebê= 30°), lordose lombar (sem carga= 17°; boneco=27°; bebê= 25°) e extensão do tronco (sem carga= 6°; boneco= -4°; bebê= -2°). Da mesma forma, alterações destas curvaturas foram observadas no grupo Não-Mães (p<0,001): inclinação pélvica (sem carga= 14°; boneco= 12°), cifose torácica (sem carga= 25°; boneco= 28°), lordose lombar (sem carga= 19°; boneco= 24°) e extensão do tronco (sem carga= 5°; boneco= -2°). As condições bebê e boneco imprimiram alterações diferentes na cifose torácica, na lordose lombar e na extensão do tronco de mães (p<0,05). Diferenças entre os ajustes posturais realizados pelas mulheres dos dois grupos só foram notáveis nos ângulos médios de lordose lombar e extensão do tronco (p<0,001). O efeito do peso extra no deslocamento do CG para cima foi similar entre as condições de carga realizadas pelo grupo Mães (sem carga= -4 cm; boneco= 2 cm; bebê= 2 cm) e pelo grupo Não-mães (sem carga= -4 cm; boneco= 1 cm), sem diferença entre os grupos (p>0.05). Conclusão: carregar bebês no colo produz alterações significantes nas curvaturas da coluna vertebral de mães, principalmente na região lombar da coluna. Há diferenças significativas do transporte de carga inanimada e dos ajustes posturais realizados por mulheres que nunca tiveram filhos / Background: Load carriage may cause spinal pain and biomechanics lumbar spine alteration. Among women, carrying babies is a frequent and relevant spinal load but there are no data regarding its biomechanical effect. Purpouse: This study aims to investigate the impact of transporting babies in spinal curvature and in the displacement of center of gravity (COG) on the body of mothers. Secondly, this effect was compared to those effects arising from inanimate cargo transportation, and transportation for women who never had children. Method: Twenty consecutive mothers with babies with approximately 10kg (M-group) and 44 women never pregnant (NM-group) were included in the study. All of them were evaluated using 3D movement analysis system and data were calculated as 2D projection angles in the following conditions: no load (NL); carrying a dummy (D) with similar weight of their respective babies for M-group and with 10kg for NM-group and carrying baby (B) just for mothers. Babies and dummies were carried at the front of the trunk with both arms and tasks performed were: walking 10 trials straight on a flat floor at a comfortable speed, one trial standing still and upright for 30 seconds. Results: The two groups had comparable mean of age (p<0,05). Load affected only the sagital plane angles for the M-group (p<0,001): pelvic inclination (NL= 12°; D= 10°; B= 10°), thoracic kyphosis (NL= 25°; D= 29°; B= 30°), lumbar lordosis (NL= 17°; D= 27°; B= 25°) and trunk extension (NL= 6°; D= -4°; B= -2°). Likewise, alterations in these curvatures was observed in NM-group (p<0,001): pelvic inclination (NL= 14°; D= 12°), thoracic kyphosis (NL= 25°, D= 28°), lumbar lordosis (NL= 19°, D= 24°) and trunk extension (NL= 5°; D= -2). The load conditions printed different alterations in thoracic kyphosis, lumbar lordosis and trunk extension for the M-group (p<0,05). Differences between the postural adjustments made by women in both groups were only notable angles average lumbar lordosis and trunk extension (p <0.001). The effect of extra weight in the upward displacement of the CG was similar between the loading conditions conducted by the group Mothers (no load = -4 cm = 2 cm doll, baby = 2 cm) and the group non-mothers (no load = -4 cm; dummy = 1 cm), with no difference between groups (p> 0.05). Conclusion: In conclusion, carrying babies produces significant alterations on the spinal curvatures of mothers, mainly at the lumbar region. There are significant differences of the inanimate load transport and postural adjustments made by women who never had children

