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Effect of body size and posture on biomechanics of walking
Matějovská, Zuzana ; Hora, Martin (advisor) ; Farana, Roman (referee)
During human walk, we balance internal muscle forces and external forces outside of the body, while trying to minimize physiological energetic expenditure and mechanical loading on the body. The biomechanics of walking can be affected by various factors, including body size. In individuals with greater body size, the ground reaction force increases, so it is expected that joint moment of the lower limb in individuals with greater body size should increases. However, this relationship is not always true - as documented by previous studies, larger individuals use moderating mechanisms in the form of postural adjustment of the lower limb which decreases the load on joints during walking. The aim of this diploma thesis is to investigate the effect of body size and posture on the biomechanics of walking in the stance phase of walking, and to verify the presence of moderating mechanisms. We obtained kinematic and kinetic data from nineteen probands. The data was collected during three types of walking - during normal walking, walking with extended knees and crouched walking. We used Visual3D software to calculate angles in joints and joints moments of the lower limb. The independent effect of body mass, lower limb length measured in Visual3D, lower limb length measured anthropometrically, biiliac...
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The effect of various breathing variations on intra-thoracic pressure, bar kinematics and muscle activity in bench press exercise.
Blažek, Dušan ; Šťastný, Petr (advisor) ; Vágner, Michal (referee) ; Farana, Roman (referee)
Title: The effect of breathing technique on intra-thoracic pressure, kinematics of barbell, and muscle activity during bench press exercise. Objectives: The main aim of this study is to determine relationship between breathing technique and bench press exercise. Furthermore, determine which breathing modification leads to overcoming highest resistance and how each individual breathing techniques (Valsalva maneuver (VM), Hold breath (HB), Lung packing (PAC), "reversed breathing" (REVB)) affects kinematics of barbell, and muscle activity, during different intensity (1 RM, 4RM, 8RM, 12RM). Methods: Experiment of cross-sectional character, with usage of our-calibrated sensor, for intrathoracic pressure measurements, 3D kinematics with passive markers and surface electromyography. For measuring anthropometric measurements was further used goniometer, digital scale, and measuring tape. Comparisons of the breathing techniques was done by analysis of covariance ANOVA, while particular parameters were compared by Pearson correlation. Results: Except of REVB technique, which indicated significantly lower load, there was no significant difference between techniques in lifted resistance. Similar effect was observed at results of intrathoracic pressure, where REVB technique showed significantly lower pressure,...
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