Thesis (Ph. D.)--Michigan State University, 2005. / Includes bibliographical references (leaves 326-336).

Thesis (Ed. D.)--University of Virginia, 2005. / Includes bibliographical references (leaves 91-97).

Thesis (M.Sc.)--York University, 2005. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 70-88). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11787

Thesis (M.A.)--York University, 2005. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 32-36). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11750

Thesis (Ed. D.)--University of Virginia, 2005. / Includes bibliographical references (leaves 91-97). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--Springfield College, 2006. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Perception of effort, defined as “the conscious sensation of hard, heavy and strenuous exercise”, is known to regulate endurance performance and human behaviour. Perception of effort has recently been shown to be exacerbated by mental exertion and is also known to be a main feature of fatigue. However, to date, not only its neurophysiology but also how manipulations of perceived exertion might impact endurance performance remain poorly understood. The main aim of this thesis was to investigate how manipulations of perceived exertion might impact endurance performance. This thesis is divided in two parts: central and peripheral manipulations of perceived exertion. In each part, three experimental chapters aimed to get a better insight in the neurophysiology of perceived exertion and its impact on endurance performance. In the first part (central manipulations), we firstly investigated the impact of exacerbating perceived exertion via mental exertion involving the response inhibition process on self-paced running endurance performance. This study demonstrated that as with time to exhaustion tests, time trial performance is impaired following mental exertion leading to mental fatigue. Secondly, we investigated whether mental exertion leading to mental fatigue could alter the rate of central fatigue development during constant load whole-body exercise. This study demonstrated that the exacerbated perception of effort in presence of mental fatigue does not reflect an altered rate of central fatigue development, but is likely to be due to i) an impaired central motor command and/or ii) an alteration of the central processing of the corollary discharge. Thirdly, we investigated whether mental exertion could impact the repeatability of maximal voluntary contraction of the knee extensors. We found that contrary to submaximal exercise, force production capacity is not altered by mental exertion. Finally, these three studies demonstrated that i) mental exertion negatively impacts submaximal exercise but not maximal exercise and that ii) mental fatigue differs from central fatigue. In the second part (peripheral manipulation), we firstly developed and tested the reliability of a new endurance exercise model non-limited by the cardiorespiratory system (one leg dynamic exercise), which will be of benefits for future researches aiming to manipulate feedback from group III-IV muscle afferents. Secondly, we described neuromuscular alterations induced by this exercise and tested a new methodology to indirectly measure feedback from group III-IV muscle afferents. This study demonstrated that one leg dynamic exercise induced central and peripheral fatigue and also a decrease in spinal excitability associated with an increase in cortical excitability. Furthermore, this study also suggests that monitoring cardiovascular responses during muscle occlusion might be a suitable tool to indirectly measure feedback from group III-IV muscle afferents. Thirdly, we tested the corollary discharge and afferent feedback model of perceived exertion with electromyostimulation. This study demonstrated for the first time that for the same force output, perception of effort generation is independent of muscle afferents and reflects the magnitude of the central motor command (manipulated by electromyostimulation). All together, these findings provide further evidence in support of the corollary discharge model of perceived exertion, and provide a new exercise model to investigate and manipulate perception of effort. This thesis, when integrating both experimental parts, provides new insight on how perception of effort regulates endurance performance. Specifically, it demonstrates how muscle fatigue is a contributor of the continuous increase in perception of effort during endurance exercise, but also that other contributors play a role in this increase in perception of effort. Indeed, we demonstrated for the first time that i) perception of effort alterations in the presence of mental fatigue is independent of any alterations of the neuromuscular system, and ii) muscle afferents does not directly impact perception of effort, but may influence it indirectly via their role in motor control.

INTRODUCTION: Osteochondritis dissecans (OCD) of the capitellum is a focal condition affecting the articular cartilage and subchondral bone, typically in adolescent athletes. Limited data exists regarding the indications and expected outcomes of the various treatment methods of capitellar OCD, and the optimal treatment strategy remains controversial. Risks of progressive capitellar OCD include osteoarthritic changes and permanent elbow disability. STUDY AIMS: The objective of this literature review is to assess the data and the conclusions to be drawn from the existing literature on the differential indications for the various treatment options for capitellar OCD, using low-level meta-analysis and qualitative observations, to suggest a course of future study with the purpose of clarifying the differential treatment indications and improving the care of capitellar OCD patients. The most recent 10 years (2004-2014) of data are the focus, in order to evaluate the most modern indications, surgical techniques, surgical skills, and clinical outcomes. DISCUSSION OF PUBLISHED DATA: Ultrasound reportedly offers a high predictive value for screening baseball players for capitellar OCD, although sensitivity, specificity, and cost-effectiveness are unknown. Plain radiographs and magnetic resonance imaging (MRI) are useful diagnostic resources for making the decision to operate, but their sensitivities and specificities are imperfect. Evidence suggest that early stage OCD in physically immature patients may recover with non-operative management, while advanced stage OCD in older patients will likely achieve a better recovery with operative management. Risk factors for poor outcomes following surgical management of capitellar OCD may reportedly include patient age, physical maturity, athletic competition level, large lesion diameter and thickness, and lateral lesion location. The advantages of removal, debridement, and marrow stimulation techniques include the minimal invasiveness associated with arthroscopy. Successful fragment fixation can preserve normal articular properties, but may risk implant complications and secondary surgeries. Mosaicplasty is frequently suggested when patient or lesion characteristics seem to preclude other surgical methods, or when prior surgical treatment attempts fail, but disadvantages of mosaicplasty include the technical complexity of the procedure and the risk of donor site morbidity. CONCLUSIONS: The capitellar OCD literature has accumulated a wealth of level IV case series reporting generally satisfactory short-term results of the various surgical options. There is little need for more descriptive literature on this topic at this time. Modern treatment strategies are incomplete and poorly defined, based upon the suggestions of small case series offering disorganized, low-quality data. A study of the cost-effectiveness of ultrasound screening in high-risk athletes would be useful. A large, comparative case-control study or prospective cohort study of higher methodological quality and better standardization is needed to advance the knowledge on this topic, and classification and regression tree analysis could be applied meaningfully. With more organized data and analysis, it will become easier to take a systematic approach to treating capitellar OCD, settle clinical controversy and improve patient outcomes.

