Made available in DSpace on 2014-06-11T19:31:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-11-27Bitstream added on 2014-06-13T20:01:43Z : No. of bitstreams: 1 guimaraes_gc_dr_jabo.pdf: 4022989 bytes, checksum: 55bb5e0b9e5da66256e886dd7c8f6782 (MD5) / Universidade Estadual Paulista (UNESP) / Com este trabalho objetivou-se descrever o comportamento do centro tendíneo, pericárdio e peritônio bovinos, submetidos a ensaios mecânicos de tração a fresco e conservados em glicerina a 98% durante 30, 60 e 90 dias, bem como, analisar suas características histológicas, utilizando técnicas de microscopia de luz e ultraestrutural. Utilizou-se para tanto dez bovinos com idade entre 30 e 36 meses, mestiços, machos e fêmeas, coletando-se de cada animal fragmentos dessas membranas. Não se observou diferenças marcantes quanto à integridade estrutural e ultraestrutural dos elementos que constituem tanto as amostras do material a fresco quanto àqueles conservados em glicerina a 98%, que exibiram células mesoteliais e fibras conjuntivas sem alterações intensas. O centro tendíneo e o peritônio não sofreram alteração significativa (p>0,05) para os valores de tensão quando comparados os testes de resistência à tração do material a fresco com os conservados em glicerina. Entretanto, todos os tecidos avaliados exibiram aumento significativo (p£0,05) para os valores de alongamento quando conservados em glicerina 98% por até 90 dias. Verificou-se que o pericárdio é a membrana que suporta as maiores tensões, ou seja, maior força de tração por área de secção. Assim, conclui-se que a glicerina é eficaz para conservação de membranas biológicas, além de alterar suas propriedades mecânicas. / With this study, it was objectified to describe the comportment of fresh and 98% glycerin conserved for periods of 30, 60 and 90 days tendinous center, pericardium and peritoneum of bovines submitted to mechanical tests of traction as well as to analyze the histological characteristics, utilizing optical microscopy and ultrastructural techniques. It was utilized ten bovines between 30 and 36 months of age, crossbreeds, males and females, collecting fragments of this membranes in each animal. There was no significant difference as for structural and ultrastrucutural integrity of the elements that constitutes the samples of fresh and 98% glycerin conserved material, evidencing mesothelial cells and connective tissue without intense alterations. The tendinous center and peritoneum didnþt suffered significant modification (p>0.05) in the values of tension when compared the resistance tests to traction in fresh with 98% glycerin conserved membranes. However, all the evalueted tissues showed significant increase (p£0.05) for the elongation values when conserved in 98% glycerin for until 90 days. It was observed that pericardium is the one which supports greaters tensions. So, it can be concluded, that glycerin is efficient to the conservation of biological membranes besides to modify its mechanical properties.

Orientador: Márcia Rita Fernandes Machado / Banca: André Luiz Quagliatto Santos / Banca: Antônio Carlos Marconi Stipp / Banca: Carlos Roberto Daleck / Banca: Maria Rita Pacheco / Resumo: Com este trabalho objetivou-se descrever o comportamento do centro tendíneo, pericárdio e peritônio bovinos, submetidos a ensaios mecânicos de tração a fresco e conservados em glicerina a 98% durante 30, 60 e 90 dias, bem como, analisar suas características histológicas, utilizando técnicas de microscopia de luz e ultraestrutural. Utilizou-se para tanto dez bovinos com idade entre 30 e 36 meses, mestiços, machos e fêmeas, coletando-se de cada animal fragmentos dessas membranas. Não se observou diferenças marcantes quanto à integridade estrutural e ultraestrutural dos elementos que constituem tanto as amostras do material a fresco quanto àqueles conservados em glicerina a 98%, que exibiram células mesoteliais e fibras conjuntivas sem alterações intensas. O centro tendíneo e o peritônio não sofreram alteração significativa (p>0,05) para os valores de tensão quando comparados os testes de resistência à tração do material a fresco com os conservados em glicerina. Entretanto, todos os tecidos avaliados exibiram aumento significativo (p£0,05) para os valores de alongamento quando conservados em glicerina 98% por até 90 dias. Verificou-se que o pericárdio é a membrana que suporta as maiores tensões, ou seja, maior força