Lower Back Disorders account for 16-19% of work related claims and 33-41% of dollars paid in workers? compensation (as cited in Marras, 1999), with impacts to society approaching $100 billion dollars annually (as cited in Marras et al., 1999). Dr. William Marras engineered a device to track trunk kinematics in order to develop a Job Risk Classification Model for predicting high-risk group probability of lower back injury. The device has been validated, but other technologies such as 3-D motion capture can potentially gather the same data. This study examined the use of motion capture to apply two- and three-plane lifting tasks to the Marras model and compare results with commonly used assessment techniques. Regardless of the fact that the Marras model results were drastically different from NIOSH and RULA, motion capture was able to gather all necessary data for running the models and has a promising future in ergonomic assessments.

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One of the purposes of this study is to develop a vision system consisting of 3 inexpensive, commercial cameras. The system is intended to be used for tracking the motion of objects in a large calibration volume, typically 6.5 m. wide and 0.7 m. high. Hence, a mechanism is designed and constructed for the calibration of the cameras. The second purpose of the study is to develop an algorithm, which can be used to obtain the kinematic data associated with a rigid body, using a vision system. Special filters are implemented in the algorithm to identify the 3 markers attached on the body. Optimal curves are fitted to the position data of the markers after smoothing the data appropriately. The outputs of the algorithm are the position, velocity and acceleration of any point (visible or invisible) on the body and the angular velocity and acceleration of the body. The singularities associated with the algorithm are also determined. Using the vision setup and the developed algorithm for tracking the kinematics of a rigid body, the motions of the saddles of different horses are investigated for different gaits. Similarities and differences between horses and/or gaits are analyzed to lead to quantitative results. Using the limits induced by the whole body vibration of humans, for the first time in the world, daily, allowable riding time and riding distances are determined for different horses and gaits. Furthermore, novel, quantitative horse comfort indicators are proposed. Via the experiments performed, these indicators are shown to be consistent with the comfort assessment of experienced riders. Finally, in order to implement the algorithms proposed in this study, a computer code is developed using MATLAB&reg / .

Thesis (MScPhysio)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The aim of this study was to improve the measurement of postural dynamism in the sitting position using a three-dimensional (3D) motion analysis system. The primary objective was to describe pilot data for postural dynamism of the cervical and thoracic spines while working at a desktop computer. The secondary objective was to refine the process of posture measurement and analysis by decreasing data processing time. Certain factors in 3D motion analysis can lead to an increase in gaps in data collected during trial capture, which in turn will lead to a longer time of data processing. In the first phase of this study, a number of such factors were identified and altered. A series of pilot studies was performed to test the improvement of data processing time when altering these factors. In the first two pilot studies, camera and tripod positionings were explored and refined, workstation layout and anatomical landmark marker placement were investigated, and optimal capture frequency was established. In both these pilot studies, outcomes were established by means of trial and error by experimenting with a variety of different options for the different outcomes. In the third pilot study, computer software which provides computer tasks for the participant during primary trial capture was tested. Two independent computer users performed all the activities as per software, after which they were required to give oral feedback and suggestions on improvement in terms of user friendliness. The objective of the fourth and final pilot study was to include all of the outcomes from the preceeding pilot studies and attempt a trial run of the actual data collection process. A study participant with no affiliation to the research project was used and a complete trial run was performed after which the measurement process was deemed feasible. In the primary study, 18 student volunteers completed a sequence of computer tasks, including keyboard, mouse and reading activities. Prior to data capture, full range of motion of the thoracic and cervical spines were measured in three dimensions for every participant. Data capture took place for the full duration of performance of all computer activities. Outcome parameters for postural dynamism included