J’ai étudié trois protéines qui participent à deux vois différentes de méchano-transduction qui est la conversion des stimuli physiques en un signal biochimique.Dans une culture cellulaire en 2D, lorsque les cardiomyocytes sont étirés, MLP est transloqué vers le noyau. Sans translocation, les cellules ne parviennent pas à répondre à la stimulation. Les patients porteurs de mutations dans MLP développent une cardiomyopathie comme les souris MLP knock-out (MLP-/-). Mon objectif a été d’élucider le rôle de MLP dans ces cardiomyopathies en surexprimant des mutations de MLP dans les cardiomyocytes isolés des souris MLP-/- néonataux. Dans les cultures 2D mais pas 3D, MLP n’était pas transloqué vers le noyau après l’étirement des cellules. Bien que je n’aie pas pu résoudre ce problème, j’ai mis au point les expériences nécessaires à la poursuite de ce projet.Nesprins s’intègrent dans un complexe transmembranaire de l’enveloppe nucléaire (EN), le LINC complexe, qui connecte le cytosquelette à l’intérieur du noyau. Les myoblastes isolés des patients porteurs des mutations de Nesprin ou de Lamin, qui est associé au LINC complexe, ont présenté des noyaux déformés ainsi que des anomalies de réponses méchanosensibles : Si cultivées sur supports mous, les cellules affichaient un niveau élevé de fibres musculaires stressées et d’adhésions focales. Le knock-down de FHOD, une cible en aval de ROCK et SRC, qui également étaient actives dans ces myoblastes, a réduit ce phénotype. Bien que l’on ait émis l’hypothèse que les mutations dans Nesprins et Lamins conduisent à une instabilité mécanique de l’EN, ces résultats indiquent que les voies de signalisation par l’EN sont perturbées aussi. / I studied three striated muscle proteins that are participating in two different pathways of mechanotransduction, which is the translation of a physical stimulus into a biochemical signal.When isolated cardiomyocytes are stretched in 2D, MLP shuttles to the nucleus. Without shuttling MLP, these cells fail to respond to the stretch stimulus. Human patients with MLP-mutations develop cardiomyopathies, as well as mice with a knock-out of MLP (MLP-/-). By expressing mutated MLP in neonatal cardiomyocytes of MLP-/- mice, I wanted to elucidate the role of mutant MLP. Surprisingly, MLP did shuttle after stretching of 2D but not 3D cell cultures. Although I could not solve this issue, I prepared the setup for subsequent experiments.Nesprins are part of the nuclear envelope (NE) spanning LINC complex, which connects the cytoskeleton with the nucleus. Myoblasts from patients with mutations in Nesprins or LINC-associated Lamins displayed deformed nuclei and had defects in mechanosensitive responses with an elevated level of stress fibers and focal adhesions on soft surfaces. This phenotype could be rescued by knock-down of formin FHOD1, a downstream target of ROCK and SRC, which also were highly active in the mutant cells. While mutations in Nesprins and Lamins are thought to lead to mechanical instability of the NE, these results indicate that signaling pathways through the NE are disturbed as well.

