INTRODUÇÃO: A dor lombar é um importante problema de saúde pública presente em todas as nações industrializadas, afetando 70% a 80% da população adulta em algum momento da vida, com predileção por adultos jovens, em fase economicamente ativa. Está em segundo lugar entre as causas de afastamento do trabalho. Há uma grande variedade de protocolos cinesioterapêuticos para a dor lombar, contudo não há evidências sobre qual o tipo de exercício mais efetivo. OBJETIVO: Comparar a eficácia dos exercícios de estabilização segmentar, alongamento lombar e fortalecimento da musculatura abdominal e do tronco na dor, capacidade funcional e capacidade de ativação do músculo TrA de indivíduos lombálgicos crônicos. METODOLOGIA: Participaram da pesquisa 45 pacientes randomizados em três grupos que realizaram exercícios para músculos específicos: Grupo Estabilização Segmentar (ES) (transverso do abdome e multífido lombar) (n=15, idade 42,02 ± 8,15), Grupo Fortalecimento Superficial (FS) (reto abdominal, oblíquos interno e externo e eretores da coluna) (n=15, idade 41,71±6,41) e Grupo Alongamento (AL) (eretores da coluna, tecidos moles posteriores e isquiotibiais) (n=15, idade 41,53 ± 4,41). Foram avaliados quanto à dor (Escala Visual Analógica e Questionário McGill de Dor), capacidade funcional (Índice de Incapacidade de Oswestry) e capacidade recrutamento do músculo TrA (Unidade de Biofeedback Pressórico-UBP). Os grupos foram tratados em duas sessões semanais com duração de 30 minutos, por seis semanas. Cada paciente foi avaliado antes e após o tratamento. Foi utilizado o teste Anova com um fator e o teste Post Hoc de Tukey para realizar comparações intra e entre grupos. Foi adotado um nível de significância de 5%. RESULTADOS: Para as variáveis dor e capacidade funcional os três tratamentos mostraram-se eficazes (p<0,001). Na comparação entre os grupos, o ES obteve os maiores ganhos em todas as variáveis (p<0,001) e na ativação do TrA, os ganhos relativos foram 48,32%, 6,56% e -5,11% nos grupos ES, AL e FS, respectivamente. CONCLUSÃO: Os três grupos apresentaram melhora na intensidade da dor e capacidade funcional, com ganhos médios maiores para o grupo ES e superiores na ativação do TrA. Não foi observada melhora nos grupos AL e FS na capacidade de ativação do músculo TrA. / INTRODUCTON: Low back pain is a health important problem present in all industrialized countries, affecting 70% to 80% of adult population in some moment of life, most frequently in young adults, in economically active phase. It is in second place among the causes of work absenteeism. Although a number of exercises for low back pain is great, there are no evidence of what kind of exercise is more effective. OBJECTIVE: to contrast the efficacy of segmental stabilization, lumbar stretching and trunk and abdominal strengthening exercises on pain, functional disability and the recruitment TrA muscle of patients with chronic low back pain. METHODS: Forty-five patients were randomized into three groups namely: Segmental stabilization group (ES)(transversus abdominis and lumbar multifidus) (n=15, mean age 42,02 ± 8,15), superficial strengthening group (FS)(rectus abdominis, oblique abdominal muscles and erector spinae muscles) (n=15, mean age 41,71±6,41) and stretching group (AL) (erector spinae, posterior connective tissues and ischiotibials muscles) (n=15 mean age 41,53 ± 4,41). Patients attended two weekly sessions during six weeks and were evaluated for pain (visual analogue scale and McGill Pain Questionnaire), functional disability (Oswestry disability index), and ability to contract the TrA (Pressure biofeedback unit) before and after the treatment. The treatment program consisted of 30 minutes sessions. The Anova oneway and Tukey´s Post Hoc were used to compare groups. The significance level adopted was 5%. RESULTS: Significant pain relief and functional disability improvements were observed after treatment in three groups (p<0,001). The segmental stabilization group showed greater gains in all variables (p<0,001) and in TrA activation, the relative gains were 48,32%, 6,56% and -5,11%, in ES, AL and FS groups, respectively. CONCLUSION: The three groups of exercise improved pain and functional disabilities, and the ES group was better in the ability to recruit TrA muscle (PBU). In AL and FS groups was not observed improvement in TrA muscle.