true range of motion (degrees), proportional range of motion (percentage) and motion frequency (movement per minute) in all three planes of motion of the cervical and thoracic spines. Typing tasks were associated with biggest movement ranges and motion frequencies. Mouse activity was associated with the most stationary posture, exhibiting the least frequent movement as well as the smallest ranges of motion. The results from this study allow us to better understand the dynamic nature of posture, as well as postural dynamism associated with different computer tasks. This study provides a baseline for future research of 3D motion analysis of the sitting posture. It also marks the need for further research regarding ergonomics, use and potential alternatives in the computer workstation and input devices. / AFRIKAANSE OPSOMMING: Hierdie studie het ten doel gehad om die meting van posturale dinamisme in die sitposisie te verbeter deur middel van „n drie-dimensionele (3D) bewegingsanalisesisteem. Die primêre doelwit was om loodsdata te beskryf vir posturale dinamisme van die servikale en torakale werwelkolomme terwyl op „n rekenaar gewerk word. Die sekondêre doelwit was om die proses van postuurmeting en analise te verfyn deur die dataprosesseringstyd te verminder. Sekere faktore van 3D bewegingsanalise kan „n vermeerdering van gapings in ingesamelde data tot gevolg hê, wat weer kan lei na „n verlengde tydperiode van dataprosessering. In die eerste fase van hierdie studie is sulke faktore identifiseer en aangepas. „n Reeks loodsstudies is uitgevoer om die verbetering van dataprosesseringstyd te toets namate aanpassings aan hierdie faktore gemaak is. Tydens die eerste twee loodsstudies is verskillende kamera en driepoot posisionering ondersoek en verfyn, werkstasie uitleg en anatomiese baken merker plasing is ondersoek en die optimale dataversamelingsfrekwensie is vasgestel. In beide hierdie loodsstudies is die uitkomste vasgestel op grond van toets- en fouteer deur te eksperimenteer met „n verskeidenheid opsies soos van toepassing op die betrokke uitkomste. Tydens die derde loodsstudie is rekenaarsagteware getoets wat die rekenaaraktiwiteit vir die studiedeelnemers verskaf het tydens primêre data-insameling. Twee onafhanklike persone het al die aktiwiteite volgens die sagteware voltooi en het verbale terugvoer en aanbevelings gegee oor hoe om die program te verbeter. Die vierdie en finale loodsstudie het gepoog om al die uitkomste van die eerste drie loodsstudies in te sluit en „n toetsmeting te doen van die ware dataversamelingsproses. „n Onafhanklike studiedeelnemer met geen affiliasie tot die navorsingsprojek nie het „n toetslopie van die hele versamelingsproses gedoen en die metingsproses is haalbaar verklaar. Tydens die primêre studie het 18 student-vrywilligers „n reeks rekenaartake gedoen (insluitend sleutelbord en muisaktiwiteite sowel as „n leesopdrag). Voor die aanvang van dataversameling is die volle bewegingsomvange van die torakale en servikale werwelkolomme van elke deelnemer gemeet. Dataversameling is vir die volle durasie van die uitvoer van rekenaaraktiwiteite gedoen. Uitkomsparameters vir posturale dinamisme het die volgende ingesluit: Omvang van beweging (grade), proporsionele omvang van beweging (persentasie) en bewegingsfrekwensie (bewegings per minuut) in al drie bewegingsvlakke van die servikale en torakale werwelkolomme. Sleutelbord-aktiwiteite is geässosieer met die grootste bewegingsomvange en die meeste bewegingsfrekwensie. Muisaktiwiteit is geässosieer met die mees stasionêre postuur en het die heel minste gereelde beweging getoon in die algemeen. Die resultate van hierdie studie help om die dinamise natuur van postuur beter te verstaan, sowel as posturale dinamisme wat met verskillende rekenaartake verbind word. Die studie bied „n basislyn vir die toekomstige navorsings wat posturale dinamisme met verskillende rekenaartake meet. Dit merk ook die behoefte aan verdere navorsing aangaande ergonomika, gebruik en alternatiewe tot rekenaarwerkstasie en –toerusting.

L’analyse du mouvement, ou l’analyse d’une séquence d’images, est l’extension naturelle de l’analyse d’images à l’analyse de séries temporelles d’images. De nombreuses méthodes d’analyse de mouvement ont été développées dans le contexte de la vision par ordinateur, incluant le suivi de caractéristiques, le flot optique, l’analyse de points-clef, le recalage d’image, etc. Dans ce manuscrit, nous proposons une boite a outils de techniques d’analyse de mouvement adaptées à l’analyse de séquences biomédicales. Nous avons en particulier travaillé sur les cellules ciliées qui sont couvertes de cils qui battent. Elles sont présentes chez l’homme dans les zones nécessitant des mouvements de fluide. Dans les poumons et les voies respiratoires supérieures, les cils sont responsables de l’épuration muco-ciliaire, qui permet d’évacuer des poumons la poussière et autres impuretés inhalées. Les altérations de l’épuration mucociliaire peuvent être liées à des maladies touchant les cils, pouvant être génétiques