Title: Optimization of warm-up before speed-strenght loading Objectives: The aim of this work is to compare three variants of warming up and to determine the most appropriate one before speed-strenght loading. Methods: The test group consisted of 15 male students of the Faculty of Physical Education and Sport at The Charles University at the age of 22 -26 years. The tested subjects underwent 4 tests within 4 weeks. The first test was used to determine the 1 RM bench press and leg-press, the results of which we needed for the proper determination of the weights for the following protocols. The other three measurement protocols include three warm-up (base, a speed-strenght and toning), followed by a test of explosive strength in arms and legs. Countermovement vertical jump height with arm swing was used for legs testing and medicine ball shoot-up in supine position was used for arms testing. Results: This research shows that best results in the countermovement vertical jump height with arm swing were achieved after the speed-power warm-up. The best results in medicine ball shoot-up in supine position were achieved after the basic warm up, but results are not statistically significant for these testing. Keywords: Warm-up, dynamic stretching, speed-force loading, toning, explosive force, testing

Orientador: Luiz Eduardo Barreto Martins / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-26T19:59:48Z (GMT). No. of bitstreams: 1 Muramatsu_LucioVitorelli_M.pdf: 2705726 bytes, checksum: 4fa3509cfece4d833e50560b76383887 (MD5) Previous issue date: 2015 / Resumo: O objetivo do presente estudo foi investigar alterações neuromusculares e biomecânicas induzidas por diferentes velocidades de execução durante o ciclo de alongamento-encurtamento (CAE) realizado de forma contínua. Doze homens (25,0 ± 3,0 anos, 1,80 ± 0,05 m, 79,6 ± 8,8 kg e 8,0 ± 3,2% de gordura corporal) e três mulheres (29,0 ± 3,0 anos, 1,60 ± 0,06 m, 61,6 ± 2,1 kg e 17,1 ± 2,5% da gordura corporal) participaram do estudo. Os voluntários realizaram 3 protocolos com distintas velocidades de execução. O controle das velocidades foi realizado pelo tempo destinado à execução de cada CAE (Lento = 4 s, Médio = 2 s e Rápido = 1 s por ciclo). Cada protocolo consistiu de 20 repetições (CAE) com 10% de 1RM e 5 min de intervalo, realizados no exercício de extensão do joelho. Velocidade angular, aceleração angular, torque e eletromiografia de superfície (EMG) dos músculos vasto lateral, vasto medial e reto femoral foram acessadas. A execução do CAE em altas velocidades requer alta desaceleração no final das ações excêntricas (EXC) e alta aceleração no início das ações concêntricas (CON), aumentando assim o torque e a atividade EMG nesses momentos. Durante o protocolo Rápido, a atividade EMG da EXC foi maior que a CON. A maior produção de torque e atividade EMG no final da EXC potencializa o início da CON, diminuindo a atividade EMG nessa fase do movimento. Portanto, o CAE realizado com altas velocidades de execução (~160°/s) aumenta a eficiência neuromuscular no começo da CON, induzindo maior atividade EMG durante a ação EXC em comparação com a CON / Abstract: The aim of the present study was to investigate the neuromuscular and biomechanical changes induced by different speed-controlled stretch-shortening cycles (SSCs). Twelve men (24.8 ± 2.9 years, 1.80 ± 0.05 m, 79.6 ± 8.8 kg, and 8.0 ± 3.2% of body fat) and three women (29.0 ± 3.6 years, 1.60 ± 0.06 m, 61.6 ± 2.1 kg and 17.1 ± 2.5% of body fat) participated in the study. The three different speed-controlled SSCs (Slow = 4 s, Medium = 2 s and Fast = 1 s per cycle), were performed on the knee extension machine, consisting of 20 repetitions (SSCs) with 10% of 1RM and 5 min rest. Angular velocity and acceleration, torque and Surface EMG of the vastus lateralis, vastus medialis, and rectus femoris muscles were recorded. During the Fast, EMGRMS of the eccentric (ECC) phase was higher than in the concentric (CON). The acceleration, torque and EMG activity increased in the later phase of the ECC and in the early phase of the CON. Higher torque production and EMG activity in the later part of ECC potentiates the early phase of CON, decreasing EMG activity of these action. Therefore, fast SSCs (160°/s) increases neuromuscular efficiency of CON and induces higher EMG activity in ECC compared to CON / Mestrado / Biodinamica do Movimento e Esporte / Mestre em Educação Física