Technology scaling has increased the transistor's susceptibility to process variations in nanometer very large scale integrated (VLSI) circuits. The effects of such variations are having a huge impact on performance and hence the timing yield of the integrated circuits. The circuit optimization objectives namely power, area, and delay are highly correlated and conflicting in nature. The inception of variations in process parameters have made their relationship intricate and more difficult to optimize. Traditional deterministic methods ignoring variation effects negatively impacts timing yield. A pessimistic worst case consideration of variations, on the other hand, can lead to severe over design. In this context, there is a strong need for re-invention of circuit optimization methods with a statistical perspective. In this dissertation, we model and develop novel variation aware solutions for circuit optimization methods such as gate sizing, timing based placement and buffer insertion. The uncertainty due to process variations is modeled using interval valued fuzzy numbers and a fuzzy programming based optimization is proposed to improve circuit yield without significant over design. In addition to the statistical optimization methods, we have proposed a novel technique that dynamically detects and creates the slack needed to accommodate the delay due to variations. The variation aware gate sizing technique is formulated as a fuzzy linear program and the uncertainty in delay due to process variations is modeled using fuzzy membership functions. The timing based placement technique, on the other hand, due to its quadratic dependence on wire length is modeled as nonlinear programming problem. The variations in timing based placement are modeled as fuzzy numbers in the fuzzy formulation and as chance constraints in the stochastic formulation. Further, we have proposed a piece-wise linear formulation for the variation aware buffer insertion and driver sizing (BIDS) problem. The BIDS problem is solved at the logic level, with look-up table based approximation of net lengths for early variation awareness.In the context of dynamic variation compensation, a delay detection circuit is used to identify the uncertainty in critical path delay. The delay detection circuit controls the instance of data capture in critical path memory flops to avoid a timing failure in the presence of variations. In summary, the various formulation and solution techniques developed in this dissertation achieve significantly better optimization compared to related works in the literature. The proposed methods have been rigorously tested on medium and large sized benchmarks to establish the validity and efficacy of the solution techniques.

Performance of a series of eccentric contractions produces adverse effects including muscle weakness, delayed onset muscle soreness (DOMS), fluid accumulation and decreased muscle function. The repeated bout effect is a physiological adaptation observed when a single-bout of eccentric exercise protects against muscle damage from subsequent eccentric bouts. Similar to the repeated bout effect, increases in flexibility have been linked to attenuations in acute muscle damage, muscle fatigue and strength loss after eccentric exercise. Purpose: The purpose of this study was to examine the muscle physiological responses to eccentric strength training after first priming the muscles with either a period of static flexibility training or a single intense bout of eccentric exercise performed weeks earlier; and compare these to the responses from eccentric strength training when no prior intervention is administered. Methods: Twenty-five participants were randomly assigned to a flexibility (F) (n=8), a single-bout (SB) (n=9), or a control (C) (n=8) group. The design consisted of two 4-week phases; 1) priming intervention, 2) eccentric training. The priming intervention included static stretching (3x/week; 30mins/day) (F), a single-bout of eccentric exercise (SB) or no priming intervention (C). All groups proceeded to complete eccentric training of the knee flexors using isotonic contractions (%load progressively increased over training period) on a dynamometer following the priming intervention phase. Testing was completed at baseline, post-priming intervention and post-eccentric training, in conjunction with data being collected during the acute eccentric training phase (0hr, 24hr, 48hr; post-bout 1 and 4). Dependent measures included muscle thickness, isometric maximal voluntary contraction (MVC), eccentric and concentric MVC, optimal angle, active range of motion (ROM), passive ROM, maximal power, electromyography (EMG) and delayed onset muscle soreness (DOMS). Results: Acute data during the eccentric training phase revealed a significant reduction in DOMS for both the F and SB groups compared to the C following the first bout of eccentric exercise (p<0.05). The F also had reduced soreness in comparison to both the SB and C post fourth bout of eccentric exercise (p<0.05). The F group demonstrated attenuated loss in isometric strength (post fourth bout) and maximal power (post first bout) during eccentric training compared to the C group (p<0.05). However, there was no significant difference between groups across all dependent variables following the eccentric training phase. Conclusion: This is the first study to directly compare the protective effects observed with static flexibility training to that of a single-bout of eccentric exercise throughout a subsequent eccentric training regime. Although differences in muscle soreness, strength and maximal power occurred during the acute stages of eccentric training, there appeared to be no significant advantage of either protective priming method at the end of eccentric training.