ou acquises et peuvent être handicapantes. Ces maladies peuvent être caractérisées par l’analyse du mouvement des cils sous un microscope avec une résolution temporelle importante. Nous avons développé plusieurs outils et techniques pour réaliser ces analyses de manière automatiques et avec une haute précision, à la fois sur des biopsies et in-vivo. Nous avons aussi illustré nos techniques dans le contexte d’éco-toxicité en analysant le rythme cardiaque d’embryons de poissons / Motion analysis, or the analysis of image sequences, is a natural extension of image analysis to time series of images. Many methods for motion analysis have been developed in the context of computer vision, including feature tracking, optical flow, keypoint analysis, image registration, and so on. In this work, we propose a toolbox of motion analysis techniques suitable for biomedical image sequence analysis. We particularly study ciliated cells. These cells are covered with beating cilia. They are present in humans in areas where fluid motion is necessary. In the lungs and the upper respiratory tract, Cilia perform the clearance task, which means cleaning the lungs of dust and other airborne contaminants. Ciliated cells are subject to genetic or acquired diseases that can compromise clearance, and in turn cause problems in their hosts. These diseases can be characterized by studying the motion of cilia under a microscope and at high temporal resolution. We propose a number of novel tools and techniques to perform such analyses automatically and with high precision, both ex-vivo on biopsies, and in-vivo. We also illustrate our techniques in the context of eco-toxicity by analysing the beating pattern of the heart of fish embryo

De etiologia multifatorial, a síndrome dolorosa fêmoro-patelar (SDPF) acomete de 7 a 15% da população, em sua maioria jovens, adultos e ativos. Causa dor difusa anterior ou retropatelar e é exacerbada durante atividades funcionais, como subir e descer degraus, permanecer por um período prolongado sentado, agachado ou ajoelhado (COWAN, BENNELL e HODGES, 2002). Tanto o processo de avaliação quanto a evolução do tratamento baseiam-se, fundamentalmente, no relato de dor feito pelo paciente e na incapacidade funcional. Diagnosticar corretamente o distúrbio possibilitaria um tratamento mais adequado e permitiria o acompanhamento do quadro evolutivo do paciente ao longo do tratamento proposto. Desta maneira, propôs-se a análise de alguns parâmetros biomecânicos para melhor caracterização destes indivíduos. 33 voluntárias - 11 com diagnóstico médico de dor fêmoro-patelar e 22 clinicamente normais - foram submetidas à avaliação por meio de eletromiografia de superfície das porções medial e lateral do quadríceps; análise tridimensional de movimento; e plataforma de força durante a subida de degraus. As voluntárias do grupo SDFP foram caracterizadas por um atraso no tempo de atividade máxima do músculo vasto medial em relação ao vasto lateral (4 ms), aumento da rotação externa do fêmur (3,14 graus) e menor variação global do torque (1,14 Nm), quando comparadas aos indivíduos do grupo controle. Os resultados obtidos complementam-se e ajudam a entender características de comportamento neuromotor em indivíduos com dor fêmoro-patelar. Conjuntamente, esses instrumentos apresentam grande potencial para a avaliação e classificação dos indivíduos com relação à síndrome. / From multifactorial etiology, patellofemoral pain syndrome (PFPS) affects 7 to 15% of the population, mostly young, adults and active people. It causes anterior or behind patella diffuse pain and is exacerbated during functional activities such as climbing and descending stairs or stay for a long time sitting, kneeling or crouching down (COWAN, BENNELL e HODGES, 2002). The evaluation process as much as the evolution of treatment is fundamentally based in the reporting of pain by the patient and the functional disability. Correct diagnostic of the disorder would allow a more appropriate treatment as well as to keep up with the patient evolution during the proposed treatment. Thus, it was proposed the biomechanical analysis of some parameters to better characterize these individuals. 33 female volunteers - 11 with medical diagnosis of patellofemoral pain and 22 clinically normal - were submitted to evaluation of surface electromyography of the medial and lateral portions of the quadriceps, three-dimensional motion analysis and force plate during the ascent of steps. The volunteers of the PFPS group were characterized by a delay in time of maximum activity of the vastus medialis muscle related to the vastus lateralis (4 ms), increased femoral external rotation (3.14 degrees) and less overall variation in the torque (1.14 Nm) when compared to individuals in the control group. The results complement each other and help to understand features of neuromotor behavior in individuals with patellofemoral pain. Together, these tools have great potential for assessment and classification of these individuals related to the syndrome.

