Master's thesis topic: Influence of rheological characteristics of muscle tissue by musculus triceps surae by means of AEK practice Author: Bc. Karel Kupec Branch of study: Physiotherapy Disertation Tutor: PhDr. Petr Šifta, Ph.D. Year of Defense: 2013 Abstract: The target of this thesis was find out the effect of agistic-excentric contractions on muscle tension of musculus soleus compared with passive relaxation of musculus soleus. The assumption was, that agistic-excentric contraction reduce muscle tension of musculus soleus after anaerobic load. The contralateral lower limb was control limb for comparison agistic-excentric contraction and passive relaxation. Muscle tension was measured in laboratory in Faculty of Physical Education and Sport, Charles University: five students were measured. As a measurement method was used myotonometry, which simulated palpation. Measured data were displayed by using an analog-digital convertor and consequently evaluated. The results of this study found out positive effect of agistic-excentric contraction on muscle tension. Control form of relaxation, passive relaxation, didn't influence muscle tension so significantly. The results support the principle of hypotheses, that agisctic-exentric contraction approach affect muscle tension more positive than passive...

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.

La marche humaine nécessite la génération de force propulsive ainsi que des forces antigravitaires pour maintenir l’équilibre. Pour cela, le système nerveux central est requis d’orchestrer la contraction des muscles des membres inférieurs, notamment les fléchisseurs plantaire de la cheville qui interface entre le sol et le corps humain. Durant la première phase de simple appui, le triceps sural (TS) est en contraction excentrique et son activation aide à soutenir le corps en résistant à la rotation du tibia sur le Tarsus. Par contre, la phase finale de simple appui est marquée par une augmentation des forces de réactions au sol « Push-off », du couple articulaire de la cheville et de l’activité électromyographique du TS. Le rôle du TS durant la phase finale de simple appui est l’objet de débat dans la littérature, où certains lui attribut le rôle de propulseurs et d’autre de soutien du corps. Dans ce travail, nous postulons que l’augmentation de l’activité du TS en phase finale de simple d’appui sert uniquement à décélérer la chute du centre de masse. En outre, nous postulons que la modulation temporelle de l’activité du TS permet de contrôler la cinématique (cadence et longueur de pas) et la cinétique de la marche. Deux études ont été mises en places pour tester les hypothèses de travail. Des données biomécaniques mesurées à partir d’une plateforme de force et l’activité EMG du soléaire et des gastrocnémiens latéral et médial de la jambe d’appui ont été collecté pour les deux études. Dans la première études des volontaires ont initié la marche sans et avec un ajout de poids de 20 kg attaché au niveau de la ceinture abdominale. L’ajout du poids augmente les forces de propulsion. Une augmentation de l’activité EMG du triceps permettrait de comprendre si le triceps participe à la génération de force propulsive. La deuxième étude est composée de deux expérimentations. Dans la première expérimentations des volontaires ont accompli 3 conditions de initiation de marche à vitesse variée tout en maintenant la longueur de pas constante. Dans la deuxième expérimentation, les sujets ont été incliné et instruit de récupérer leur équilibre en exécutant un pas de longueur différente. Les résultats ont montré que : 1) le triceps ne participe pas au push-off mais freine la chute du centre de masse en phase finale de simple appui. 2) L'amplification d’activité électromyographique durant la marche rapide est due à l’augmentation de demande de support de corps causé par la croissance des forces inertiels du corps. 3) La durée de contraction du TS permet de déterminer la cadence et la longueur de pas, donc la cinématique de la marche. La durée d’activité du TS permet aussi de déterminer la position du centre de masse par rapport au centre de pression au moment du contact avec le sol. 4) Ceci permet au TS de moduler le couple de déséquilibre responsable des forces propulsives, donc la cinétique de la marche. / Human gait necessitates the generation of both propulsive force to propel the body forward and anti-gravitational force to maintain dynamic postural equilibrium. This requires the central nervous system to orchestrate lower limb muscles. Notably the CNS has to control ankle plantar flexors activity as the whole body rotates around the ankle, which in turn interfaces with the external environment. From early to middle stance, triceps surae (TS) contracts eccentrically thus resisting tibial rotation around the tarsus. However, late stance is marked by an increase in ground reaction forces, commonly known as « Push-off », in ankle torque and electromyographic activity of TS. The role of triceps surae during late stance is object of debate in the literature. Some believe it is responsible for the push-off other insist it is sole role is to maintain dynamic postural equilibrium. In this work, we postulate that the increase in TS activity in late stance is to decelerate vertically the fall of the centre of mass. We further hypothesise that temporal modulation of TS activity determines global gait kinematics (cadence and step length) and kinetics. Two studies have been conducted to test the work hypotheses. Ground reaction force data gathered from a large force platform and EMG activity of soleus, medial and lateral gastrocnemius of stance was measured using surface electrodes. In the first study, subjects initiated gait with and without an added mass of 20 kg attached around the waist. Adding the weight increases propulsive force. If TS activity increases as well than it is responsible for generating propulsive force. The second study is composed of two experiments. In the first volunteers performed gait initiation at three different walking velocity conditions while maintain step length constant. In the second experiment, subjects were inclined and asked to recuperate their equilibrium by performing a step. They were asked to perform three step lengths. Results showed that: 1) Triceps does not participate in push-off but brakes the fall of the centre of mass during late single stance. 2) Increasing TS EMG activity in late stance is due to an increase in the requirement of maintaining dynamic postural equilibrium. 3) Control over the duration of TS activity determines cadence and step length and thus the kinematics of gait. Temporal modulation of TS also sets the position of centre of mass with respect to centre of pressure at the moment of foot-contact. 4) By controlling the distance between the two, the CNS modulates the disequilibrium torque that is responsible for propulsive force and thus the kinetics of gait.