Juosmens skausmai – aktuali nūdienos sportininkų problema. Daugelyje sporto šakų yra aptartos šių skausmų priežastys ir išvengimo bei šalinimo problemos. Tačiau apie bokse patiriamus nugaros skausmus nėra plačiai išnagrinėta, bei atlikta pakankamai tyrimų. Skausmo priežasties bei prevencijos nagrinėjimas sportuojant boksą leistų sumažinti skausmų tikimybę ir pilnavertį sportininko ruošimąsi. Planuojant tyrimą buvo suformuluotas probleminis klausimas: ar taikant tempimo pratimus galima pagerinti boksininkų stuburo paslankumą ir išvengti ar sumažinti juosmeninės stuburo dalies skausmus. Darbo tikslas yra nustatyti tempimo pratimų poveikį boksininkų liemens raumenų ištvermei, skausmui ir stuburo paslankumui. Tyrimo tikslui pasiekti iškelti uždaviniai: 1. Įvertinti juosmeninės stuburo dalies skausmo pasireiškimą ir stiprumą tiriamojoje imtyje. 2. Įvertinti tiriamųjų, kurie jautė juosmeninės stuburo dalies skausmus, skausmo pokyčius, liemens raumenų statinę ištvermę, stuburo paslankumą ir pečių lanko simetriškumą, prieš ir po techninio pasiruošimo treniruočių ciklo, kuriame buvo taikyti tempimo pratimai. 3. Įvertinti tiriamųjų, kurie nejautė juosmeninės stuburo dalies skausmų, skausmo pokyčius, liemens raumenų statinę ištvermę, stuburo paslankumą ir pečių lanko simetriškumą, prieš ir po techninio pasiruošimo treniruočių ciklo, kuriame nebuvo taikyti tempimo pratimai. 4. Nustatyti koreliaciją tarp: nugaros raumenų ištvermės ir juosmens skausmo I ir II testavimo metu... [toliau žr. visą tekstą] / A lumbar pain is a relevant problem of modern athletes. The causes of these pains and the ways of avoidance and prevention of them have been analysed in many sports branches. In boxing, however, not much has been done regarding spine pains. The study on the cause of pain and its prevention when exercising boxing would enable to reduce the possibility of pain and ensure full range preparation of an athlete. Before initiating the study, a problem question was formulated: is it possible to improve the mobility of the spine and avoid or, at least, diminish low back pains by applying stretching exercises in the boxing sport branch. The aim of the paper is to test stretching exercises effect, of boxers trunk muscles endurance, low back pain prevention and spine mobility. The following objectives have been set to achieve the aim of the study: 1. To asses the lumbar pain and pain power of investigatives. 2. To assess investigatives, who felt low back pain, pain alteration, back muscle endurance, spine mobility and shoulders symmetry, before and after technical readiness of training, whereat was applied streching exercises. 3. To asses investigatives, who didn‘t felt low back pain, pain alteration, back muscle endurance, spine mobility and shoulders symmetry, before and after technical readiness of training, whereat the streching exercises was not applied. 4. To evaluate the correlation between: back muscle endurance with lumbar pains, on I and II testing, side mobility... [to full text]

The aims of the thesis were (i) to investigate the impact of repetitive low-intensity work exposure on proprioception and (ii) to examine effects of muscle stretching (especially sensory effects and effects on muscle nociception) and to relate its application to the prevention, alleviation and/or treatment of work-related neuromuscular disorders. The effects of low-intensity repetitive work on the shoulder proprioception were tested in healthy subjects. The effect of working time on the retention of subjective fatigue and their relation to changes in proprioception, and the immediate effect of stretching on shoulder proprioception were investigated. A new method to test the stretchability of the rectus femoris muscle was investigated for reliability and validity and used to assess the effects of a two-week stretching regimen on range of motion and on subjective stretch sensation. Finally, the interactions between innocuous muscle stretch and nociceptive chemical stimulation on discharge behavior of nociceptive dorsal horn neurons in the feline spinal cord were explored. The main findings were as follows: 1) The repetitive low-intensity work to fatigue diminished the shoulder proprioception; the working time as well as the retention of subjective fatigue were partly related to the extent of changed proprioception. 2) There was no effect of acute muscle stretching on the proprioception. 3) The new method for testing muscle stretchability proved valid and reliable. A two-week stretching regimen increased the tolerance to stretch torque, but the range of motion remained unchanged. 4) Half of the nociceptive dorsal horn neurons that responded to close arterial injections of bradykinin were modulated by muscle stretching applied directly after the injections. Altogether, the results give credence to the hypothesis of an involvement of sensory information distortion due to repetitive low-intensity work exposure in the development of work-related neuromuscular disorders. Increased tolerance to stretch torque may be an important mechanism in explaining improvements following stretch treatment. The spinal interactions between innocuous stretch and nociceptive muscle afferent inputs indicate a possible mechanism involved in stretching-induced pain alleviation.

