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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Calcium Alleviates Symptoms in Hyperkalemic Periodic Paralysis by Reducing the Abnormal Sodium Influx

DeJong, Danica January 2012 (has links)
Hyperkalemic periodic paralysis, HyperKPP, is an inherited progressive disorder of the muscles caused by mutations in the voltage gated sodium channel (NaV1.4). The objectives of this thesis were to develop a technique for measurement symptoms in vivo using electromyography (EMG) and to determine the mechanism by which Ca2+ alleviates HyperKPP symptoms, since this is unknown. Increasing extracellular [Ca2+] ([Ca2+]e) from 1.3 to 4 mM did not result in any increases in45Ca2+ influx suggesting no increase in intracellular [Ca2+] ([Ca2+]i) acting on an intracellular signaling pathway or on an ion channel such as the Ca2+sensitive K+ channels. HyperKPP muscles have larger TTX-sensitive22Na+ influx than wild type muscles because of the defective NaV1.4 channels. When [Ca2+] was increased from 1.3 to 4 mM, the abnormal 22Na+ influx was completely abolished. Thus, one mechanism by which Ca2+alleviates HyperKPP symptoms is by reducing the abnormal Na+ influx caused by the mutation in the NaV1.4 channel.
152

The Effect of Cold Acclimation on Changes in Muscle Activity

Hans Christian, Tingelstad January 2013 (has links)
Human beings have been exposed to different cold conditions throughout time, and have through cold acclimation developed mechanisms to survive in these conditions. Cold acclimation can be elicited through exposure to natural cold climates, or artificially induced in a laboratory to study the body’s response to repeated cold exposures. Several studies looking at the effects of cold acclimation in humans have been conducted during the last 50 years, and have reported that cold acclimation can lead to a change in skin and core temperature, heat production and shivering. An accurate quantification of shivering thermogenesis (ST) during cold acclimation has not been done before, and most previous measurements of shivering during cold acclimation have been inaccurate and inadequate. In this study a Liquid Condition Suits (LCS) was used to elicit cold acclimation (10°C, 2hr daily, for 4 weeks) while an accurate measurement of the effect of cold acclimation on changes in muscle activity was conducted. In CHAPTER 2, results showed that four weeks of cold acclimation at 10°C did not change skin and core temperature, heat production or ST. The effects on shivering pattern and fuel selection were also analysed, but no effects of cold acclimation could be observed. These measurements were a part of a larger study, in which the effects of cold acclimation on changes in BAT were the main outcome measures. These data showed that an increase in BAT volume (45%) and activity (120%) were the only observed effects of cold acclimation. In CHAPTER 3, we set out to assess if changes in shivering from pre to post cold acclimation are associated with changes in BAT volume, and if the amount of BAT a participant possesses prior to cold acclimation can be used to predict changes in shivering intensity during cold acclimation. The interindividual variability in changes in thermal responses, heat production, shivering and BAT volume occurring between subjects during four weeks of cold acclimation was also addressed in this section.
153

Archery's Lasting Mark: A Biomechanical Analysis of Archery

Dorshorst, Tabitha 29 October 2019 (has links)
The physical demands of archery involve strenuous movements that place repetitive mechanical loads on the upper body. Given that bone remodels in response to mechanical loading (Ruff, 2008), it is reasonable to assume that repetitive bow and arrow use impacts upper limb bone morphology in predictable ways. The introduction and increased use of archery have been suggested to impact bilateral humeral asymmetry (Rhodes and Knüsel, 2005; Thomas, 2014). However, this claim is yet to be tested in vivo. This project aims to use kinematic and electromyographic approaches to validate claims inferring that, 1. archery places mechanical loading on the non-dominant arm resulting in lowered asymmetry, and 2. the dominant arm in archery has more mechanical loading placed in the anterior-posterior direction while the non-dominant arm has more mechanical loading placed in the medial-lateral direction. Some muscles (i.e. Pectoralis major and posterior Deltoid) act symmetrically on both humeri, while most muscle groups (i.e. Biceps brachii, Triceps brachii, Deltoid (lateral), and Latissimus dorsi) are activated asymmetrically on the humerus. On the whole, asymmetrically acting muscle groups acting on separate arms result in similar overall directional bending. Therefore, the overall cross-sectional shape of the bone would be similar for the draw and bow arm. Repeated bow use would undoubtedly induce humeral modification consistent with increased non-dominant arm robusticity, which in turn would lower asymmetry. Findings from this project thus support the hypothesis that the adoption of the bow and arrow results in decreased humeral asymmetry and strengthen morphological approaches to behavioral reconstruction.
154

Odezva biologických signálu na multimediální obsah / Response of biological signals on multimedia content