Thesis (M.A.)--Boston University / Sports-related concussions are a very large public health concern and have only recently been brought into the national spotlight, thanks largely to the increased media coverage following the deaths of several current and former players of the National Football League (NFL). This problem extends not only to professional athletes, but reaches down through college, high school and to our youth athletes as well. The symptoms resulting from concussion are diverse and include both acute and long-term effects, and could have particularly debilitating effects on the developing brains of young athletes. Various neurocognitive deficits, as well as neurodegenerative diseases such as chronic traumatic encephalopathy (CTE) have been associated with concussions. Research about both the short and long-term effects of concussions has been growing in recent years, and will continue to grow as advanced neuroimaging tools and biomarkers become better developed. This will improve diagnostic capabilities, result in better prognoses, as well as treatments and prevention. This review analyzes current literature in order to evaluate the lasting impacts of sports-related concussions. By showing the effects of sports-related concussions, especially on the developing brain, policy changes aimed at the prevention of concussion in sports will be suggested, specifically in terms of mitigating the adverse effects of concussions on brain development.

Orientador: José Alexandre Curiacos de Almeida Leme / Banca: Julio Wilson dos Santos / Banca: Andressa Coope dos Santos / Resumo: O diabetes mellitus é um quadro patológico que traz diversas complicações como prejuízos metabólicos, endócrinos, cognitivos, sarcopenia, emagrecimento, hiperfagia e polidispia. Estudos prévios têm demonstrado que a manutenção de animais em ambiente enriquecido traz um conjunto de benefícios através dos estímulos que oferece, sendo a atividade física um desses estímulos. Apesar disso, poucos estudos investigaram os efeitos da manutenção de animais diabéticos em ambiente enriquecido. Desta forma, a presente dissertação teve por objetivos investigar os efeitos do diabetes na atividade física realizada no ambiente enriquecido e investigar os efeitos do ambiente enriquecido em parâmetros bioquímicos, morfométricos, cognitivos e nas proteínas AKT, RhoA e RhoE musculares. Para isso, na primeira etapa do desenho experimental, ratos wistar foram distribuídos em dois grupos: controle e diabetes. O diabetes foi induzido por estreptozotocina via intraperitonial (50 mg/kg) e os animais foram inseridos em gaiolas amplas contendo objetos coloridos e rodas de atividade com contador de giros. O rastreamento foi realizado pelo sistema para análises cinemáticas, Digital Video For Biomechanics - Windows 32 bits (DVIDEOW® ) e software Matlab® . Na segunda etapa do desenho experimental, os animais foram distribuídos nos seguintes grupos: controle, diabetes e diabetes gaiola enriquecida. O diabetes foi induzido por estreptozotocina via intraperitonial (50 mg/kg) e os animais foram mantidos em gaiolas padrão ou ambiente enriquecido. A massa corporal, ingestão hídrica e alimentar foram coletadas duas vezes por semana e a glicemia no início e final do experimento. Ao final do período experimental foi registrado o comprimento corporal e coletadas amostras do músculo gastrocnêmio para as análises da fosforilação da AKT e expressão de RhoA e ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Diabetes mellitus is a pathological condition that brings several complications such as metabolic, endocrine, cognitive loss, sarcopenia, weight loss, hyperphagia and polydipsia. Previous studies have shown that keeping animals in enriched environment brings a set of benefits through the stimuli it provides, and the physical activity is one of these stimuli. Despite this, few studies have investigated the effects of the maintenance of animals in diabetic enriched environment. The present dissertation aimed to investigate the effects of diabetes on physical activity performed in the enriched environment and to investigate the effects of enriched environment on biochemical parameters, morphometric, cognitive, and AKT, RhoA and RhoE proteins in the muscle. For this, in the first step of the experimental design, wistar rats were distributed into two groups: control and diabetes. Diabetes was induced streptozotocin via intraperitoneal (50 mg/kg) and the animals were placed in large cages, containing colored objects and the wheels of activity and a counter of revolutions. The tracking was carried out by the system for analysis, kinematics, Digital Video For Biomechanics - 32-bit Windows (DVIDEOW®) and Matlab® software. In the second step of the experimental design, the animals were distributed into the following groups: control, diabetic and diabetic - enriched cage. Diabetes was induced streptozotocin via intraperitoneal (50 mg/kg) and the animals were kept in cages of standard or enriched environment. The body mass, the intake of water and food were collected twice per week and the blood glucose at the beginning and end of the experiment. At the end of the experimental period was recorded and the length of the body and collected samples of the gastrocnemius muscle for the analysis of the phosphorylation of AKT and expression of RhoA and RhoE. For these analyses, ... (Complete abstract click electronic access below) / Mestre