Nous étudions le comportement de gels, transitoires auto-assemblés et réticulés permanents, soumis à des contraintes mécaniques extrêmes. D'une part, nous étudions la déformation biaxiale de nappes libres produites par impact d'une goutte liquide (Newtonienne ou viscoélastique) ou d’une perle de gel polymère sur des surfaces solides dans des conditions de dissipation minimale, obtenues soit avec une petite cible solide, soit avec une surface répulsive. Lors de l'impact, la goutte ou perle est transformée en une nappe mince qui s’étend et se rétracte sous l’action de forces de rappel élastiques. Pour les fluides viscoélastiques avec un temps de relaxation plus petit que la durée de vie typique de la nappe, la dynamique de la nappe viscoélastique est similaire à d’un liquide visqueux Newtonien de même viscosité. L’expansion maximale de la nappe diminue avec la viscosité et est modélisée quantitativement en utilisant un bilan énergétique entre l'inertie, la tension superficielle et la dissipation du cisaillement visqueux sur la cible solide, qui peut être prise en compte en mesurant une vitesse effective de la nappe à temps court, en sortie de cible. Nous montrons en outre que la dissipation visqueuse peut être sensiblement éliminée en utilisant une surface solide sur la base d'un effet de Leidenfrost inverse. Les expériences effectuées à l'aide de perles élastiques de modules élastiques variables, de gouttes liquides de tensions superficielles variables et de gouttes viscoélastiques révèlent un comportement universel pour l’expansion maximale de la nappe avec la vitesse d'impact, avec une dynamique analogue à celle d'un système ressort-masse conventionnel. Nous montrons en outre que, pour les gouttes qui impactent une petite cible solide, une description similaire peut être utilisée une fois que la dissipation visqueuse est prise en compte en remplaçant la vitesse d'impact par la vitesse effective. Un autre comportement fascinant des fluides viscoélastiques est l’expansion hétérogène de la nappe associée à l’apparition de fissures, révélant la nature élastique du fluide viscoélastique. D’autre part, nous étudions la déformation uniaxiale et la facture de filaments de doubles réseaux transitoires en couplant rhéométrie extensionnelle et imagerie rapide des filaments étirés. Nous établissons un diagramme d'état qui délimite le régime de du filament, lorsqu'il est étiré à un taux supérieur à l'inverse du temps de relaxation du plus lent des deux réseaux. Nous démontrons quantitativement que les processus de dissipation ne sont pas pertinents dans nos conditions expérimentales et que, suivant la densité des nœuds dans les réseaux, la rupture se produit dans le régime élastique linéaire, ou non linéaire précédé d'une augmentation considérable de la viscosité extensionnelle. L'analyse des profils d'ouverture des fissures indique, pour des réseaux faiblement connectés, des écarts par rapport à une forme parabolique en pointe de fissure, caractéristique d’une fracture fragile en régime linéaire. Nous montrons une corrélation directe entre l'amplitude de la déviation de la forme parabolique et le caractère non linéaire de la déformation élastique. / We investigate the behavior of transient self-assembled and permanently crosslinked gels subjected to extreme mechanical stresses. On the one hand, we study the dynamics of freely expanding sheets produced by impacting a (Newtonian or viscoelastic) liquid drop or a bead of polymeric gel on solid surfaces in minimal dissipation conditions, achieved using either a small solid target or a repellent surface. Upon impact, the drop or bead is transformed into a thin sheet that expands and retracts due to elasticity. For viscoelastic fluids with a relaxation time smaller than the typical lifetime of the sheet, the dynamics of the viscoelastic sheet is similar to that of Newtonian liquids with equal viscosity. The maximal expansion of the sheet decreases with the viscosity and is quantitatively modeled using an energy balance between inertia, surface tension and viscous shear dissipation on the solid target that can be accounted by measuring an effective velocity of the expanding sheet at short time scale. We further show that the shear dissipation can be substantially eliminated by performing impact experiments on a solid surface based on an inverse Leidenfrost effect. Experiments performed using elastic beads of various elastic moduli, viscoelastic or liquid drops of various surface tensions reveal a universal scaling behavior of the maximum expansion with the impact velocity, with a dynamics that mimics that of a conventional spring-mass system. We furthermore show that, for drops impacting a solid target, a similar scaling holds once the viscous dissipation is accounted by replacing the impact velocity with the effective velocity. Another fascinating behavior of viscoelastic fluids is a heterogeneous expansion of the sheet with the occurrence of cracks, revealing the elastic nature of the viscoelastic fluid. On the other hand, we study the uniaxial deformation and the fracture of reversible double transient networks by coupling extensional rheology to fast imaging. We provide a state diagram that delineates the regime of fracture without necking of the filament, when it is stretched at a rate larger than the inverse of the slowest relaxation time of the networks. We quantitatively demonstrate that dissipation processes are not relevant in our experimental conditions and that, depending on the density of nodes in the networks, fracture occurs in the linear elastic regime, or in a non-linear elastic regime preceded by a considerable strain hardening. In addition, analysis of the crack opening profiles indicates, for weakly connected networks, deviations from a parabolic shape close to the crack tip, which is expected for the linear elasticity of a brittle fracture. We demonstrate a direct correlation between the amplitude of the deviation from the parabolic shape and the amount of non-linear elasticity.