de tração por área de secção. Assim, conclui-se que a glicerina é eficaz para conservação de membranas biológicas, além de alterar suas propriedades mecânicas. / Abstract: With this study, it was objectified to describe the comportment of fresh and 98% glycerin conserved for periods of 30, 60 and 90 days tendinous center, pericardium and peritoneum of bovines submitted to mechanical tests of traction as well as to analyze the histological characteristics, utilizing optical microscopy and ultrastructural techniques. It was utilized ten bovines between 30 and 36 months of age, crossbreeds, males and females, collecting fragments of this membranes in each animal. There was no significant difference as for structural and ultrastrucutural integrity of the elements that constitutes the samples of fresh and 98% glycerin conserved material, evidencing mesothelial cells and connective tissue without intense alterations. The tendinous center and peritoneum didnþt suffered significant modification (p>0.05) in the values of tension when compared the resistance tests to traction in fresh with 98% glycerin conserved membranes. However, all the evalueted tissues showed significant increase (p£0.05) for the elongation values when conserved in 98% glycerin for until 90 days. It was observed that pericardium is the one which supports greaters tensions. So, it can be concluded, that glycerin is efficient to the conservation of biological membranes besides to modify its mechanical properties. / Doutor

O tendão de Aquiles e os músculos flexores plantares têm um papel fundamental em atividades de vida diária como o levantar de uma cadeira, durante a marcha e o salto. Mudanças na sobrecarga mecânica podem levar tanto a adaptações benéficas nas propriedades mecânicas e morfológicas da unidade músculo-tendão do tríceps sural, como após o exercício físico sistematizado, quanto à perda da estrutura e da funcionalidade, como ocorre na ruptura total do tendão de Aquiles e no envelhecimento. A avaliação das propriedades estruturais e mecânicas do tríceps sural é fundamental para que se possa identificar a perda da condição de saúde, assim como também as melhoras decorrentes do processo de recuperação das estruturas musculoesqueléticas durante um programa de reabilitação. Para tanto, é fundamental que a metodologia empregada para a avaliação das propriedades estruturais e mecânicas da unidade músculo-tendínea do tríceps sural seja confiável, e que os resultados não sejam influenciados pelo avaliador (boa reprodutibilidade inter-avaliador) ou pelo dia e horário de avaliação (boa reprodutibilidade intra-avaliador). Entretanto, ainda faltam evidências na literatura referentes à obtenção de variáveis psicométricas relacionadas à avaliação das propriedades mecânicas e morfológicas do tendão de Aquiles e da arquitetura muscular dos flexores plantares em sujeitos saudáveis. Nessa perspectiva, a presente dissertação apresenta três estudos, a fim de atingir os seguintes objetivos: (Estudo 1) verificar a reprodutibilidade intra e inter-avaliador da arquitetura muscular dos flexores plantares em indivíduos saudáveis. (Estudo 2) Verificar a reprodutibilidade intra e inter-avaliador da morfologia tendínea do tendão de Aquiles em indivíduos saudáveis (Estudo 3) Verificar a reprodutibilidade intra e inter-avaliador das medidas da capacidade de produção de força do tríceps sural. Os três estudos foram realizados no Setor de Plasticidade Neuromuscular do LAPEX da ESEFID-UFRGS. Todos os participantes foram avaliados nos parâmetros de arquitetura muscular dos flexores plantares (comprimento de fascículo, ângulo de penação e espessura muscular) e do tendão de Aquiles (área de seção transversa e comprimento do tendão total livre) por meio de ultrassonografia musculo esquelética. Contrações voluntárias máximas isométricas foram realizadas em um dinamômetro isocinético. As avaliações ocorreram em 2 momentos distintos: dia 1 e dia 2 pelo avaliador 1 (7 dias de intervalo entre as coletas), e posteriormente dia 2 pelos avaliadores 1, 2 e 3 de forma sucessiva. A análise dos dados foi realizada no software SPSS v. 20.0, por meio de estatística descritiva (média, DP - desvio padrão) e inferencial (CCI – Coeficiente de Correlação Intraclasse; EPM – Erro Padrão entre Medidas = DP√(1-CCI); MMD – Mínima Mudança Detectável = 1,96*EPM), e intervalo de confiança. No estudo 1 verificamos uma alta correlação intra e inter-avaliador