INTRODUÇÃO: Fibromialgia (FM) é uma síndrome caracterizada por dor severa, difusa e crônica, e uma magnitude de sintomas. Exercícios de flexibilidade são indicados para o tratamento de dor crônica por disfunções osteomioarticulares. O aprendizado sobre a FM, comportamentos saudáveis e perspectivas positivas no processamento de informações (resiliência) são imprescindíveis para os indivíduos com FM. O objetivo deste estudo foi comparar o efeito de dois tratamentos para FM: Tratamento A - exercícios de flexibilidade em cadeias musculares baseados no método de Reeducação Postural Global associados à abordagem educativa segundo referencial da terapia cognitivo-comportamental (TCC) e Tratamento B - exercícios de flexibilidade segmentar associados à abordagem educativa segundo referencial da TCC. MÉTODOS: Quarenta pacientes com FM foram randomizados em dois grupos: A e B, com 20 em cada. Os tratamentos tiveram 10 sessões de atendimento individual, uma vez por semana. Foram feitas duas avaliações (linha de base e no final do tratamento). As variáveis foram intensidade da dor (EVA), multidimensionalidade da dor (Questionário McGill de dor), limiar de dor nos tender points (dolorimetria), atitudes frente à dor crônica (IAD-breve), impacto da FM na qualidade de vida (QIF), postura corporal (PAS/SAPO), flexibilidade (teste sentar-e-alcançar) e controle postural (mCTSIB). RESULTADOS: Os grupos apresentaram, no final do tratamento, menor intensidade da dor (linha de base vs. final; grupo A: 6 ± 1,8 vs. 2,2 ± 1,6cm, p < 0,01; grupo B: 6,4 ± 2,1 vs. 2,5 ± 1,7cm, p < 0,01), menor severidade da dor (p < 0,05), maior limiar de dor (p <= 0,01), maior adaptação nas atitudes frente à dor crônica (p < 0,01) e menor escore total do QIF (linha de base vs. final; grupo A: 61 ± 19,8 vs. 38,2 ± 16,6, p < 0,01; grupo B: 57,2 ± 13,9 vs. 39,3 ± 11,5, p < 0,01). O grupo A mostrou diferença estatisticamente significante no alinhamento postural (cabeça, tronco e pelve), aumento no controle postural em uma condição sensorial e redução em duas condições sensoriais (p < 0,05); o grupo B mostrou diferença estatisticamente significante no alinhamento postural (cabeça e tronco) (p <= 0,05) e aumento no controle postural em duas condições sensoriais (p <= 0,02). Houve melhora clínica relevante na intensidade e severidade da dor, limiar de dor e qualidade de vida em ambos os grupos. No final do tratamento, não houve diferença estatisticamente significante entre os grupos nas variáveis de desfecho. CONCLUSÃO: Os dois tratamentos de fisioterapia reduziram a intensidade e severidade da dor, aumentaram o limiar de dor nos tender points, melhoraram as atitudes de enfrentamento à dor crônica e reduziram o impacto da FM na qualidade de vida em pacientes com FM. Os dois tratamentos de fisioterapia reduziram os escores dos critérios de diagnóstico da FM de 2010/2011 do Colégio Americano de Reumatologia em um nível que implica a ausência de FM no final dos tratamentos / INTRODUCTION: Fibromyalgia (FM) is a syndrome characterized by severe, diffuse, chronic pain and a multitude of symptoms. Flexibility exercises are indicated for the treatment of chronic musculoskeletal pain. Learning about FM, healthy behaviors, and positive perspectives in information processing (resilience) is imperative for individuals with FM. The aim of this study was to compare the effect of two treatments for FM: Treatment A -- flexibility exercises in muscle chains based on the Global Posture Reeducation method and used in concert with an educational approach rooted in cognitive behavioral therapy (CBT) and Treatment B -- segmental flexibility exercises used in concert with an educational approach rooted in CBT. METHODS: Forty patients with FM were randomized into two groups: A and B, with 20 in each. The two treatments were performed in ten individual sessions once a week. Two assessments were made, one at baseline and one at the end of treatment. The outcome variables were pain intensity (VAS), multidimensional pain (McGill Questionnaire), pain threshold at tender points (dolorimetry), attitudes toward chronic pain (SOPA-brief), impact of FM on quality of life (FIQ), body posture (PAS/SAPO), flexibility (sit-and-reach test) and postural control (mCTSIB). RESULTS: The