THE INFLUENCE OF STRETCHING EXERCISES ON THE RANGE OF JOINT FLEXIBILITY IN STUDENTS AT JAN EVANGELISTA PURKYNĚ UNIVERSITY IN ÚSTÍ NAD LABEM The dissertation evaluates the influence of stretching exercises on the range of joint flexibility in students of the study programme Physical Education and Sport at Jan Evangelista Purkyně University in Ústí nad Labem. In total, 128 students aged 21 - 25 (78 women, 50 men) enrolled in the subject Basic Gymnastics took part in the experiment, conducted in the period from February to May of the academic year 2008/2009. Of these, 59 students were excluded by a physiotherapist - i.e. hypermobile men and hypermobile women as well as women with normal flexibility (excluded purposefully) subject to the results of the Thomayer test. In total, data from 39 men and 30 women were used. From April 2009, over a period of six weeks (before the end of the summer term tuition), an intervention flexibility programme including the Anderson static stretching method and the PNF stretching method by Sölveborn were applied for the research file. To evaluate the level of joint flexibility, the Sit and Reach Test and credit exercise to estimate joint flexibility were used. In a controlled interview, out-of-school activities were analysed, which contained stretching exercises with a...

Made available in DSpace on 2016-06-02T20:18:23Z (GMT). No. of bitstreams: 1 5995.pdf: 2869208 bytes, checksum: 78818b61943b25fd2cc3f8d00a47f406 (MD5) Previous issue date: 2013-06-06 / The anatomical alterations of spine have been researched in experimental and clinical studies. The present study focused the analysis on the three aspects. The scoliosis and the alterations on the metabolic profile of the paravertebral and pectoral muscles (study I), the scoliosis and stretching influence in the plasma citocines concentration (study II) and the status of cardiac autonomic function front the scoliosis implantation (study III). The three studies were performed with male rats, which were divided into different experimental groups, with a total n of 68 animals. For the scoliosis induction were applied a non-invasive model composed by vests made of polyvinyl chloride (PVC). All data were expressed as mean ± epm. For the statistical analysis the Kolmogorov-Smirinov test was applied to investigate the normality of the data, whereas studies I and II were followed by the variance analysis ANOVA and Tukey post hoc (p<0,05), in the study III were used the Student-t test or the sum of rank in the Mann-Whitney test (p<0,05). In the first study were applied vests to the scoliotic group since the initial growth phase (post weaning) until the sixth week of growth, however in the studies II and III the vests application went up to the twelfth week. To the achievement of the first study the rats were divided into 2 experimental groups with n=6: control (C) and scoliotic (S). The outcomes from this study showed a reduction on the relation total protein/DNA, in the glycogen content and in the total weight of the scoliotic animals. This study established a homeostatic impairment of the pectoral and paravertebral muscles during the scoliosis induction process. In the second study the animals were distributed into 4 groups with n=8: control (C), stretched (S), scoliotic (SG) and stretched scoliotic (SS). The stretching consisted in 3 series of 30 seconds with 10 seconds of interval among the series. The results revealed an important increase in the concentration of IL-2, IL-6 and e TNF-&#945; in the scoliotic group, whereas the intervention with stretching exercises could achieve a decrease of 4, 9 and 6% respectively on the concentration increase. These results suggest that the proposed model used to induce the scoliosis lead to a muscular disuse and the stretching has showed to be effective to minimize the deriving consequences of this disuse. In the third study the animals were divided into 2 groups again, control group (C, n=12) and scoliosis group (S, n=12). On this study the attention referred to possible alterations in the cardiovascular autonomic control system. Evaluations of heart rate variability, cardiac autonomic tonus and cardiac baroreflex sensitivity. From these results was possible to certify that scoliosis causes an alteration in the autonomic control, being that the scoliotic group presented best sympathetic modulation, greater vagal tone and greater cardiac baroreflex