para espessura muscular, ângulo de penação e comprimento do fascículo dos flexores plantares (CCI>75), e valores baixos de EPM e MMD. No estudo 2, verificamos uma alta correlação intra e inter avaliador para comprimento do tendão total e área de secção transversa (CCI>75) Entretanto, para a variável de tendão livre, a correlação inter avaliador foi pobre (CCI: 0,580). Comparando a experiência dos avaliadores, os avaliadores 1 e 2 obtiveram um CCI de 0,910, enquanto que entre os avaliadores 1 e 3 o CCI foi de 0,340, e entre os avaliadores 2 e 3 o CCI foi de 0,280. Essas correlações muito baixas para a variável do tendão livre podem ser explicadas pela diferente experiência dos avaliadores e pelo tempo de treinamento na obtenção das medidas. No estudo 3, verificamos uma alta correlação intra e inter-avaliador para os valores de torque isométrico em rampa dos músculos flexores plantares (CCI>90), e valores baixos de EPM e MMD. Conclui-se, a partir dos estudos acima, que existe uma alta confiabilidade das medidas de arquitetura muscular e tendínea e de força tanto intra-avaliador quanto inter-avaliador. Além disso, os dados poderão servir como banco de dados de uma condição de saúde para comparação com dados de pacientes que sofreram lesões no tendão de Aquiles. A metodologia também pode ser aplicada na avaliação de pacientes. Entretanto, alguns aprimoramentos nas técnicas utilizadas são necessários a fim de melhorar a reprodutibilidade e reduzir ainda mais os erros de medida. / The Achilles tendon and the plantar flexor muscles play a key role in daily life activities such as raising from a chair, during gait and jump. Changes in mechanical overload can lead to both beneficial adaptations in the mechanical and morphological properties of the triceps surae muscle-tendon unit, such as after systemic exercise, as well as after the loss of structure and functionality after total Achilles tendon rupture and aging. The evaluation of the triceps surae structural and mechanical properties is fundamental so that losses in the health condition can be identified, as well as the improvements resulting from the recovery process of the musculoskeletal structures during a rehabilitation program. Therefore, it is fundamental that the methodology used to evaluate the structural and mechanical properties of the triceps surae muscle-tendon unit is reliable, and that the results are not influenced by the evaluator (high inter-rater reliability) or by the day and time of evaluation (high intra-rater reliability). However, there is still a lack of evidence in the literature regarding the psychometric variables related to the evaluation of the mechanical and morphological properties of the Achilles tendon and the plantar flexors muscular architecture in healthy subjects. In this perspective, the present dissertation presents three studies in order to achieve the following objectives: (Study 1) To verify the intra- and inter-rater reliability of the plantar flexors muscle architecture in healthy individuals. (Study 2) To verify intra- and inter-rater rater Achilles tendon morphology evaluation in healthy individuals. (Study 3) To verify intra and inter-rater reliability of the triceps surae isometric strength measurements The three studies were performed at the Neuromuscular Plasticity Sector of LAPEX of ESEFID-UFRGS. All participants were evaluated in their triceps surae muscle architecture (fascicle length, pennation angle and muscle thickness) and the Achilles tendon (cross-sectional area, tendon length and free tendon length) parameters by means of skeletal muscle ultrasonography. Maximal isometric voluntary contractions were performed on an isokinetic dynamometer. The evaluations occurred in 2 different moments: day 1 and day 2 by evaluator 1 (7-days interval between collections), and on the second day by 2 additional evaluators (2 and 3) in a successive way. Data analysis was performed in SPSS v. 20.0, by means of descriptive statistics (mean, SD - standard deviation) and inferential analysis (ICC - Intraclass Correlation Coefficient - SEM - Standard Error between Measures = DP√ (1 - ICC) MDC – Minimum Detectable Change = 1.96*EPM), and confidence interval analysis. In study 1, we verified a high intra- and inter-rater correlation for muscle thickness, pennation angle and fascicle length (ICC> 75), and low SEM and MDC values. In study 2, we found a high intra- and inter-rater