Nos últimos anos, o treinamento aeróbio vem sendo empregado como forma de recuperação da marcha em pessoas pós-acidente vascular cerebral. O objetivo desta Tese foi avaliar os efeitos do treinamento aeróbio em piscina e em esteira rolante na marcha de indivíduos hemiparéticos crônicos. Participaram 12 pessoas, randomizadas por sorteio para Grupo Piscina e Grupo Esteira. Para as avaliações funcionais, os testes e escalas foram divididos de acordo com a Classificação Internacional de Funcionalidade, Incapacidade e Saúde: Avaliação Fugl-Meyer; a Escala de equilíbrio de Berg, Escala de avaliação do controle postural para pacientes pós-acidente vascular cerebral, Timed Up and Go Test e o Questionário de qualidade de vida SF-36. Na avaliação biomecânica foram avaliados os parâmetros cinemáticos de amplitude de movimento, ângulo mínimo e máximo da articulação do joelho e tornozelo e parâmetros eletromiográficos (EMG) dos músculos tibial anterior, gastrocnêmio lateral, reto da coxa, vasto lateral, bíceps da coxa, semitendíneo. Foi realizada análise de variância para inferir o efeito do treinamento aeróbio em ambos os grupos. Para estudar o comportamento das variáveis eletromiográficas em função das avaliações funcionais foi realizada a análise de regressão linear múltipla. O treinamento aeróbio melhorou o comprometimento sensório-motor, equilíbrio, agilidade e qualidade de vida relacionada à saúde dos participantes de ambos os grupos, como alterações nos padrões eletromiográficos dos músculos na locomoção dos participantes de ambos os grupos. Não houve efeito do treinamento aeróbio para os parâmetros cinemáticos das articulações analisadas. Houve a fraca relação entre os parâmetros EMG e as variáveis funcionais. Os participantes foram beneficiados pela prática do treinamento aeróbio que propiciou a melhora da funcionalidade dos participantes, independente do meio o qual foi realizado / Stroke is the leading cause of adult disability in the world. Clearly, walking retraining is a major goal in a rehabilitation program for person with stroke. Our study was designed to evaluate the effect of a training program involving both treadmill and aquatic walking to reduce the disability due to poor walking performance in chronic stroke persons. Twelve participants were randomly assigned to treadmill group and aquatic group for the 9 week program (3 days/week) progressive graded, high-intensity aerobic treadmill exercise or aquatic exercise. Data from functional assessments were selected according to levels of the International Classification of Functioning, Disability and Health: Fulg-Meyer scale to body function, Brazilian Berg balance scale, Timed and up & go test and The Postural Assessment Scale for Stroke Patients to activity and Medical Outcomes Study short-form 36-item questionnaire (SF-36) to participation. Biomechanical data were the lower limb kinematic variables (peak and minimal angle and maximal range) and surface electromyogram signals was recorded from tibialis anterior, lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and semitendinosus bilaterally during gait. A five-way analysis of variance was performed to test for differences among groups, phases, muscles, sides and gait phases. Multiple linear regression models were ran to examine the relationships between functional assessment and the electromyography variables. The aerobic training improved the functional variables in both groups. The electromyography variables showed influence of the training program in both groups. Weak relationship exists between functional assessment and the electromyography variables. The aerobic training programs in chronic hemiparetic stroke were beneficial and improving functional status in stroke person for both groups

Nos últimos anos, o treinamento aeróbio vem sendo empregado como forma de recuperação da marcha em pessoas pós-acidente vascular cerebral. O objetivo desta Tese foi avaliar os efeitos do treinamento aeróbio em piscina e em esteira rolante na marcha de indivíduos hemiparéticos crônicos. Participaram 12 pessoas, randomizadas por sorteio para Grupo Piscina e Grupo Esteira. Para as avaliações funcionais, os testes e escalas foram divididos de acordo com a Classificação Internacional de Funcionalidade, Incapacidade e Saúde: Avaliação Fugl-Meyer; a Escala de equilíbrio de Berg, Escala de avaliação do controle postural para pacientes pós-acidente vascular cerebral, Timed Up and Go Test e o Questionário de qualidade de vida SF-36. Na avaliação biomecânica foram avaliados os parâmetros cinemáticos de amplitude de movimento, ângulo mínimo e máximo da articulação do joelho e tornozelo e parâmetros eletromiográficos (EMG) dos músculos tibial anterior, gastrocnêmio