groups presented, at the end of treatment, lower pain intensity (baseline vs. final; group A: 6 ± 1.8 vs. 2.2 ± 1.6cm, p < 0.01; group B: 6.4 ± 2.1 vs. 2.5 ± 1.7cm, p < 0.01), lower pain severity (p < 0.05), higher pain threshold (p<=0.01), greater adaptation in attitudes towards chronic pain (p < 0.01), and lower total FIQ score (baseline vs. final; group A: 61 ± 19.8 vs. 38.2 ± 16.6, p < 0.01; group B: 57.2 ± 13.9 vs. 39.3 ± 11.5, p < 0.01). The group A showed statistically significant difference in postural alignment (head, trunk and pelvis), an increase in postural control in one sensory condition and a reduction in two sensory conditions (p < 0.05); group B showed statistically significant difference in postural alignment (head and trunk) (p<=0.05), and an increase in postural control in two sensory conditions (p <= 0.02). There was a relevant clinical improvement in the intensity and severity of pain, pain threshold and quality of life in both groups. At the end of the treatment, there was no statistically significant difference between groups in the outcome variables. CONCLUSIONS: The two physiotherapy treatments reduced the intensity and severity of pain, increased pain threshold in tender points, improved attitudes towards chronic pain and reduced the impact of FM in the quality of life in patients with FM. The two physiotherapy treatments reduced the American College of Rheumatology 2010/2011 FM diagnostic criteria scores at a level that implies the absence of FM at the end of the treatments

Os pacientes com doença pulmonar obstrutiva crônica (DPOC), devido à obstrução brônquica e redução da retração elástica pulmonar apresentam o aumento do recrutamento da musculatura respiratória, predispondo à incoordenação toracoabdominal, aumentando o trabalho respiratório, provocando fadiga e dispnéia. O alongamento dos músculos respiratórios (AMR) poderia diminuir a atividade muscular, melhorar a sua capacidade contrátil e a mobilidade da caixa torácica otimizando a ventilação pulmonar, entretanto, estes efeitos nos músculos respiratórios permanecem desconhecidos. Objetivo: Avaliar os efeitos da adição do AMR associados à reabilitação pulmonar na mecânica ventilatória, na capacidade funcional e na atividade muscular em pacientes com DPOC. Método: Estudo randomizado e controlado incluiu 30 pacientes com DPOC que foram distribuídos aleatoriamente para os grupos: tratado (GT, n = 15) e controle (GC, n = 15). Todos os pacientes foram submetidos a 24 sessões de treinamento aeróbico duas vezes por semana. Além disso, o GT recebeu AMR e o GC recebeu o alongamento dos membros superiores e inferiores, antes dos exercícios aeróbicos. Foram avaliados: teste da capacidade funcional (teste de caminhada de 6 minutos, TC6), mecânica toracoabdominal (pletismografia optoeletrônica, POE) e atividade muscular respiratória (eletromiografia de superfície, EMG) durante o exercício. Os dados representam a variação (delta)=pós- - pré-avaliação, foi utilizado o teste t para comparar os grupos e o nível de significância foi fixado em 5%. Resultados: O GT apresentou o aumento da capacidade funcional (25,14m +) com a redução da sensação de dispneia após o TC6 (p < 0,01), quando comparado ao GC. Provavelmente está relacionado com a melhora do volume da caixa torácica (p < 0,01), capacidade ventilatória (p < 0,01) com o aumento do volume e da contribuição do compartimento abdominal (p < 0,01). Observamos também no GT a redução da atividade muscular (p < 0,01) com maior eficiência ventilatória (p < 0,006). Conclusão: Nossos resultados sugerem que a adição do AMR no treinamento aeróbio aumenta a capacidade funcional com diminuição da dispneia, melhora a eficácia da contração muscular e da capacidade ventilatória devido à maior participação do compartimento abdominal em pacientes com DPOC / Chronic obstructive pulmonary disease (COPD) patients due to bronchial obstruction and reduced lung elastic recoil present increased in the recruitment of respiratory muscles, predisposing an thoracoabdominal incoordination, major breathing work, causing fatigue and dyspnea. The respiratory muscles stretching (RMS) could decrease the muscle activity and improve their contractile capacity, chest wall mobility and optimize the pulmonary ventilation, however, this effect remains unknown. Objective: To evaluate the effects of adding