sensitivity. The outcomes suggest that scoliosis promote alterations in the autonomic function of the cardiac system. In general, the results from this study demonstrated that the scoliotic animals have smaller glycogen reserves and lower ratios of total protein/DNA; higher concentration of the citocines IL-2, IL-6 and TNF-&#945;, while the scoliotic and stretched rats have lower concentrations from the same citocines; referring to the autonomic modulation the scoliosis led to a higher total variance, greater sympathetic cardiac modulation, greater vagal tono and best baroreflex sensitivity proving a better condition in the cardiovascular autonomic function through the most part of the evaluated items in the scoliotic rats. / As alterações anatômicas da coluna vertebral têm sido investigadas em estudos clínicos e experimentais. O presente trabalho concentrou suas análises em três vertentes: A escoliose e suas alterações no perfil metabólico da musculatura paravertebral e peitorais (estudo I), as influências da escoliose e do exercício de alongamento sobre a concentração de citocinas plasmáticas (estudo II) e o status da função autonômica cardiovascular frente à implantação da escoliose (estudo III). Os três estudos foram realizados com ratos machos divididos em diferentes grupos experimentais, com n total de 68 animais. Para a implantação da escoliose foi utilizado um modelo não invasivo constituído por um colete de filme de policloreto de vinil (PVC). Os dados foram apresentados em média ±epm. Para a avaliação estatística os dados foram submetidos ao teste de normalidade Kolmogorov-Smirnov, sendo que nos estudos I e II foi seguido da análise de variância ANOVA e post hoc de Tukey (p<0,05), no estudo III teste t-Student ou pela soma dos ranks no teste de Mann-Whitney (p<0,05). No primeiro estudo o grupo escoliótico recebeu a aplicação do colete desde as fases iniciais de crescimento (pós-desmame) até a sexta semana de crescimento, e nos estudos II e III a aplicação do colete foi até a décima segunda semana. Para a realização do primeiro estudo os animais foram distribuídos em 2 grupos experimentais de n=6: controle (C) e escoliótico (E). Os resultados desse estudo revelaram redução na relação proteína total/DNA, no conteúdo de glicogênio e no peso total dos animais escolióticos. Com esse estudo foi constatado comprometimento homeostático de músculos peitorais e paravertebrais durante o processo de indução de escoliose. No segundo estudo os animais foram distribuídos em quatro grupos de n=8: controle (C), alongado (A), escoliótico (E) e escoliótico alongado (EA). O alongamento consistiu de 3 séries de 30 segundos com intervalos de 10 segundos entre as séries. Os resultados revelaram importante aumento das concentrações de IL-2, IL-6 e TNF-&#945; no grupo escoliótico, por outro lado a intervenção com exercício de alongamento foi capaz de reduzir em 4, 9 e 6% respectivamente esse aumento. Esse resultado sugere que a indução de escoliose com o modelo proposto promove desuso muscular e o alongamento se mostrou capaz de minimizar os efeitos decorrentes desse desuso. No terceiro estudo os animais foram divididos novamente em 2 grupos experimentais, grupo controle (C, n=12) e grupo escoliose (E, n=12). Nesse estudo a atenção foi voltada para possíveis alterações no sistema de controle autonômico cardiovascular. Foram realizadas avaliações da variabilidade da frequência cardíaca, do tônus autonômico cardíaco e da sensibilidade barorreflexa cardíaca. Com os resultados foi possível constatar que a escoliose promove uma alteração no controle autonômico, de forma que o grupo escoliótico apresenta maior modulação simpática, maior tônus vagal e maior sensibilidade baroreflexa cardíaca. Os dados sugerem que a escoliose promove alterações na função autonômica do sistema cardiovascular. No geral, os resultados desse trabalho revelam que os animais escolióticos possuem menores reservas glicogênica e menor relação proteína total/DNA; maiores concentrações das citocinas IL-2, IL-6 e TNF-&#945;, ao passo que os ratos escolióticos e alongados possuem menor concentração das mesmas citocinas; quanto a modulação autonômica cardiovascular a escoliose levou a maior variância total maior modulação simpática cardíaca, maior tônus vagal e maior sensibilidade baroreflexa mostrando melhor condição da função autonômica cardiovascular pela maioria dos índices avaliados nos ratos escolióticos.

