Orientadores: Jacques M. E. Vielliard, Fausto Berzin / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-25T21:20:06Z (GMT). No. of bitstreams: 1 Ricarte_RobertoNatalino_D.pdf: 9390651 bytes, checksum: 2a773adc940945989a857796158a2693 (MD5) Previous issue date: 1999 / Resumo: Este estudo teve como objetivo investigar, utilizando-se da artrosonografia, os fenômenos sonoros articulares do joelho, através de processamento digital. Participaram da pesquisa, duzentos e quinze (215) voluntários de ambos os sexos, com idades entre 10 a 75 anos, sendo que destes, cento e quarenta e cinco (145) relataram a ausência de qualquer tipo de disfunção articular e setenta (70) eram portadores de doenças reumáticas. As gravações dos sons articulares do joelho foram obtidas através da utilização de um microfone de condensador ultradirecional "Sennheiser" e de um gravador analógico Kudeslki S.A, em uma sala acústica do Departamento de Otorrinolaringologia do Hospital das Clínicas da Universidade Estadual de Campinas - UNICAMP. Posteriormente as gravações foram tratadas e analisadas no laboratório de Bio-acústica do Departamento de Zoologia do Instituto de Biologia da UNICAMP. Neste estudo, em princípio, tanto os indivíduos sem história de disfunção particular, classificados como portadores de joelhos "assintomáticos", quanto os indivíduos portadores de doença reumática, classificados como portadores de joelhos "sintomáticos", foram analisados como fazendo parte de uma amostra comum, devido ao fato de que no momento, este estudo se preocupou apenas em identificar, reconhecer e analisar os fenômenos sonoros articulares observados. Do total da amostra, observou-se joelhos com um padrão articular silencioso, nos quais ocorreu uma ausência completa de qualquer fenômeno sonoro audível e joelhos com padrão articular fraco, médio e forte, estes classificados de acordo com a maior ou menor quantidade de fenômenos sonoros presentes nas gravações. Com relação ao tempo, foram observados fenômenos sonoros de curta duração: o estalido, o estalo e o baque articular e de longa duração, a crepitação articular. Os fenômenos sonoros articulares observados no joelho em movimento, foram analisados em função de três parâmetros: a sua forma de onda, o seu espectro de freqüência e a sua densidade espectral de potência, esta, somente para aqueles de curta duração. Ficou demonstrado através dos resultados obtidos neste estudo, que a utilização da técnica artrosonográfica para a gravação dos sons articulares é eficiente, permitindo caracterizar adequadamente os fenômenos sonoros articulares do joelho. 'Para o propósito desta pesquisa, o microfone de fato, se mostrou um instrumento eficiente e adequado, durante as gravações na aquisição do som articular do joelho, isto porque ele registra todas as suas características intrínsecas, permitindo identificar cada fenômeno sonoro de sua composição com clareza / Abstract: The purpose of this study is to investigate the knees articular sonorous phenomena, through arthrosonography, using digital processes. Two hundred and fifteen (215) volunteers, of both sexes, with ages varying between 10 and 75, participated in this study. From this total, 145 volunteers didn't have a historic of articular diseases and 70 had rheumatic diseases. The recording of the knees articular sounds was obtained in an a,coustic chamber, using a Sennheiser ultradirectional condenser microphone and a Kudelski . analogic tape recorder. The recordings were subsequently transferred to a Taskam digital tape recorder and then to a microcomputer, in order to be handled and analyzed. The results obtained indicated that both the knees of the volunteers without articular diseases (assymptomatic knee) and the ones of those with rheumatic diseases (symptomatic knees) could be included in a common classification. This is due to the fact that the purpose of this study was only to identify, recognize and analyze the articular sonorous phenomena observed. Concerning the time scale, during the knee movement, articular sonorous phenomena of short duration, such as claps, cracks and thuds, could be observed. In these cases, the duration of the sound remained between 0.02 and 0.04 seconds. Sonorous long time knee phenomena, with duration of about 1.0 second, such as articular crepitation, were present. Knees were classified as "sonorous silence type", when the total absence of articular sonorous phenomena was registered by the microphone in the recordings. Knees were classified as "weak, medium and strong sonorous type" depending on the minar or major presence of articular noises in the recordings. Three parameters were used in the analysis of those articular sounds: waveforms, frequency noise spectrum and potential spectra density. The potential spectra density was used only to analyze short time phenomena. The results of this study showed that the arthrosonography technique is, a good toei for recording and analyzing articular sounds produced during the knees movements, allowing a good characterization of articular sonorous phenomena. For the purpose of this study, the microphone proved to be a good transducer in terms of frequency and dynamic sensitivities, for utilization in human joint emissions, since it captures ali the characteristics of the articular sounds, allowing the identification of each acoustic phenomenon through its spectral composition / Doutorado / Doutor em Biologia e Patologia Buco-Dental