Ondrášková, Lucie January 2013 (has links)
This paper explains the concept of emotion, emotion dimension and how emotions relate to the central nervous system. Additionally, there is research that were the inspiration for this work, the basic types of emotions and their physiological responses. The following are ways to monitor signals caused by emotions. The practical part deals with the sensing signals from the periphery of the body, specifically the EDA, EMG, EOG and PPG. As stimuli to elicit these signals were used photography, music and film. The signals were processed using the program developed in Matlab. Program specific values obtained were statistically analysed.
155

Komparativní analýza vybraných typů fotbalových kopů / Comparative analysis of selected soccer kicks

Řebíček, Pavel January 2013 (has links)
Title: Comparative analysis of selected soccer kicks Objectives: The main objective of the study is to characterize the involvement of selected muscles during soccer kicks by time and space and subsequent comparison with specific exercises with expander by EMG measurement. Methods: The study has a character of a case study, comparative analysis of relative timing of movement and activity of selected muscles during soccer kicks by surface poly-electro-myographical analysis and kinematic analysis. Results: Timing of muscles involvement during soccer kicks is different than timing of muscles involvement during exercise with expander. Keywords: EMG, soccer, kick, muscles, activation
156

Optomyography: Detection of muscle surface displacement using reflective photo resistor

Raghavendra, Jammalamadaka January 2014 (has links)
A human body can carry out many physiological complex processes which can be mechanical, electrical or bio-chemical. Each mechanical activity generates a signal that describes the characteristics of the particular action in the form of pressure or temperature. Any irregularity in the process changes the usual functioning thus affecting the performance of the system. Several techniques were introduced to evaluate these muscular signals in order to get a deeper understanding of the medical abnormalities. Displacement sensors, laser optics, electrodes, accelerometers and microphones are some of the widely used devices in measuring the electrical and mechanical activities produced in the muscles. The aim of this thesis project was to find and implement a simple non-contact optical method to measure and monitor the displacements caused on the surface of the skin due to muscular movements. In this study, a device was developed using photo electric sensors that can record surface changes caused on the skin due to the movements forearm muscles. / Människokroppens aktiviteter genererar olika mätbara signaler som kan vara biokemiska, elektriska, mekaniska. Naturligtvis är det viktigt att kunna mäta dessa signaler för att kunna veta om kroppens olika organ fungerar som de ska göra eller inte. När det gäller rent mekaniska aktiviteter genereras signaler av olika typer som beskriver denna aktivitet, såsom tryck, temperatur och förflyttning. Om en sådan process avviker från det normala fallet, kommer kroppssystemets prestanda att försämras. Ett antal tekniker utvecklades för att kunna mäta dessa signaler och uppnå djupare förståelse av möjliga icke-normala medicinska konsekvenser. Förflyttningssensorer, laser optik, elektroder, accelerometrar och mikrofoner är exempel på mättekniker som används för att studera elektrisk och mekanisk aktivitet i muskelvävnader. Målet med detta arbete är att hitta, utveckla och implementera en enkel, användarvänlig, beröringsfri, optisk teknik för att mäta och studera de ytliga förflyttningar som förändrar hudytans landskap och resulterar från muskelaktiviteter och rörelser. Detta projekt resulterade i en enkel prototyp för ett mätinstrument som ser ut som ett armband med två fotoelektriska sensorer som används för att mäta hudytans förändringar på grund av olika arm- och handrörelser.
157

Evaluating Workstation Design Guidelines and their Effects on the Obese Population

Hamilton, Michael Andre 09 December 2011 (has links)
Functional limitation, postural stability, and muscle recruitment of different categories of obesity were evaluated while performing an assembly workstation task. Three workstations, those designed for the 5th, 50th, and 95th percentile workers based on anthropometric data tables, were included in the study. Functional limitation was measured using electro-goniometers and the maximum frontal functional reach (MFFR) evaluation to measure the difference in joint angles, forces plates were used to study the differences in postural stability, and EMG was used to evaluate the muscle recruitment of the soleus, frontal deltoid, and trapezius muscles. Also, a regression analysis was performed to evaluate if production efficiency rate could be predicted based on body mass index (BMI) group, gender, pace type, workstation configuration and 13 body dimensions. The results revealed that the body joint angles and muscle activation parameters were not significantly different based on the main factor BMI groups; however, significant differences were found in the two-way interactions of the BMI groups and the other factors. In regard to postural stability, the results indicated that the obese class 2 and obese class 3 groups anterior posterior sway was significantly larger than the normal weight groups. The results also revealed differences based on gender for the joint angles and muscle activation when performing the small part assemblies; however, postural sway was not affected by gender differences. Pace type (self –paced or timed-paced) significantly affected the postural stability and muscle activation when performing the work task. These differences in pace type were most prevalent when comparing the 95th percentile workstation configuration against the 5th percentile workstation configuration. In regards to productivity, gender, weight, waist-to-hip ratio and pace type seem to have a large role in the production efficiency rate. Even though an individual's BMI and the workstation layout were found to impact the body functional limitation and stability, the results showed that it doesn't affect production efficiency rate performance.
158

