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Viscous and elastic properties of soft tissue "in situ"
Moravcová, Kamila ; Šifta, Petr (advisor) ; Bittner, Václav (referee)
Title: Viscousand elastic properties of soft tissue"in situ" Goals and methods: The aim of this thesis is to measure the viscoelastic properties of human soleus muscle and Achilles tendonin vivo and post mortem in situ. It is a pilot study that uses myotonometry as the method of measurement. Based on the response of connective tissues on deformation made by tip of myotonometer, resp. its viscoelastic properties, curves in graphsare created. Three main described parameters of thecurveare steepness, deflection and its surface area. Main goal of the experiment is to compare properties of different types of tissue and their potential differences while denervated or innervated. Results of this study may help with better understanding of the soft tissues behavior in response to manual therapeutic contact. The study also describes the differences between in vivo and post mortem tissue properties that may be help further studies which use post mortem tissues to predict in vivo behavior. Results: Soft tissues in vivo have higher viscosity. In comparison, post mortem tissues have significantly higher stiffness and energy dissipation than in vivo. Elasticproperties of denervated soft tissue manifest with approx. 7 secondsdelay. Viscoelastic properties of muscle tissueshow changes depending on deeper...
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The effect of intensity of voluntary isometric contraction on rheological characteristics of skeletal muscle tissue in vivo, in situ
Kopecká, Barbora ; Bittner, Václav (advisor) ; Jelen, Karel (referee)
Title: The effect of intensity of voluntary isometric contraction on rheological characteristics of skeletal muscle tissue in vivo, in situ Objectives: The main aim of this study is to determine the effect of intensity of isometric voluntary contraction of skeletal muscle on its viscoelastic characteristics. The work also aims to contribute to the verification of myotonometer as an objective diagnostic instrument and compares it to known methods for evaluation of muscle tone, or its partial characteristics. Methods: We used myotonometer - utility model 29456 for evaluation of changes of stiffness and viscous behavior of skeletal muscle in vivo, in situ in 20 healthy volunteers. The values were compared during 0%, 20%, 35% and 50% of maximal strength of isometric contraction of finger flexors, controlled by hand-held dynamometer. Results: We concluded that both stiffness and viscous behavior of skeletal muscle increases with higher intensity of isometric voluntary contraction. Keywords: myotonometer, skeletal muscle, viscous behavior, stiffness, muscle tone
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Possibilities of the use of indentation tests while studying the mechanical properties of soft tissues of the human locomotor system in vivo, in situ
Bittner, Václav ; Šifta, Petr (advisor) ; Bunc, Václav (referee) ; Čapek, Lukáš (referee)
POSSIBILITIES OF THE USE OF INDENTATION TESTS WHILE STUDYING THE MECHANICAL PROPERTIES OF SOFT TISSUES OF THE HUMAN LOCOMOTOR SYSTEM IN VIVO, IN SITU ABSTRACT: The aim of this work was to analyze possibilities of the use of indentation tests, while studying mechanical properties of human locomotor system soft tissues in vivo, in situ. The synthesis of published findings and the results of our own surveys were used. A mathematical model of the indentation test was created as a part of theory. The geometry of the task was formulated as a solid cylinder penetrating into an infinite half-space made of viscoelastic material. The solution is based on the traditional analytical approach concerning stationary loading of flexible material. This procedure is generalized for Neo-Hooke's hyperelastic material and large deformations. The quantification of dissipative processes is based on the assumption that the stress tensor of a viscoelastic material can be decomposed into a purely elastic constituent and a purely dissipative constituent. The model enables to determine both elastic and viscous properties of the material. Experimental part of the work includes validation experiments. Based on the findings, it can be stated that myotonometry is a valid diagnostic method that allows an objective assessment of muscle tone...
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The effect of intensity of voluntary isometric contraction on rheological characteristics of skeletal muscle tissue in vivo, in situ
Kopecká, Barbora ; Bittner, Václav (advisor) ; Jelen, Karel (referee)
Title: The effect of intensity of voluntary isometric contraction on rheological characteristics of skeletal muscle tissue in vivo, in situ Objectives: The main aim of this study is to determine the effect of intensity of isometric voluntary contraction of skeletal muscle on its viscoelastic characteristics. The work also aims to contribute to the verification of myotonometer as an objective diagnostic instrument and compares it to known methods for evaluation of muscle tone, or its partial characteristics. Methods: We used myotonometer - utility model 29456 for evaluation of changes of stiffness and viscous behavior of skeletal muscle in vivo, in situ in 20 healthy volunteers. The values were compared during 0%, 20%, 35% and 50% of maximal strength of isometric contraction of finger flexors, controlled by hand-held dynamometer. Results: We concluded that both stiffness and viscous behavior of skeletal muscle increases with higher intensity of isometric voluntary contraction. Keywords: myotonometer, skeletal muscle, viscous behavior, stiffness, muscle tone
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Viscous and elastic properties of soft tissue "in situ"
Moravcová, Kamila ; Šifta, Petr (advisor) ; Bittner, Václav (referee)
Title: Viscousand elastic properties of soft tissue"in situ" Goals and methods: The aim of this thesis is to measure the viscoelastic properties of human soleus muscle and Achilles tendonin vivo and post mortem in situ. It is a pilot study that uses myotonometry as the method of measurement. Based on the response of connective tissues on deformation made by tip of myotonometer, resp. its viscoelastic properties, curves in graphsare created. Three main described parameters of thecurveare steepness, deflection and its surface area. Main goal of the experiment is to compare properties of different types of tissue and their potential differences while denervated or innervated. Results of this study may help with better understanding of the soft tissues behavior in response to manual therapeutic contact. The study also describes the differences between in vivo and post mortem tissue properties that may be help further studies which use post mortem tissues to predict in vivo behavior. Results: Soft tissues in vivo have higher viscosity. In comparison, post mortem tissues have significantly higher stiffness and energy dissipation than in vivo. Elasticproperties of denervated soft tissue manifest with approx. 7 secondsdelay. Viscoelastic properties of muscle tissueshow changes depending on deeper...
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