lateral, reto da coxa, vasto lateral, bíceps da coxa, semitendíneo. Foi realizada análise de variância para inferir o efeito do treinamento aeróbio em ambos os grupos. Para estudar o comportamento das variáveis eletromiográficas em função das avaliações funcionais foi realizada a análise de regressão linear múltipla. O treinamento aeróbio melhorou o comprometimento sensório-motor, equilíbrio, agilidade e qualidade de vida relacionada à saúde dos participantes de ambos os grupos, como alterações nos padrões eletromiográficos dos músculos na locomoção dos participantes de ambos os grupos. Não houve efeito do treinamento aeróbio para os parâmetros cinemáticos das articulações analisadas. Houve a fraca relação entre os parâmetros EMG e as variáveis funcionais. Os participantes foram beneficiados pela prática do treinamento aeróbio que propiciou a melhora da funcionalidade dos participantes, independente do meio o qual foi realizado / Stroke is the leading cause of adult disability in the world. Clearly, walking retraining is a major goal in a rehabilitation program for person with stroke. Our study was designed to evaluate the effect of a training program involving both treadmill and aquatic walking to reduce the disability due to poor walking performance in chronic stroke persons. Twelve participants were randomly assigned to treadmill group and aquatic group for the 9 week program (3 days/week) progressive graded, high-intensity aerobic treadmill exercise or aquatic exercise. Data from functional assessments were selected according to levels of the International Classification of Functioning, Disability and Health: Fulg-Meyer scale to body function, Brazilian Berg balance scale, Timed and up & go test and The Postural Assessment Scale for Stroke Patients to activity and Medical Outcomes Study short-form 36-item questionnaire (SF-36) to participation. Biomechanical data were the lower limb kinematic variables (peak and minimal angle and maximal range) and surface electromyogram signals was recorded from tibialis anterior, lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and semitendinosus bilaterally during gait. A five-way analysis of variance was performed to test for differences among groups, phases, muscles, sides and gait phases. Multiple linear regression models were ran to examine the relationships between functional assessment and the electromyography variables. The aerobic training improved the functional variables in both groups. The electromyography variables showed influence of the training program in both groups. Weak relationship exists between functional assessment and the electromyography variables. The aerobic training programs in chronic hemiparetic stroke were beneficial and improving functional status in stroke person for both groups

L'hémiparésie est une des déficiences fréquemment observée après un accident vasculaire cérébral (AVC). Elle s’accompagne d’une gestion anormale de la co-contraction musculaire et des déficits de production de force qui contribuent de manière significative à réduire la performance de la marche. Une réorganisation des stratégies musculaires est mise en place pour répondre aux contraintes de stabilité et de propulsion du centre de masse au cours de la marche. Cependant, la littérature reporte très peu de données sur les actions musculaires des membres, parétique et non-parétique, au cours de la marche. De plus, les patterns de co-contraction ont été évalués à partir des seules données EMG chez les patients post-AVC. Par ailleurs, les patients post-AVC présentent une fatigabilité plus importante que les individus sains. Alors que plusieurs facteurs sont impliqués dans la fatigue, le rôle de la co-contraction reste mal connu. L’objectif principal de ce travail était de caractériser les altérations des stratégies musculaires des membres inférieurs chez des patients hémiparétiques post-AVC au cours de la marche et lors de la fatigue induite par des contractions maximales volontaires concentriques isocinétiques. Ce travail introduit l'utilisation novatrice d'une modélisation neuromusculo-squelettique assistée par EMG pour estimer les forces musculaires générées autour des articulations du genou et de la cheville au cours de la marche chez des patients post-AVC. De plus, nous avons montré qu’une quantification de la co-contraction à partir des moments musculaires est préférable par rapport à des mesures EMG. Les résultats ont montré que les forces réduites développées par les fléchisseurs plantaires de la cheville et les extenseurs du genou du côté parétique seraient à l’origine des troubles de la marche hémiparétique. Les forces musculaires élevées produites par les quadriceps et les fléchisseurs du genou