A caminhada e a corrida são formas de exercício físico que promovem mudanças no estilo de vida, mas, existem muitas controvérsias dos possíveis benefícios e riscos a respeito da caminhada ou corrida quando realizada em diferentes inclinações. O presente estudo teve como objetivo determinar o limiar anaeróbio bem como avaliar e comparar as respostas fisiológicas durante exercícios contínuos (45 minutos) com intensidade correspondente ao limiar anaeróbio executados na esteira rolante nas condições de inclinação positiva (+10%), plano (0%) e inclinação negativa (-10%). Participaram deste estudo 9 mulheres com idades entre 21 e 31 anos, fisicamente ativas. Primeiramente elas realizaram testes crescentes para determinação da intensidade correspondente ao limiar anaeróbio em cada inclinação. Após essa determinação foram realizados os protocolos contínuos na intensidade correspondente ao limiar anaeróbio por 45 minutos. Os resultados encontrados mostraram que o valor médio (\'+ OU -\' desviopadrão) da velocidade correspondente ao limiar anaeróbio no plano foi de 6,56 \'+ OU -\' 0,53 Km/h, na inclinação positiva foi de 5,44 \'+ OU -\' 0,53 Km/h (com redução percentual de 17,07% em relação ao plano) e na inclinação negativa foi de 7,22 \'+ OU -\' 0,67 Km/h (com elevação percentual de 9,14% em relação ao plano). Nos protocolos contínuos foi observado que os valores das variáveis ventilatórias apresentaram-se mais elevados para o protocolo com inclinação positiva, já a freqüência cardíaca apenas apresentou diferença até o 15º minuto do exercício entre os protocolos com inclinação positiva e o protocolo com inclinação negativa. Mas apesar disso, as voluntárias não relataram dificuldade do gesto motor na realização dos exercícios. Conclui-se que mesmo com a tentativa de se trabalhar na velocidade ideal para cada condição imposta, as respostas cardiovasculares e metabólicas são diferentes, ) principalmente entre o protocolo com inclinação positiva e o protocolo com inclinação negativa. O presente trabalho mostrou pontos importantes que devem ser levados em consideração, quanto à escolha do protocolo aplicado nos treinamentos físicos em indivíduos com diferentes condições físicas quando se propõem diferentes velocidades de corrida e inclinações da esteira. / Walking and running are forms of exercise that promote changes in lifestyle, but there are many controversies about the possible benefits and risks regarding the walking or running when performed at different slopes. This study aimed to determine the anaerobic threshold and to evaluate and compare the physiological responses during continuous exercise (45 minutes) with intensity corresponding to anaerobic threshold run on the treadmill in terms of positive slope (+10%), level (0%) and negative slope (-10%). The study included 9 women aged between 21 and 31 years old, physically active. First they performed increasing intensity tests to determine the intensity corresponding to anaerobic threshold on each slope. After determining these parameters the continuous protocols were performed in intensity corresponding to anaerobic threshold for 45 minutes. The results showed that the speed average (\'+ OU -\' standard deviation) at level the anaerobic threshold was 6.56 \'+ OU -\' 0.53 km/h, atthe positive slope was 5.44 \'+ OU -\' 0.53 km/h (with a percentage reduction of 17.07% over the level) and the negative slope was 7.22 \'+ OU -\' 0.67 km/h (with high percentage of 9.14% over the level). In continuous protocols was observed that the values of ventilatory variables were more elevated for the protocol with positive slope and the heart rate showed only significant difference until the 15th minute of exercise between protocols with positive slope and with negative slope. But despite this, the volunteers reported no difficulty in motor gesture in exercises. It was conclude that even with the attempt to run at ideal speed for each condition the cardiovascular and metabolic responses are different, especially between the protocol with positive slope and with negative slope. This study showed important points that should be taken into account in the choice of protocol used in physical training in individuals with different physical conditions when they propose different running speeds and inclinations of the treadmill.