the RMS associated with pulmonary rehabilitation in ventilatory mechanics, functional capacity and muscle activity in patients with COPD. Method: Randomized and controlled trial, enrolled 30 COPD patients who were randomly allocated into treatment (TG, n = 15) and control (CG, n = 15) groups. All patients underwent 24 sessions of aerobic training twice a week. In Addition, TG received RMS and CG received upper and lower limb stretching before aerobic exercises. Were evaluated: functional capacity (6-minute walking distance test, 6MWDT), thoracoabdominal mechanics (optoelectronic plethysmography, OEP) and respiratory muscle activity (surface electromyography, EMG) during exercise. The data represents the change (delta) = post- - pre-evaluation, a t-test was used to compare the groups, and the significance level was set at 5%. Results: TG showed improvement in the functional capacity (25,14m +) with decrease of the dyspnea sensation after the 6MWDT (p < 0.01), compared with CG. Probably is related with increased of chest wall volume (p < 0.01), ventilatory capacity (p < 0.01), volume and the contribution of the abdominal compartment (p < 0.01). We also observed in the TG, a reduction of respiratory muscle activity (p < 0,01) and the ratio between volume displaced (p < 0,006). Conclusion: Our results suggest that the addition of RMS to aerobic training increases the functional capacity with dyspnea reduction, improvement of efficacy of respiratory muscle contraction and ventilatory capacity due to higher participation of the abdominal compartment in patients with COPD

Objetivo: Investigar o efeito da laserterapia de baixa intensidade (LBI) e do alongamento estático, combinados ou não, em pessoas com osteoartrite de joelho (OAJ). Método: Foram randomizados 145 sujeitos de 50 a 75 anos com OAJ em cinco grupos de intervenção (n=29 cada): Laserativo+Along; Laserplacebo+Along; Along; Laserativo e controle. A laserterapia (GaAs; 904nm; 40mW; 3J/ponto; 27J/joelho) consistiu de nove sessões nos grupos de terapia combinada e 24 quando monoterapia. O alongamento foi composto por sete exercícios repetidos por 24 sessões. O controle recebeu uma cartilha educacional. A frequência de tratamento foi de 3x/sem. A variável primária foi a intensidade da dor medida pela Escala Visual Analógica e as variáveis secundárias incluídas foram domínios dor, função, rigidez e escore total do questionário Western Ontario and McMaster Universities Arthritis Index (WOMAC), funcionalidade avaliado pelo Lequesne, mobilidade pelo Timed Up and Go, amplitude de movimento do joelho (ADMJ) pela goniometria e encurtamento de isquiotibiais (IQT) pelo ângulo poplíteo. O nível de significância foi de ?=0,05. Resultados: Nos grupos de terapia combinada, não foi observada diferença entre o laser ativo e placebo (p>0,05). Ao final do estudo, os grupos demonstraram, em média, ganho relativo significativo na dor durante AVDs (50%), WOMAC total (39%), funcionalidade (30%) e mobilidade (20%) em comparação ao controle (p < 0,001). Houve melhora de 43% no encurtamento de IQT e de 9% no ganho de ADMJ nos grupos de terapia combinada em relação ao controle (p < 0,001 e p=0,02, respectivamente). Conclusão: LBI e alongamento estático, quando isolados, foram efetivos na melhora da dor, funcionalidade, mobilidade e nos domínios dor, função e escore total do WOMAC. A LBI nos grupos de terapia combinada não foi superior à aplicação placebo. Portanto, não devemos desconsiderar a contribuição do efeito placebo no resultado do tratamento isolado. A LBI combinada ao alongamento não promoveu benefícios adicionais em relação ao alongamento de forma isolada / Objective: To investigate the effect of low-level laser therapy (LLLT) and static stretching, in combination and as monotherapy, in people with knee osteoarthritis (KOA). Methods: 145 people aged 50-75 years with KOA were randomly allocated to five groups (each n=29): Laseractive+Stretch, Laserplacebo+Stretch, Stretch, Laseractive and control. The laser therapy (GaAs; 904nm; 40mW; 3J/point; 27J/knee) consisted of nine sessions in the combined treatment groups and 24 when used as monotherapy. Stretching consisted of seven exercises repeated for 24 sessions. The control group received an educational booklet. Treatment frequency was 3 times/week. The primary outcome was pain intensity measured