du côté nonparétique, ainsi que la force élevée générée par les fléchisseurs du genou du côté parétique, par rapport aux sujets sains, pendant la phase d’appui correspondrait à une réorganisation comportementale, permettant d’augmenter la stabilité et d’ajuster la propulsion du centre de masse. Cette réorganisation des patterns de coordination musculaire se manifeste également par des niveaux élevés de co-contraction (basée sur les moments musculaires) observés du côté parétique et non-parétique au cours de la marche. Il s’agit d’une stratégie d'adaptation permettant d’améliorer la stabilité articulaire. Cependant, la cocontraction plus élevée au cours de la marche peut contribuer à l’augmentation du coût énergétique chez les patients et entraîner une fatigue plus rapide. L’étude de la fatigue neuromusculaire chez les patients post-AVC a mis en évidence une fatigabilité moindre par rapport aux sujets sains en présence d’un niveau plus élevé de co-contraction (basée sur les données EMG). Le déclin de l’activité EMG agoniste lors de contractions concentriques répétées, s’est produit parallèlement à un déclin de l’activité EMG antagoniste diminuant la force d’opposition au mouvement et entraînant une moindre diminution du moment net. Ceci semble être un mécanisme potentiel par lequel la production du moment net est préservée chez les patients post-AVC qui sont intrinsèquement plus faibles. Les résultats de ce travail soulignent l’importance de développer des programmes de rééducation centrés sur le renforcement des fléchisseurs plantaires et des extenseurs du genou et sur la sélectivité du contrôle des mouvements tel que l’entraînement en puissance. / Hemiparesis is one of the most frequent deficits after stroke. It is accompanied by an abnormal muscle co-contraction pattern and an altered force production that significantly contribute to reduced gait performance. These alterations lead to a reorganization of muscle coordination patterns to ensure stability and adjust the propulsion of the center of mass during walking. However, less is known about muscle actions in the paretic and non-paretic lower limbs during walking. In addition, co-contraction patterns were evaluated from only EMG data in post-stroke patients. Furthermore, post-stroke patients manifest higher levels of fatigability than healthy individuals. While several factors are involved in fatigue, the role of co-contraction remains poorly understood. The main objective of this thesis was to characterize the alterations of the muscle strategies of the lower limbs in post-stroke hemiparetic patients during walking and during fatigue induced by isokinetic concentric maximal contractions. This thesis introduces the novel use of an EMG-driven modelling approach to measure muscle forces generated around the knee and ankle joints of the paretic and non-paretic lower limbs during gait in post-stroke patients. In addition, we have shown that quantification of co-contraction from muscle moments is preferable compared to EMG measurements. The results showed that the reduced forces exerted by the plantar-flexors and the knee-extensors on the paretic side, gives a possible explanation for hemiparetic gait abnormalities. Increased forces generated by the knee-flexor and knee-extensor muscles on the non-paretic side, as well as increased force generated by the knee flexors on the paretic side, compared to healthy subjects, during the stance phase would be a behavioral reorganization to better support body weight and properly adjust the forward center of mass. This reorganization of muscle coordination patterns is also reflected by the increased levels of co-contraction (based on muscle moments) observed on the paretic and non-paretic side during walking. This seems to be an adaptive, compensatory strategy to ensure postural stability. However, increased co-contraction during walking can contribute to an increased energy cost in patients and lead to a more rapid fatigue development. The study of neuromuscular fatigue in post-stroke patients showed less fatigability compared to healthy subjects, in the presence of a higher level of co-contraction (based on EMG data). Decreasing agonist EMG during repeated concetric contractions, occurred in parallel with decreasing antagonist EMG, reducing the relative opposing force and resulting in a less decline in net torque. This seems to be a potential mechanism by which net torque output is preserved in post-stroke patients who are inherently weaker. The results of these studies underline the importance of developing rehabilitation programs focused on the strengthening of plantar flexors and knee extensors and on the selectivity of movement control, such as power training.