Although most batoids (skates and rays) are benthic, only the skates (Rajidae) have been described as performing benthic locomotion, termed 'punting'. While keeping the rest of the body motionless, the skate's specialized pelvic fins are planted into the substrate and then retracted caudally, which thrusts the body forward. This may be advantageous for locating and feeding on prey, avoiding predators, and reducing energetic costs. By integrating kinematic, musculoskeletal, material properties, and compositional analyses across a range of morphologically and phylogenetically diverse batoids, this dissertation (i) demonstrates that punting is not confined to the skates, and (ii) provides reliable anatomical and mechanical predictors of punting ability. Batoids in this study performed true punting (employing only pelvic fins), or augmented punting (employing pectoral and pelvic fins). Despite the additional thrust from the pectoral fins, augmented punters failed to exceed the punting c apabilities of the true punters. True punters' pelvic fins had greater surface area and more specialized and robust musculature compared to the augmented punters' fins. The flexural stiffness of the main skeletal element used in punting, the propterygium, correlated with punting ability (3.37 x 10-5 - 1.80 x 10-4 Nm2). Variation was due to differences in mineral content (24.4-48-9% dry mass), and thus, material stiffness (140-2533 MPa), and second moment of area. The propterygium's radius-to-thickness ratio (mean = 5.52 +-0.441 SE) indicated that the propterygium would support true and augmented punters, but not non-punters, in an aquatic environment. All propterygia would fail on land. Geometric and linear morphometric analyses of 61 batoid pelvic girdles demonstrated that pelvic girdle shape can predict punting and swimming ability and taxonomic attribution to Order. / Characteristics of true punters' pelvic girdles, such as laterally facing fin articulations, large surface area formuscle attachment, and tall lateral pelvic processes are similar to characteristics of early sprawled-gait tetrapods' pelvic girdles. This dissertation demonstrates that punting is common in batoids, illustrates the convergent evolution of true punter and early tetrapod pelvic anatomy, and gives possible explanations for the restriction of elasmobranchs to aquatic habitats. / by Laura Jane Macesic. / Thesis ({Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Wai Yin Yee = 遺傳演算法的應用連續影像之人體動作捕捉 / 韋燕儀. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 113-115). / Text in English; abstracts in English and Chinese. / Wai Yin Yee = Yi zhuan yan suan fa de ying yong lian xu ying xiang zhi ren ti dong zuo bu zhuo / Wei Yanyi. / Abstract --- p.ii / 摘要 --- p.iv / Acknowledgement --- p.vi / Content --- p.vii / List of Figures --- p.x / List of Tables --- p.xviii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Human Motion Capture --- p.1 / Chapter 1.1.1 --- Optical Motion Capture --- p.3 / Chapter 1.1.2 --- Monocular Motion Capture --- p.4 / Chapter 1.2 --- Proposed Human Motion Capture System --- p.6 / Chapter 1.3 --- Organization --- p.8 / Chapter Chapter 2 --- Introduction of Genetic Algorithms --- p.10 / Chapter 2.1 --- Traditional Search Methods & Genetic Algorithms --- p.11 / Chapter 2.2 --- Mechanism of Genetic Algorithms --- p.14 / Chapter 2.3 --- A Simple Genetic Algorithm --- p.16 / Chapter 2.3.1 --- Initialization --- p.16 / Chapter 2.3.2 --- Evaluation --- p.17 / Chapter 2.3.3 --- Selection --- p.18 / Chapter 2.3.4 --- Genetic Operation --- p.19 / Chapter 2.3.5 --- Termination --- p.23 / Chapter 2.4 --- Convergence Proof for GA --- p.24 / Chapter 2.5 --- Proposed Modified Genetic Algorithm --- p.26 / Chapter 2.6 --- Effectiveness of the Proposed Modified GA on Function Optimization --- p.28 / Chapter 2.6.1 --- Function 1 - Unimodal function --- p.28 / Chapter 2.6.2 --- Function 2 - Sine function --- p.35 / Chapter 2.6.3 --- Function 3 - Foxhole function --- p.39 / Chapter 2.6.4 --- Function 4 - Discrete function --- p.41 / Chapter Chapter 3 --- Pre-processing I - Articulated Stick Model --- p.44 / Chapter 3.1 --- Background Knowledge of Human Skeleton --- p.44 / Chapter 3.2 --- Simplified Humanoid Articulated