Made available in DSpace on 2016-06-02T19:22:55Z (GMT). No. of bitstreams: 1 4273.pdf: 640166 bytes, checksum: 0c9fc1f3e1c6ddb8472d73914461506a (MD5) Previous issue date: 2012-03-30 / Universidade Federal de Sao Carlos / Although tissue cooling is widely used in the treatment of musculoskeletal disorders there is still controversy about its effects on muscular performance. It is important to study this issue since cooling is also combined with exercise. Objective. To compare the effects of ice pack and cold water immersion on the muscular performance parameters of plantar flexors and electromyography (EMG) activity of the triceps surae. Design. Subjects were randomly assigned treatment with either ice pack (n=20) or cold water immersion (n=21). Independent variables were cold modality (ice pack or cold water immersion), muscle action (isometric and concentric isokinetic, angular velocity of isokinetic test (60 and 120°/s) and measurement time (pre- and post-cooling). Dependent variables were skin temperature, muscular performance and EMG activity. Methods. The sample included 41 healthy men with a mean age of 22.15 (SD=2.89). In each group one of the two cold modalities was applied to the calf region for 20 minutes. Skin temperature, plantar flexors muscular performance parameters and EMG activity of the triceps surae were measured before and after cooling. Results. Ice pack increased isometric peak torque. Both cold modalities reduced EMG activity in both muscles during isometric contraction. Both cold modalities reduced peak torque and total work during isokinetic contraction at both velocities. Ice pack was more effective at reducing EMG activity in isokinetic contractions. Limitations. The examiner was not blinded regarding treatment group and the population included only young healthy participants. Conclusions. Ice pack and cold water immersion showed similar effects on muscular performance, which depends on the muscle action performed. Cooling decreased isokinetic performance and the ice pack increased isometric torque. The results suggest that caution is required when performing activities after cooling, especially tasks involving maximal isokinetic contractions. / Embora o resfriamento tecidual seja amplamente utilizado no tratamento de lesões músculo esqueléticas há ainda controvérsias sobre seus efeitos no desempenho muscular. Estudar esse aspecto é importante uma vez que o resfriamento também é utilizado associado a exercícios físicos. Objetivo: Comparar os efeitos do pacote de gelo e da imersão em água gelada sobre parâmetros do desempenho muscular dos flexores plantares e atividade eletromiográfica (EMG) do tríceps sural. Desenho: Foi realizado um estudo experimental com distribuição aleatória dos participantes em dois grupos de intervenção, pacote de gelo (n=20) e imersão em água gelada (n=21). As variáveis independentes foram grupo experimental (pacote de gelo ou imersão em água gelada), tipo de contração (isométrica ou isocinética concêntrica), velocidade angular do teste isocinético (60 e 120°/s) e tempo de mensuração (pré- e pós-resfriamento). Variáveis dependentes foram temperatura da pele, parâmetros de desempenho muscular e atividade EMG. Métodos: Quarenta e um homens saudáveis, com média de idade (DP) de 22,15 (2,89) anos participaram do estudo. Cada grupo recebeu uma das duas modalidades de resfriamento, aplicada sobre a região da panturrilha por 20 minutos. A temperatura da pele e parâmetros do desempenho muscular dos flexores plantares e da atividade EMG dos músculos sóleo e gastrocnêmio medial e lateral foram avaliados antes e imediatamente após o resfriamento. Resultados: O pacote de gelo causou aumento no pico de torque isométrico. A atividade EMG foi reduzida em ambos os músculos sóleo e gastrocnêmio pelas duas modalidades de resfriamento durante a contração isométrica. As duas modalidades de resfriamento reduziram o pico de torque e trabalho total na contração isocinética em ambas as velocidades avaliadas. De modo geral, o pacote de gelo foi mais efetivo para reduzir a atividade EMG na contração isocinética. Conclusões: O pacote de gelo e a imersão em água gelada mostram efeitos similares sobre o desempenho muscular, o qual é dependente a ação muscular realizada. O resfriamento muscular diminui o desempenho durante a contração isocinético e o pacote de gelo aumenta o torque isométrico. Os resultados sugerem cautela quando forem realizadas atividades dinâmicas após o resfriamento, especialmente durante contrações isocinéticas máximas.

Title: Consequences of forced hypokinesia on human movement aparatus. Objectives: The aim of this study was to find out the influence of forced hypokinesia after total hip replacement on the excitability of α motoneurons. I deal with the changes of H-reflex and M-wave latencies and the changes of the recruitment curves. The results of the operated and non-operated (kontrol) lower limb were compared. Methods: Five volunteers 3 - 4 weeks after total hip replacement participated in this study. The age was 62,4 (± 3,01). The H-reflex was elicited by stimulation of tibial nerve in a poplitel fossa. The H-reflex and M-wave latencies and its recruitment curves were obtained. After that the values of the operated lower limb were compared with the non-operated one (control). The results were evaluated as case studies. The EMG device Grass Telefactor was used to detect the electrical potential of soleus muscle. The rectangular pulses of 0,5 ms duration were used for stimulation tibial nerve by Grass 88 Stimulator. Then the data were transduced by CED Power 1401 device. Results: We found out that the H-reflexes of both lower limbs were not elicited in the case study no. 2 and the H-reflex of a control lower limb was not elicited in case study no. 1. The stimulus intensities for eliciting H-reflex and M-wave...