by Visual Analogue Scale and the secondary outcomes included pain, function and stiffness\' domains and total score of Western Ontario and McMaster Universities Arthritis Index (WOMAC), function assessed by Lequesne, mobility by Timed Up and Go, knee range of motion (KROM) by goniometry and hamstring shortening by popliteal angle. Results: In the combined treatment groups, there was no difference between the laser active and placebo (p > 0.05). At the end of the study, the treatment groups demonstrated, on average, a significant relative gain in pain (50%), total WOMAC (39%), function (30%) and mobility (20%) when compared to control (p < .001). For the combined treatment groups there was a 43% improvement in hamstring shortening (p <.001) and 9% improvement in KROM (p=0.02) when compared to control group. Conclusion: LLLT and stretching exercises, as monotherapy, were effective in reducing pain and improving function, mobility and the domains pain and function as well as the total score of WOMAC. The LLLT in the combined groups was not superior to the placebo application. Thus, we should not discard the contribution of the placebo effect in the result of the LLLT as monotherapy. The LLLT combined with stretching did not promote additional benefits compared to stretching alone

A instabilidade articular é responsável pelo desenvolvimento de lesões degenerativas incapacitantes que comprometem o desempenho funcional. Compreender os processos desenvolvidos para estabilização dinâmica articular é um desafio para pesquisadores das mais diversas áreas. O presente estudo propõe o uso da abordagem Biomecânica para reconhecer os mecanismos relacionadas ao processo de estabilização dinâmica articular, por meio de três diferentes condições experimentais. No experimento 1 foi analisada a Força de Reação do Solo (FRS) e a cinemática 3-D no andar, correr e saltar de portadores (n=10) e não portadores de instabilidade crônica (n=10) do tornozelo. No experimento 2 foi analisada a Eletromiografia dos músculos tibial anterior, fibular longo, fibular curto e gastrocnêmio lateral de portadores (n=14) e não portadores de instabilidade crônica (n=14) do tornozelo antes e após um protocolo de indução à fadiga muscular. No experimento 3 (n=20) foi analisado o efeito do exercício de alongamento muscular estático passivo dos músculos fibular longo e fibular curto na simulação da entorse do tornozelo. Nos protocolos de locomoção foram encontrados no lado acometido picos tardios e aumento dos Impulsos da FRS. No início da fase de apoio o tornozelo instável no andar aumentou a dorsiflexão, no correr aumentou a eversão e no saltar diminuiu a inversão e aumentou a dorsiflexão. Tais estratégias representam a tentativa de melhorar a estabilidade dinâmica articular. No entanto, a variação angular da articulação no plano sagital e frontal aumentaram, sugerindo que há mais amplitude de movimento no tornozelo acometido e maior estresse sobre os estabilizadores passivos locais. Em condições de fadiga muscular, após simulação da entorse, indivíduos com articulações saudáveis aumentam a rigidez articular e a intensidade de contração dos eversores do tornozelo, antecipadamente a perturbação, diferente de portadores de instabilidade crônica. A execução do exercício de alongamento dos músculos fibulares longo e curto, seguido da simulação da entorse, gerou o retardo da resposta motora e diminuição da intensidade de ativação. Desta forma, as estratégias desenvolvidas por portadores de instabilidade crônica podem ser relacionadas à causa e/ou consequência do quadro, a fadiga muscular altera o desenvolvimento de estratégias de proteção e o exercício de alongamento pode prejudicar a estabilização dinâmica articular / Joint instability is associated with degenerating injuries that lead to functional incapacitation. Knowing the process involved in joint dynamic stabilization is a challenge to researchers in many fields. This study proposes the use of a biomechanical approach to recognize the mechanisms involved in joint stabilization through three different experimental conditions. The first experiment analyzed the Ground Reaction Force (GRF) and the 3D kinematics in participants with (n=10) and without (n=10) chronic ankle instability during walking, running and jumping. The second experiment analyzed the Electromyography