Stick Model --- p.44 / Chapter Chapter 4 --- Pre-Processing II - Reference Lengths & 2-D Frame Scale --- p.48 / Chapter 4.1 --- Optimization Approach --- p.54 / Chapter 4.1.1 --- Parameters Range --- p.62 / Chapter 4.1.2 --- GA Formulation --- p.63 / Chapter 4.2 --- Triangulation approach --- p.63 / Chapter 4.3 --- Experiments & Discussion --- p.66 / Chapter 4.3.1 --- Experiment One: Synthetic sequences --- p.67 / Chapter 4.3.2 --- Experiment Two: Real image sequences --- p.71 / Chapter Chapter 5 --- Pre-Processing III - Possible Depths --- p.76 / Chapter Chapter 6 --- Resolving Depth Ambiguity by GA --- p.83 / Chapter 6.1 --- Smoothness Assumption --- p.83 / Chapter 6.2 --- Kinematic Constraint --- p.85 / Chapter 6.3 --- GA Formulation --- p.85 / Chapter 6.4 --- Proposed Constrained GA --- p.86 / Chapter 6.5 --- Implementation and Experiments --- p.87 / Chapter 6.5.1 --- Experiment One: Synthetic sequences --- p.88 / Chapter 6.5.2 --- Experiment Two: Real image sequences --- p.105 / Chapter Chapter 7 --- Conclusion --- p.111 / Bibliography --- p.113 / Appendix A Description of Rotating Angles --- p.116

A hérnia perineal é uma das afecções cirúrgicas frequentemente observadas na rotina da clínica cirúrgica de pequenos animais e acometem na sua maioria, cães machos, não castrados e acima de cinco anos. Apresenta elevado índice de recidivas e complicações pós-cirúrgicas, e devido a este fato, muitas técnicas foram preconizadas e utilizadas para a sua correção. Os objetivos do presente estudo foram avaliar a locomoção cinética dos cães com hérnia perineal bilateral, submetidos à técnica de transposição do músculo semitendinoso antes e após a sua transposição; verificar a capacidade de adaptação do membro pélvico operado, após a transposição do semitendinoso, até 90 dias de pós-operatório e analisar a viabilidade dessa técnica de reparação em casos de hérnia perineal bilateral. Foram operados onze cães com diagnostico de hérnia perineal bilateral, no Serviço de Cirurgia de Pequenos Animais junto ao Hospital Veterinário da Faculdade de Medicina Veterinária da Universidade de São Paulo (HOVET-FMVZ / USP). Todos foram submetidos à técnica de transposição do músculo e avaliados com exames baropodométricos antes e após a cirurgia, nos períodos de 30, 60 e 90 dias pós-operatório. As variáveis pico de força vertical (PFV) e impulso vertical (IV) foram utilizadas como parâmetros para a análise de mudanças na locomoção. A PFV e IV não mostraram diferença estatística (p&gt; 0,05) entre os membros operados e não operados, respectivamente (18,62 0 &plusmn 4,93 e 18,51 &plusmn 3,75), indicando que não houve alteração na locomoção dos cães após a transposição do músculo semitendinoso. A diferença no comportamento dessas variáveis no período pré-operatório nos permitiu aferir que o desconforto provocado pela hérnia perineal possa interferir na locomoção do animal gerando assimetria, considerando que após o procedimento operatório a simetria da locomoção apresentou valores mais compatíveis dentro do normal. As diferenças em PFV e IV, embora não significativas, nos dá uma idéia da recuperação desses cães e sugere que a transposição não afeta a função locomotora do membro operado. / A perineal hernia is a surgical lesion frequently observed in surgical clinic for small animals, affecting mainly dogs neutered over five years. Has a high recurrence rate and postoperative complications, and due to this fact, many techniques have been proposed and used for its correction. The objectives of this study were to evaluate the kinetic movement of dogs with bilateral perineal hernia, submitted to the technique of transposition of the semitendinosus muscle before and after its implementation and verify the adaptability of the pelvic limb surgery, after transposition of the semitendinosus 90 days of postoperatively and analyze the feasibility of this technique of repair in cases of bilateral perineal hernia. Eleven dogs were operated with diagnosis of bilateral perineal hernia, on the Surgery Service of the animal small of the Veterinary Hospital of the Faculty of Veterinary Medicine, University of São Paulo (HOVET-FMVZ / USP). All patients underwent the technique of muscle transposition and evaluated baropodometric