Muscle Strength, Motor Units, and Aging

Kaya, Ryan D. 13 June 2013 (has links)
No description available.
159

Acute Responses of Muscle Activation during Eccentric Accentuated Loaded Squats and Normal Loaded Squats in Collegiate Weightlifters

MacDonald, Christopher J 01 August 2013 (has links) (PDF)
Introduction: Resistance training overloading the eccentric phase of exercises (termed accentuated eccentric loaded; AEL) has been hypothesized to optimize adaptations to force production and muscle mass via acute postactivation potentiation (PAP). Though enhancement of performance variables via AEL or PAP is equivocal in the literature, it is understood that AEL and/or PAP will result in either positive adaptations or a lack of maladaptations. Purpose: The purpose of this work was identifying any effect of AEL squats on measures of muscle activation in collegiate weightlifters. Subjects: Eight weightlifters (age = 24.63 ± 5.58 yrs; body mass = 83.39 ± 19.40 kg; height = 169.63 ± 8.68 cm; 1.91 ± 0.63 1RM:Body Mass) completed all testing sessions. Methods: Subjects completed AEL and NOR squat sessions being nearly identical to their normal scheduled training and sEMG data from the VM, VL, and BF muscles were collected during the entirety of each session. Statistics: Nested within RMANOVAs determined any session-long effect of AEL squats and paired samples t-tests determined any PAP on activation of the VM, VL, and BF. Results: Nonsignificant differences between the AEL CON and NOR CON phases on measures of muscle activation while trends to increase activation for all muscles were evident. There was also no evidence of PAP, identified by comparing identical sets within each session. Conclusions: There was no special effect of AEL squats on thigh musculature activation and no acute PAP was elucidated on activation levels.
160

An investigation of the skeletal muscle metabolic and functional window: a multimodal non-invasive approach using 1H Magnetic Resonance Spectroscopy (1H-MRS), Magnetization Transfer (MT) and Blood Oxygen Level Dependent (BOLD) signal / A dive into the skeletal muscle metabolic and functional environment

Amador-Tejada, Alejandro Ian January 2023 (has links)
Skeletal muscle performs essential functions, including movement and posture. Musculoskeletal disorders can disrupt these functions, leading to temporary or permanent impairment. As most muscle abnormalities will cause morphological and physiological changes in skeletal muscle, identifying diseased or injured skeletal muscle relies on having a frame of reference, i.e. a correct characterization of what is considered healthy or 'normal' skeletal muscle. Non-invasive Magnetic Resonance Imaging (MRI) techniques such as 1H Magnetic Resonance Spectroscopy (1H-MRS) to assess the biochemical environment, Magnetization Transfer (MT) to study water dynamics and Blood Oxygen Level Dependent (BOLD) signal to study blood flow and relative (de)oxy-Hb concentration have yet to be extensively explored in skeletal muscle. Therefore, to improve the knowledge of the biochemical environment of skeletal muscle, a series of experiments were performed using these techniques in calf muscles. 1H-MRS investigations showed high repeatability of metabolite quantification within and across scanning sessions despite its challenges due to the high structural organization of skeletal muscle. Furthermore, differences in the metabolic profile between endurance vs. power-oriented participants at rest were found, suggesting 1H-MRS could be used as a non-invasive technique to assess muscle fiber composition. A multimodal MT, and BOLD study were performed on exercised skeletal muscle to complement the metabolic understanding of skeletal muscle. It was shown that high-quality data could be obtained in simultaneous studies of BOLD/EMG. In addition, during a multimodal MT and BOLD acquisition, MT signal showed a decrease after exercise and was linearly correlated to the BOLD signal activation. The ability of MT to distinguish between highly/lowly activated muscle groups during exercise opens the opportunity to non-invasively investigate muscle group recruitment with a higher spatial resolution compared to EMG, and lower scanning times compared to BOLD. Overall, the main purpose of this thesis was to investigate, characterize and provide unique metrics to study the functional and metabolic profile of healthy skeletal muscle at rest and during exercise. / Thesis / Master of Applied Science (MASc) / Skeletal muscle performs vital functions such as movement, heat generation, and posture. The impact of musculoskeletal disorders, which can disrupt these functions and cause temporary or permanent impairment of physical activity and movement, is expected to grow in the future. Correctly characterizing healthy or 'normal' skeletal muscle is necessary to identify diseased or injured skeletal muscle, as most muscle abnormalities cause changes in morphology and physiology. Non-invasive MRI techniques to assess the biochemical environment, water dynamics, blood flow and relative (de)oxy-Hb concentration have yet to be extensively explored in healthy skeletal muscle. Thus, the primary purpose of this thesis was to investigate, characterize and provide unique metrics to study the functional and metabolic profile of healthy skeletal muscle at rest and during exercise. The metrics investigated can be used to establish a baseline to detect abnormal skeletal muscle.

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