Considerando que a duração do combate de judô pode variar entre poucos segundos até um período superior a 5 min, a caracterização da demanda fisiológica do combate na sua duração regulamentar e fracionada, assim como a relação dessas respostas com o nível de aptidão aeróbia e anaeróbia dos atletas é relevante para o aperfeiçoamento dos métodos de treinamento. Assim, o objetivo do presente estudo foi analisar a aptidão física, ações técnicas e respostas fisiológicas durante a luta de judô com diferentes durações. Para tanto, 12 atletas de judô foram submetidos a 10 sessões de avaliação. Nas duas primeiras sessões foram realizados quatro testes físicos para caracterização da aptidão aeróbia e anaeróbia dos membros superiores e inferiores. Nas demais sessões, os atletas foram submetidos a 15 combates simulados de judô (3 condições x 5 durações - 1, 2, 3, 4 e 5 min) com o mesmo oponente, em ordem aleatória e vendados quanto à duração do combate. Em uma das condições, os atletas simularam um combate real. Na segunda condição, os atletas lutaram usando um analisador de gases para mensurar o consumo de oxigênio, para a estimativa da contribuição dos sistemas de transferência de energia. Nessa condição foram impostas algumas adaptações de movimento. Para verificar se o uso do analisador de gases modificou as respostas obtidas, na terceira condição, os atletas lutaram com as mesmas adaptações, porém não usaram o equipamento. Em cada sessão foram conduzidos dois combates, intercalados por 60 min de recuperação. Foram quantificadas as respostas fisiológicas, perceptivas, de desempenho, de estrutura temporal e ações técnicas em todos combates. A comparação das variáveis dependentes foi realizada com uma análise de modelos mistos para medidas repetidas, seguida do post hoc de Bonferroni. As associações entre a aptidão aeróbia e anaeróbia com as variáveis do combate foram verificadas por meio da correlação de Pearson. Para todas as comparações pareadas significantes foi calculado o tamanho do efeito (d de Cohen). Em todas as análises foi adotado 5% como nível de significância. Os principais resultados demonstraram aumento da contribuição aeróbia com concomitante redução da contribuição dos sistemas anaeróbios com o transcorrer do combate, sendo a contribuição aeróbia superior à contribuição dos sistemas anaeróbios a partir do primeiro min de combate. O sistema anaeróbio lático contribuiu com a menor proporção do custo energético do combate de judô. As taxas de incremento das respostas fisiológicas e perceptivas por min de combate foram reduzidas com o transcorrer do combate, sendo as principais modificações observadas no início do combate, sugerindo que os atletas podem apresentar estratégia para modular seus esforços. Com o transcorrer do combate observou-se manutenção do tempo médio de esforço e ações aplicadas, porém houve aumento do tempo médio dos períodos de pausa. Após a realização do combate observou-se declínio da resistência muscular dinâmica dos membros superiores, manutenção da força isométrica máxima de preensão manual e melhora da potência muscular dos membros inferiores. As variáveis de aptidão aeróbia e anaeróbia relacionaram-se com menor queda do desempenho, maior taxa de golpes de perna e maior tempo médio de combate. Assim, observou-se predominância do sistema aeróbio para suprir a energia necessária para a realização do combate de judô. Além disso, maiores níveis de aptidão aeróbia e anaeróbia estão associados positivamente com o desempenho durante a luta / Considering that judo combat can last from a few seconds to up to more than 5 minutes, characterization of the physiological demands of combat in different time frames, and the relationship of these responses to an athlete\'s level of aerobic and anaerobic fitness is relevant to improving training methods. Thus, the objective of the present study was to describe the physiological demands of judo combat. Twelve judo athletes performed 10 experimental sessions. In the first and second sessions, four physical tests to characterize the aerobic and anaerobic fitness of the upper and lower limbs were performed. In the other sessions, the athletes performed 15 judo combat (involving 3 conditions x 5 durations of time: 1, 2, 3, 4 and 5 minutes) randomly determined, against the same opponent, on different days and blinded for time duration. In one condition, the athletes simulated actual combat. In the second condition, the athletes fought while using a gas analyzer to measure oxygen consumption in order to estimate the contribution of the energy systems. In this condition some motion adjustments were imposed. To verify if the use of the gas analyzer modified the responses obtained, in the third condition the athletes fought with the same adjustments, but did not use the equipment. These combat periods were divided into 8 sessions with two different conditions, separated by an interval of 60 minutes. The physiological, perceptual, performance, time-motion, and technical action responses were quantified in all matches. The comparison of the dependent variables was performed with an analysis of mixed models for repeated measures, followed by a post hoc Bonferroni. The associations between aerobic and anaerobic fitness to combat variables were verified using Pearson\'s correlation. For all significant pairwise comparisons the effect size (d Cohen) was calculated. A 5% level of significance was adopted for all analyses. The main results showed an increase in aerobic contribution with a concomitant reduction of the anaerobic contribution in the course of combat, given that the aerobic contribution was greater than the anaerobic contribution from the first minute of combat. The lactic anaerobic system contributed to the smaller proportion of energy cost in judo combat. The increment in rate of the physiological and perceptual responses per minute of combat decreased throughout the course of the combat, with the highest changes occurring at the beginning of combat, which suggest that judo athletes seem to modulate their effort. In the course of combat, maintenance of the average time of effort and actions occurred, but there was an increase in the average time of pause. After the combat, a decline in the dynamic strength endurance of the upper limbs was observed, while maximal isometric handgrip strength was maintained, and improvement of muscle power in the lower limbs was noted. The aerobic and anaerobic fitness variables were associated with lower fall performance, higher rate of leg attacks and a higher average time of standing combat. Thus, a predominance of the aerobic system in supplying the energy needed for the realization of judo combat was observed. In addition, higher levels of aerobic and anaerobic fitness are positively associated with performance during the combat