examinations before and after surgery, in periods of 30, 60 and 90 days postoperatively. The variables peak vertical force (PFV) and vertical impulse (VI) were used as parameters for the analysis of changes in locomotion. The PFV and IV showed no statistical difference (p&gt; 0.05) between the operated and non operated limbs, respectively (18.62 &plusmn 4.93 and 18.51 &plusmn 3.75), indicating that there was no change in locomotion dogs after the transposition of the semitendinosus muscle. The difference in behavior of these variables in the preoperative period allowed us to infer that the discomfort caused by perineal hernia can interfere with the locomotion of the asymmetry animal generating, whereas after the operative procedure, the symmetry of locomotion showed more next values of the normal. The difference in PFV and IV, although not significant, gives us an idea of the recovery of these dogs and suggests that the transposition does not affect the motor function of the limb.

Les travaux réalisés lors de cette thèse ont porté sur le cortex moteur et les troubles de la marche de patients atteints de la maladie de Parkinson (MP). L’atteinte fonctionnelle des aires motrices corticales dans la MP et leur implication dans la physiopathologie des désordres moteurs a surtout été établie à partir de données issues des aires corticales des membres supérieurs. L’analyse électrophysiologique par stimulation magnétique transcranienne réalisée dans ces travaux de thèse a exploré les aires motrices corticales des membres inférieurs et révélé des troubles d’excitabilité différents de ceux classiquement décrits dans les aires corticales des membres supérieurs. En effet, il ressort principalement de l’étude sur le membre inférieur une diminution de la facilitation intracorticale (FIC) alors que la littérature décrit essentiellement pour les aires motrices corticales des membres supérieurs une altération des mécanismes inhibiteurs intracorticaux. Les anomalies corticales mises en évidence sont corrélées avec les paramètres locomoteurs affectés par la maladie, longueur d’enjambée et vitesse de marche. L’analyse des patients avec et sans traitement a permis de montrer que la supplémentation dopaminergique agit à la fois au niveau cortical et locomoteur normalisant partiellement les déficits observés. Les anomalies de FIC des aires corticales motrices des membres inférieurs paraissent donc être impliquées dans la physiopathologie des troubles de la marche dans la MP et pourraient de ce fait constituer un paramètre d’évaluation et un objectif thérapeutique de choix. L’utilisation de la stimulation magnétique transcranienne répétitive couplée à la neuronavigation permettrait d’explorer cette dernière piste. / This thesis aims to study the relationships between motor cortex impairment and locomotor disorders in Parkinsonian patients (PP). Most of the previous studies have focused on the upper limb cortical areas showing the existence of an imbalance in cortical excitability, which mainly evolves towards a state of impaired intracortical inhibition. However, just a few studies have been devoted so far to the exact cortical abnormalities responsible for Parkinsonians’ gait disorders. The transcranial magnetic stimulation (TMS) studies presented here demonstrate that the excitability abnormalities occurring in PP differ between the cortical areas associated with the lower and upper limbs, since defective intracortical facilitation (ICF) processes were mainly detected in the lower limbs cortical areas. Furthermore, these specific excitability abnormalities identified seem to be involve in the genesis of the hypokinetic locomotor component since correlations were established between the ICF level and the shortened stride length (and by correlates, with the reduced velocity). Patients were assessed with and without dopaminergic substitution treatment (DST). We found that DST modified significantly both the cortical excitability abnormalities and the defective locomotor parameters. Impaired facilitatory processes in lower limbs cortical areas may be involved in the pathophysiology of gait disorders in PD. This hypothesis should be addressed in an experiment coupling repetitive TMS and neuronavigation.