correlation for total tendon length and cross-sectional area (ICC> 75). However, for the free tendon variable, the inter-rater correlation was low (ICC: 0.580). Comparing the evaluators' experience, evaluator 1 and 2 obtained a ICC of 0.910, whereas evaluators 1 and 3 had an ICC of 0.340, while between evaluators 2 and 3 the ICC was 0.280 These very low correlations for the free tendon variable can be explained by the evaluators' experience and by the training of the measurements. In study 3, we verified a high intra- and inter-rater correlation for isometric torque values of the plantar flexor muscles (ICC> 75), and low SEM and MDC values. Based on the above evidences, we can conclude that there is a high intra-rater and inter-rater reliability for muscle architecture, tendon structure and plantar flexor strength. In addition, our data can be used as a data base for the healthy condition for the comparison with patients with Achilles tendon injury. Our methodology can also be used in patients’ evaluation. However, some improvements in the used techniques are necessary to improve reliability and further reduce measurement errors.

L’objectif général de ce travail doctoral était de étudier la résultante entre les bénéfices induits par l’activité physique chronique et les effets délétères de l’avancée en âge sur la fonction d’équilibration. Pour cela, différentes techniques de manipulations sensorielles (e.g. stimulation vestibulaire galvanique, vibration tendineuse, électromyostimulation, tapis de mousse) ont été employées dans le cadre de tâches posturales bipodales. Les principaux résultats montrent que les manipulations sensorielles affectent le contrôle postural quel que soit l’âge et le niveau de pratique physique du sujet. Par ailleurs, l’avancée en âge semble majorer les effets perturbateurs des manipulations sensorielles. Le comportement postural observé pourrait, en grande partie, résulter d’une dégradation de la proprioception. Lorsque l’information proprioceptive est manipulée (i.e. vibration tendineuse), le groupe de sujets âgés ne pratiquant aucune activité physique saturerait plus rapidement le système proprioceptif que les autre groupes de sujets. En revanche, l’activité physique chronique limiterait la dégradation de la capacité d’équilibration. Elle pourrait améliorer la capacité des sujets âgés à recalibrer l’information sensorielle erronée et renforcerait l’efficacité de la proprioception. En filigrane, une optimisation fonctionnelle du système postural permettrait de compenser partiellement les effets du vieillissement. En effet, les involutions qui s’opèrent au cours de l’avancée en âge au niveau des systèmes sensoriels et du système nerveux central s’avèrent inéluctables. Elles empêchent les sujets âgés pratiquant une activité physique régulière de maintenir une habileté à compenser une perturbation posturale similaire à celle de sujets jeunes sportifs. / The overall objective of this thesis was to analyse the benefits resulting from the chronic physical activity and the deleterious effects induced by aging on postural control. To this end, different sensory manipulation techniques (e.g. vestibular galvanic stimulation, tendon vibration, electromyostimulation, foam surface) were used in the context of bipedal postural tasks. The main results showed that sensory manipulations affect postural control whatever the age and the level of physical practice of the subject. In addition, the disruptive effects of the sensory manipulations on postural control seem to increase with aging. This postural behaviour could largely result from the involution of the proprioception. When proprioception is disrupted (i.e. tendon vibration), the non-active old subjects group would saturate the proprioceptive system more quickly than the other groups. In contrast, the chronic physical activity would limit the involution of the postural control effectiveness. It could improve the ability of the old subjects to reweight sensory information and enhance the proprioception effectiveness. Hence, a functional postural control optimization might partly compensate the aging effects. Indeed, age-related involutions of sensory systems and central nervous system occurring across life span are inevitable. They prevent the older subjects who practice regular physical activity to maintain a similar ability to cope with postural disruptions in comparison with young athletes.