M.Tech. (Chiropractic) / Please refer to full text to view abstract

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Knee-ankle-foot orthoses (KAFOs) are full leg braces for individuals with knee extensor weakness, designed to support the person during weight bearing activities by preventing knee flexion. KAFOs typically result in an unnatural gait pattern and are primarily used for level ground walking. A novel variable resistance orthotic knee joint was designed and evaluated to address these limitations. This low profile design fits beneath normal clothing. Mechanical and biomechanical testing demonstrated that the design resisted knee motion during stance phase, released the knee joint without restricting the knee’s range of movement, and provided flexion resistance during stair descent. Design modifications and related testing procedures were developed to further improve joint performance and to validate the design prior to testing on individuals with knee extensor weakness.

The sit-to-stand (STS) is a multi-articular movement of daily living that requires significantly higher knee extensor (KE) efforts compared to ankle and hip musculature, which approach near maximal levels in older adults populations. As well, fatigue may develop more readily with repetitive actions. Consequently, it is understandable how KE strength reserves have been previously correlated with both functional independence and STS strategy characteristics in older persons, and why STS capacity is a significant predictor of disability. However, it is still unclear why compensatory movement strategies manifest when rising from a seated position, and how this may be influenced by aging. The purpose of this thesis compilation was to evaluate alterations in muscular contributions at the ankle, knee, and hip, in relation to STS performance strategies in young and older adults either: a) with repetitive multi-joint STS exercise or b) before and after isolated fatigue of KE musculature. Results showed that aging caused a redistribution of joint torques when ascending from a seated position, and was associated with significantly higher quadriceps muscular efforts in older persons in comparison to their younger counterparts. In contrast, young and older adults exhibited similar compensatory movement and loading strategies during repetitive STS exercise, which appeared to be limited by the ability to sustain KE force output. In turn, lower KE strength reserves of older persons were responsible for their disproportionately higher quadriceps efforts and reduced STS capacities. Young and older persons also appeared to employ motor strategies to compensate for reduced KE force output via increased contribution of the biarticular rectus femoris within the quadriceps KE synergy, as well as through increases in the initially less active ankle plantar flexor and hip extensor musculature. Older adults may benefit from strengthening of thigh extensor musculature to maintain or improve their strength reserves to promote independent living.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23379号 / 医博第4748号 / 新制||医||1052(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 石見 拓, 教授 戸口田 淳也, 教授 中山 健夫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

ACL (anterior cruciate ligament) injuries of the knee joint alter biomechanics and may cause abnormal loading conditions that place patients at a higher risk of developing osteoarthritis (OA). There are multiple types of ACL reconstruction (ACLR), but all types aim to restore anterior tibial translation and internal tibial rotation following surgery. Analyzing knee joint contact loads provide insight into the loading conditions following ACLR that may contribute to the long-term development of OA. Ten ACLR subjects, who underwent the same reconstruction, performed gait and cycling experiments while kinematic and kinetic data were collected. Inverse dynamic analyses were performed on processed data using OpenSim to calculate reconstructed and contralateral knee joint contact loads which were then compared between gait and cycling at both moderate and high resistances. Significant differences were found between gait and cycling at either resistance for tibiofemoral (TF) compressive, anterior shear, lateral shear forces, and internal abduction and internal rotation moments for both ACLR and contralateral knees. Anterior shear force was largest for cycling at a high resistance, however, since the ACL provides a posterior restoring force and is more engaged at low flexion angles, adjusting for flexion angles when measuring AP shear forces should be considered. Overall, the calculated loading conditions suggest cycling provided better joint stability by limiting anterior tibial translation and internal tibial rotation compared to gait. The results suggest cycling is a better rehabilitation exercise to promote graft healing and limit abnormal loading conditions that increase the risk of developing OA.

Loss of mobility and independence directly affects the quality of life of many vulnerable individuals. To address this, researchers have developed wearable walking assist exoskeletons to aid users with their daily activities. While this technology has advanced tremendously in the past decade, current exoskeletons cause discomfort and injuries to the user, leading to device rejection. This research intends to develop a kinematically compatible knee joint suitable for exoskeletons. The proposed knee design can be adapted to accommodate an offset and optimize force delivery. This is achieved by ensuring that the mechanical and biological joint rotation axes are aligned and that the moment arm varies throughout flexion. Model simulations and mechanical testing of fabricated prototypes were achieved to analyze and validate the design. The results confirm the kinematic compatibility of the design and that the moment arm could be varied throughout flexion to achieve optimal and effective moment transfer.