signal of tibialis anterior, peroneus longus, peroneus brevis e gastrocnemius lateralis in participants with (n=14) and without (n=14) chronic ankle instability before and after a muscle fatigue protocol. The third experiment (n=20) analyzed the effect of static passive stretching of peroneus longus and peroneus brevis muscles on the ankle sprain simulation. During the locomotion protocols the injured side showed late peaks and an increase of the GRF impulses. The instable ankle showed an increase of dorsiflexion during the initial phase of gait and an increase of eversion during running. The instable ankle also showed a decrease of inversion and an increase of dorsiflexion during jumping. These strategies represent an attempt to improve the joint dynamic stability. There was an increase in sagittal and frontal angular displacement, suggesting more range of motion as well as more stress in the passive structures that are responsible for stabilization in the injured ankle. During muscular fatigue, after an ankle sprain simulation, subjects with healthy joints increase the joint stiffness and the intensity of the ankle eversion muscles activation, before the intervention, differently from subjects with chronic instability. The peroneus longus and brevis stretching exercise followed by the ankle sprain simulation caused a delay on the motor response and a decrease in the activation intensity. The strategies developed by the subjects with chronic instability can be related to the cause and/or the consequence of the dysfunction. The muscular fatigue changes the development of strategies of protection and the stretching exercise can weaken the dynamic stability of the joint

Abstract available in the Journal of Strength and Conditioning Research

No description available.

La parésie spastique est souvent envisagée comme une atteinte de la commande motrice, comportant une parésie de l’agoniste et une hyperactivité de l’antagoniste. Cependant, une seconde affection d’ordre musculaire - la myopathie spastique, apparait rapidement, pendant la phase aigüe après la lésion. L’hypomobilisation en position courte de certains muscles dans le contexte d’une parésie des muscles opposés s’accompagne d’une perte de leur tension longitudinale, première étape d’une cascade de transformations génétiques, structurelles, biomécaniques puis physiologiques des muscles hypomobilisés, incluant entre autres une perte de leur extensibilité et de leur longueur. Aux stades subaigu puis chronique du syndrome, les affections neurologique et musculaire coexistent, et semblent s’entretenir mutuellement.Sur le plan physiopathologique, ce travail de recherche s’est d’abord intéressé à ces intrications entre les affections neurologique et musculaire, et à la part de responsabilité potentielle de la myopathie spastique dans la fonction active. Ce premier travail a montré que le degré d’hypoextensibilité musculaire d’un antagoniste, au-delà d’un certain seuil, est corrélé au degré de perturbation de la commande motrice dirigée sur l’agoniste. La chronologie des différents événements établie dans la littérature, avec des anomalies histologiques musculaires qui apparaissent toujours avant les premières manifestions d’hyperactivité motoneuronale, amène à suggérer une responsabilité causale de la maladie du muscle dans une partie des perturbations ultérieures de la commande neuronale descendante. Ce rôle probablement essentiel de la maladie musculaire au sein de la parésie spastique doit inciter le clinicien à orienter une part significative de son traitement vers une stimulation optimale de la plasticité musculaire pour tenter de prévenir ou d’inverser le processus de myopathie spastique.Si l’étirement est depuis très longtemps une technique courante, sa capacité à augmenter durablement l’extensibilité musculaire est aujourd’hui controversée, même si ses effets à long terme, i.e. au-delà de six mois d’application quotidienne, n’ont pas été explorés.La deuxième partie, thérapeutique, de ce travail a donc été l’étude des effets à long terme d’un programme quotidien d’auto-étirements de haute intensité au sein de la méthode des Contrats d’Autorééducation Guidée, pendant un an ou plus. Il a d’abord été rétrospectivement montré que ce programme avait permis, sur trois années de suivi de sujets parétiques, une amélioration progressive