Sehnen übertragen die Muskelkräfte und ihre Eigenschaften beeinflussen unsere Bewegungsleistungen. Infolge mechanischer Belastungen adaptieren Sehnen. Die Effekte spezifischer Parameter des mechanischen Dehnungsstimulus sowie allgemeiner Belastungsbedingungen auf die Anpassung sind bisher ungeklärt und sollen durch die vorliegende Arbeit beleuchtet werden. Das adaptive Potential wurde durch einen Vergleich der Sehneneigenschaften zwischen beiden Beinen, in Bezug auf seitenabhängige Belastungen, experimentell untersucht. Um den Effekt verschiedener interventionsinduzierter Belastungen auf die Anpassung zu bestimmen, wurde ein systematischer Review nebst Metaanalyse durchgeführt. Der Einfluss spezifischer Parameter des Dehnungsstimulus (Rate und Dauer) wurde mittels zweier Trainingsinterventionen untersucht. Der Vergleich zwischen den Achillessehneneigenschaften des dominanten und nicht dominanten Beins zeigte einen signifikanten Unterschied des Young''s Modulus (Materialeigenschaften), mutmaßlich eine Folge seitenabhängiger Alltagsbelastungen. Die Metaanalyse ermittelte hohe Effektgrößen auf die mechanischen und Materialeigenschaften sowie eine niedrige Effektgröße auf die Morphologie, mit einem signifikanten Einfluss der unterschiedlichen Belastungen. Die beiden Interventionen belegten, dass eine hohe Rate der Dehnung und eine lange Dauer keinen übergeordneten Stimulus zur Sehnenanpassung im Vergleich zu einer hohen Magnitude und niedrigen Frequenz darstellen. Die Ergebnisse zeigen, dass Materialeigenschaften sensitiver gegenüber Belastungsänderungen sind und im Vergleich zur Morphologie zeitiger adaptieren. Die Interventionsresultate lassen den Schluss zu, dass eine hohe Dehnungsmagnitude, eine adäquate Dauer und repetitive Belastung essentiell für einen effektiven Stimulus sind. Die Ergebnisse liefern wichtige Erkenntnisse bezüglich einer Verbesserung von Sehneneigenschaften im Kontext der athletischen Leistung sowie Verletzungsprävention und -rehabilitation. / Tendons transmit the force exerted by a muscle and their properties influence human locomotor performance. Furthermore, tendons adapt to mechanical loading. The effect of specific parameters of the mechanical strain stimulus as well as general loading conditions on tendon adaptation is not completely understood and, therefore, the focus of research in the present thesis. Adaptive responses were investigated by means of a comparison of tendon properties between both legs to assess the effect of side-dependent loading pattern. A systematic review and meta-analysis was applied to examine the influence of various intervention-induced loading conditions on the magnitude of adaption. To investigate specific parameters of the mechanical strain stimulus (rate and duration), two controlled exercise interventions were conducted. The comparison of the Achilles tendon properties between the non-dominant and dominant leg revealed a significant difference of the Young''s modulus (i.e. material properties), likely a result of side-dependent daily loading pattern. The meta-analysis revealed high intervention effect sizes on the tendon mechanical and material properties and a low effect size on the morphology, with a notable effect of the various loading conditions. The two exercise interventions showed that a higher rate of strain and longer duration did not provide a superimposed effect for tendon adaptation compared to high magnitude and low frequency. The findings indicate that the material properties seem to be more sensitive and quicker in response to changes in the loading conditions compared to the morphological properties. The results of the two interventions suggest that a high strain magnitude, an appropriate strain duration and repetitive loading are essential for an effective stimulus. These findings provide valuable information with regard to the improvement of tendon properties in the context of athletic performance as well as injury prevention and rehabilitation.