Made available in DSpace on 2016-06-02T20:19:04Z (GMT). No. of bitstreams: 1 DissLHB.pdf: 2237464 bytes, checksum: a9f2e45dc713b4d16aefdcfdf7b78613 (MD5) Previous issue date: 2005-02-28 / Universidade Federal de Minas Gerais / The relation between flexibility alterations and muscular torque posstretching is not so exploited in literature. There are many stretching techniques and posture used in clinics and sportive activities. The technique of eccentric active stretching in a standing posture, with weight unloading in the stretched limb, is one of them. Thus, a better knowledge of the alterations caused after its application will provide scientific support for its usage. Objective: To evaluate the effects of an eccentric active stretching program of the knee flexor muscles in the standing posture on the evaluated limb on: knee extension ROM, passive torque of knee flexor muscles and isometric and isokinetic concentric and eccentric torque of flexor and extensor muscles of the knee. Methodology: 34 healthy and sedentary volunteers, both genders (34,42 ± 9,3 years) were evaluated. All of them had 20° or more knee flexor muscles shortening. The stretching program was performed twice a week, for four weeks and consisted of 7 consecutive repetitions of 1 min each one with a 30s rest between them. Knee ROM and knee torque were evaluated using an Isokinetic Dynamometer before and after four weeks of intervention. The passive torque and knee ROM were measured passively, while the isometric, concentric and eccentric torque of the flexor and extensor of the knee were measured through maximal voluntary contractions (speeds 30°/s, 60°/s). Results: There was an increase in the knee extensor ROM from 53,7 ± 13° to 30,1 ± 16° (p = 0,0001). No alteration occurred in the passive torque (from 11,2 ± 3N to 10,6 ± 3N; p = 0,09). The isometric extensor and flexor torque increased from 68 ± 67,8N to 187,58 ± 73,5N (p = 0,006) and from 89,68 ± 32,62N to 93,87 ± 33,12N (p = 0,01), respectively. There was a gain of knee extensor concentric torque at 60°/s from 144,44 ± 51,6N to 151,57 ± 58,2N (p = 0,02) and knee extensor eccentric torque at 30°/s from 175,4 ± 71,6N to 189,9 ± 73,8N (p = 0,01). There was an improvement in the flexor eccentric and concentric torque at 30º /s (from 100,3 ± 34,2N to 105,63 ± 35N; p = 0,02 and from 90,7 ± 31,7N to 96,7 ± 31,8N; p = 0,001, respectively). Conclusions: The eccentric active stretching program of the knee flexor muscles in a standing posture was effective to increase knee extension ROM, improving flexibility in the knee flexor muscles, although there was no change in the passive torque. It also improved the isometric and isokinetic peak torque from the muscle group submitted to the stretching and its antagonist group. / A relação entre alterações na flexibilidade e torque muscular pósalongamentos tem sido pouco explorada pela literatura. São inúmeras as técnicas e posturas de alongamento sendo utilizadas tanto nas clínicas quanto em atividades esportivas. A técnica de alongamento ativo excêntrico realizada na postura em pé, com descarga de peso no membro alongado, estão entre elas. Sendo assim, o maior conhecimento das alterações geradas após sua aplicação, dará suporte para que sejam executadas mediante evidências científicas que comprovem sua eficácia. Objetivo: foi avaliar o efeito de um programa de alongamento ativo excêntrico dos músculos flexores do joelho na postura em pé com descarga de peso no membro avaliado, sobre as variáveis: Amplitude de movimento (AM) de extensão do joelho, torque passivo dos músculos flexores do joelho e torque isométrico e isocinético dos músculos extensores e flexores do joelho. Metodologia: foram selecionados 34 voluntários, de ambos os sexos, com idade de 34,42 ± 9,3 anos, sedentários, saudáveis e com, no mínimo, 20º de encurtamento dos músculos flexores do joelho. Todas as variáveis estudadas foram avaliadas pré e pós-programa de alongamento, em um Dinamômetro Isocinético (Biodex Multi-joint System 3). O programa de alongamento dos músculos flexores do joelho foi realizado duas vezes por semana durante quatro semanas. Cada sessão de alongamento consistiu de sete repetições de 1min de alongamento intercaladas com 30 s de repouso. A avaliação da Amplitude de movimento e do torque passivo foram realizados passivamente. O toque isométrico e isocinético concêntrico e excêntrico dos músculos extensores e flexores do joelho, foram testados por meio de contrações voluntárias máximas Contração Voluntária Máxima (CVM) nas velocidades a 30º/s e 60º/s. Resultados: demonstraram aumento na amplitude de movimento de extensão do joelho de 53,7 ± 13° para 30,1 ± 16° (p = 0,0001). O valor do torque passivo não alterou significativamente (11,2 ± 3N para 10,6 ± 3N; p = 0,09). O torque isométrico extensor aumentou de 178,68 ± 67,8N para 187,58 ± 73,5N (p = 0,006) e o flexor de 89,68 ± 32,62N para 93,87 ± 33,12N (p = 0,01). O torque isocinético concêntrico dos músculos extensores aumentou a 60°/s de 144,44 ± 51,6 N para 151,57 ± 58,2N; (p = 0,02) e o excêntrico a 30°/s de 175,4 ± 71,6 N para 189,9 ± 73,8 N; (p = 0,01). O torque isocinético tanto excêntrico quanto concêntrico dos músculos flexores do joelho aumentou a 30°/s (de 100,3 ± 34,2 N para 105,63 ± 35 N; p = 0,01 e de 90,7 ± 31,7 N para 96,7 ± 31,8 N; p = 0,001, respectivamente). Conclusão: o programa de alongamento ativo excêntrico dos músculos flexores do joelho, realizado na postura em pé, foi efetivo em aumentar a amplitude de movimento de extensão do joelho, sendo assim aumentou a flexibilidade dos flexores do joelho, embora não tenha constatado alteração no torque passivo. Também se mostrou eficaz em aumentar o pico de torque isométrico e isocinético tanto do grupo muscular submetido ao alongamento quanto do seu antagonista.