importante de l’extensibilité musculaire mesurée cliniquement. Un essai randomisé contrôlé contre la kinésithérapie conventionnelle avec mesures échographiques de paramètres structuraux des muscles étirés a ensuite établi que l’application de ce programme durant un an chez des sujets atteints d’hémiparésie chronique sur AVC générait une augmentation de la longueur fasciculaire des muscles fléchisseurs plantaires, parallèlement à une amélioration de la fonction active, de façon nettement plus importante que la thérapie conventionnelle.L’ensemble de ces résultats doit participer à une meilleure prise en compte des altérations passives structurelles évolutives du muscle comme une entité nosologique, la myopathie spastique, méritant un traitement spécifique au sein de la parésie spastique, afin de limiter ses interactions avec la maladie neurologique et de réduire les déficits fonctionnels. La pratique quotidienne de postures d’auto-étirement à haute intensité, guidée par un thérapeute et auto-documentée par le patient sur un registre, peut être prescrite et réalisée sur le long terme, afin de traiter la myopathie spastique. / Spastic paresis is often understood as a neurologic disorder of the motor command that includes agonist paresis and antagonist overactivity. However, a second disorder, involving the muscle and named spastic myopathy, appears rapidly during the acute phase after the lesion. Hypo-mobilization in shortened position of some muscles of the paretic limbs, in the context of paresis of their antagonists, will reduce their longitudinal tension, which acts as the first event of a cascade of transformations involving genetic, structural, biomechanical, and then physiological mechanisms, leading to loss of muscle extensibility and length. At the subacute and chronic stages of this syndrome, the neurological and the muscular disorders coexist, seemingly feeding on each other.From a pathophysiological point of view, this research work started by exploring the entanglements between the neurological and muscular disorders, and the potential responsibility of spastic myopathy in the impairment of active function. The first study demonstrated that the loss of muscle extensibility in antagonists, when above a certain threshold, correlates with the degree of disturbance of the motor command directed to the agonist. The chronology of events established in the literature, with histological muscle abnormalities emerging always before the first expressions of motoneuronal overactivity, suggests a causal role of the muscle disorder in a part of the descending command disorder. The crucial role of the muscle disorder in the syndrome of spastic paresis should encourage clinicians to direct treatment towards techniques to stimulate muscle plasticity.Despite the classic use of muscle stretching in daily practice, its potential to increase muscle extensibility remains a subject of controversy, even though its long-term effects, i.e. over six months of daily implementation, have not been investigated. The second part of this work was thus therapeutic. We retrospectively explored the long-term effects of a daily, high load self-stretching programme within the Guided Self-rehabilitation Contract method, for at least a year. This work showed that this programme, applied over three years in paretic subjects, was increasingly associated with major gains in clinical muscle extensibility. A randomized controlled trial against conventional therapy, which used ultrasound exploration of structural parameters in the stretched muscles, demonstrated that this programme, applied over one year in subjects with stroke-induced chronic hemiparesis, enabled greater increase in plantar flexor fascicle length and active function improvement than conventional therapy.Taken together, these results will contribute to enhancing the knowledge about the evolving structural and mechanical muscle changes in spastic paresis, as a pathologic entity, spastic myopathy. Spastic myopathy needs to be specifically addressed, as it interacts with the neurological disorder and worsens functional impairment. Daily postures of high load self-stretch, guided by the therapist and self-monitored on a diary, should be prescribed and practiced over the long term, in order to treat spastic myopathy in subjects with spastic paresis.