Made available in DSpace on 2016-06-02T20:19:25Z (GMT). No. of bitstreams: 1 598.pdf: 612982 bytes, checksum: 1ec87d8ea6133011e61dbd36abec0293 (MD5) Previous issue date: 2005-02-25 / Universidade Federal de Sao Carlos / Objective: The aim of this study is to evaluate the articular cartilage alterations of rat ankles, after applying unilateral cyclic passive muscle stretching protocol for three weeks in previously immobilized rats. Materials and Methods: Twenty-two male albino rats (280+25.4g) divided into four groups: I-immobilized (n=6), IS-immobilized and stretched (n=5), S-stretched (n=6) and C-control (n=5), were used in this experiment. In the immobilization protocol (groups I and IS) the left ankle joints were immobilized in full plantar flexion and this immobilization device was kept on for four weeks. The animal was allowed free cage activity with the device. In the muscle stretching protocol (groups IS and S) the left ankle joint was manually full dorsal flexed 10 times for 60 seconds with a 30s interval between each 60 second period, seven days a week for four weeks, to stretch the ankle plantar flexors muscle group. At the end of the experiment, the ankles were removed, processed in paraffin, cut and stained with Hematoxilin-Eosin and Safranin-O. Two blinded observers graduated histological and histochemical findings related to cellularity, chondrocyte cloning and Safranin-O staining, observed through light microscopy. For histological and histochemical grading, the Mankin et al (1982) and LeRoux et al (2001) modified grading system was used. For statistical analysis it was used the Spearman test, Kruskal-Wallis nonparametric test with the Post Hoc Newman Keuls and Wilcoxon non-parametric test. Results: The previously immobilized stretching group (treated limbs) presented a significantly higher reduction of proteoglycans content than the solely stretched and solely immobilized groups. No significant effect of muscle stretching on treated limbs concerning cellularity and chondrocyte cloning parameters was detected. Conclusion: These findings suggest that the stretching protocol used was harmful to the previously immobilized articular cartilage. However, the same stretching protocol did not harm the cartilage of non-immobilized groups. / Objetivo: Este estudo avaliou a resposta da cartilagem articular do tornozelo de ratos, após aplicação de um protocolo de alongamento muscular passivo cíclico em animais previamente submetidos à imobilização. Materiais e Métodos: Para isso foram utilizados 22 ratos albinos adultos jovens (280+25,4g) distribuídos aleatoriamente em 4 grupos: imobilizado (I), n=6, imobilizado e alongado (IA), n=5, alongado (A), n=6 e controle (C), n=5. Nos grupos I e IA foi utilizado um modelo de imobilização que manteve a pata posterior esquerda imobilizada com o tornozelo, deste membro, em flexão plantar máxima por quatro semanas (pata tratada). Enquanto a pata posterior direita (contralateral) e as anteriores permaneceram livres para o movimento. Após a retirada do aparato de imobilização os grupos IA e A foram submetidos ao protocolo de alongamento muscular por três semanas. Seus tornozelos esquerdos foram manualmente mantidos em flexão dorsal máxima (10 repetições com 60s de duração, intercalados com 30s de relaxamento, sete dias da semana). Após as sete semanas do experimento, os tornozelos foram retirados, processados em parafina, secionados e corados com Hematoxilina-Eosina e Safranina-O. Dois observadores graduaram os achados histológicos e histoquímicos relativos a celularidade, presença de clones e ortocromasia para Safranina-O. As avaliações foram cegas. Para isso foi elaborada uma tabela de pontuação, com nível crescente de lesão, adaptada de dois sistemas de graduação para dano a cartilagem articular descritos na literatura (Mankin et al, 1971 e LeRoux et al, 2001). Os testes estatísticos não paramétricos utilizados foram: Spearman, Kruskal- Wallis com Post Hoc Newman-Keuls e Wilcoxon, considerando grau de significância de 5%. Resultados: As patas tratadas do grupo submetido ao alongamento após a imobilização apresentaram significativamente maior perda do conteúdo de proteoglicanas que as do grupo somente imobilizado. Entretanto o alongamento não gerou alterações teciduais das variáveis estudadas nas patas tratadas dos grupos que não foram previamente imobilizados. Conclusão: Esses dados sugerem que o protocolo de alongamento utilizado nesse estudo foi prejudicial somente à cartilagem articular previamente imobilizada.