Made available in DSpace on 2014-06-11T19:28:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-02Bitstream added on 2014-06-13T20:58:31Z : No. of bitstreams: 1 nagata_ey_me_guara.pdf: 791649 bytes, checksum: 1efe0eefda24d10c59961eebcddf116e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O judô é um esporte muito praticado no mundo. Para o seu desenvolvimento necessita - se de uma quantidade maior de pesquisas na área de biomecânica. Devido ao esporte ser acíclico há muita dificuldade de conseguir equipamentos que façam análise da maneira mais próxima de uma situação real de luta. Este trabalho faz um estudo de uma metodologia de treinamento, utilizando plataforma de força, eletromiógrafo e técnicas de cinemetria, envolvendo a técnica de judô Morote Seoi Nage. O treinamento de entrada e projeção de golpes foi dividido em três situações diferentes. A primeira com o uke (atleta que recebe o golpe) estático, a segunda com o uke saltando e sendo projetado no momento ascendente da impulsão e a terceira com o uke saltando e sendo projetado no momento descendente da impulsão. Foram analisadas as atividades elétricas dos músculos Reto Femoral e Gastrocnêmio Médio do tori (atleta que executa o golpe) e a força de reação do solo do tori. Foram verificadas as diferenças do treinamento nas três situações. Na fase ascendente a força foi 36% menor comparada à fase descendente. Os resultados indicam que o método de treinamento proposto (fase ascendente) exigiu menor esforço para aplicação do golpe, utilizando um dos princípios definidos por Jigoro Kano, da máxima eficiência com menor esforço / Judo is a worldwide practiced sport. A larger amount of research in the biomechanics field is needed for its development. Given the fact that this is a non-cyclic sport, there is a lot of trouble in finding equipments that are able to perform evaluations closer enough to a real combat situation. This work studies a training method, using a force platform, electromyography, and image processing, involving the Morote Seoi Nage judo technique. The training of entry and projection of strikes was divided in three different situations. The first with a static uke (the athlete that is being stroken), the second with a jumping uke being projected at the upwards impulsion instant and the third with a jumping uke being projected at the downwards impulsion instant. The electrical activities of the tori’s rectus femoris and the gastrocnemius muscles (tori is the athlete that performs the strike) were analyzed as well as its ground reaction force. The training differences between the three situations were analyzed. The results show that the proposed training method (upward phase) required less effort when the strike is performed, requiring 36% less effort compared to the downwards phase, using one of the rudiments defined by Jigoro Kano, of the maximal efficiency with the minimum effort

Orientador: Araildo Lima da Silva / Banca: José Elias Tomazini / Banca: Arnaldo Luiz Leon Blum / Resumo: Fixadores externos constituem um importante recurso dentro do arsenal terapêutico dos ortopedistas na reparação das fraturas. Estão disponíveis em diversos modelos e sistemas, sempre fixados ao osso do paciente e com suas estruturas de sustentação permanecendo externamente à pele. Dentro de suas inúmeras aplicações nos dias atuais, destacam-se no tratamento inicial das fraturas expostas, uma vez que conferem estabilidade ao osso fraturado deixando um mínimo de material de síntese interno, o que minimiza as infecções. Dessa forma, sua disposição espacial necessita se planejada e confeccionada rapidamente, uma vez que suas peças são disponibilizadas separadas, ficando o resultado final em sua grande parte na dependência da experiência do cirurgião ortopedista. Este projeto visa gerar conhecimentos a respeito da análise computadorizada da biomecânica do sistema osso-fixador, direcionando o uso dos fixadores externos a uma aplicação menos empírica e com maior previsibilidade de seu comportamento em função das cargas a que será submetido. / Abstract: External fixation equipment is now an important part of the therapeutic arsenal of orthopedicians when setting and repairing fractures. They are available in various models and several systems, always fixed to the patient's skin. Among the innumerable ways that this equipment is used nowadays, the initial treatment of exposed fractures stands out since it provides stability to the fractured bone at the same time that it leaves a minimum of internal synthesis matter or material, thus minimizing infection. In this way, the equipment's spatial placement needs to be planned and it should be rapidly put together, since the different parts are available separately leaving the final result largely dependent on the orthopedic surgeon's experience. This project has as its goal the creation of knowledge in relation to the computarized analysis of the biomechanics of the bone setting system, moving the use of external fixation equipment towards a less empirical application and in the direction of a greater predictability of its behaviour in function of the loads to which it will be submitted. / Mestre

Lower extremity powered exoskeletons (LEPE) allow people with spinal cord injury (SCI) to perform activities of daily living, such as standing, walking, or stair and ramp ascent/descent. However, current LEPE walk slowly and require extensive use of forearm crutches to maintain user stability. Consequently, this limits LEPE time of use and overall system performance. While the biological ankle is known to be critical for energy efficiency, speed, and stability in able-bodied walking, current LEPE do not include biomimetic ankle designs and thus limit device performance. The objective of this thesis is to determine biomimetic ankle mechanics for a LEPE, thereby defining ankle design requirements that could reduce crutch loads and thus extend LEPE use. Virtual prototyping techniques were used to achieve this objective. Two 3D models of a real LEPE (ARKE, Bionik Laboratories) attached to a human musculoskeletal model were developed and validated. The first model (biomimetic model) was driven by 3D marker kinematics from 30 able-bodied participants walking at four realistically slow LEPE walking speeds. The second model (SCI model) was driven by 3D marker kinematics from five SCI participants walking in the ARKE LEPE with instrumented forearm crutches. Once the models were validated by comparing predicted to measured ground reaction forces (GRF) and centre of pressure (COP) trajectories, biomimetic LEPE ankle design requirements were determined. Ankle range of motion, quasi-stiffness, work, peak moment, and peak power were compared between human and human+ARKE models, across four gait phases and four slow walking speeds. The major findings were: the human+ARKE model had significantly different quasi-stiffness values across all four gait phases; quasi-stiffness increased with increasing speed; the human+ARKE model’s ankle always absorbed net-work, even at the fastest walking speed; quadratic regression was significantly more accurate than linear regression for modelling ankle quasi-stiffness. These results suggested that passive variable stiffness ankles incorporating quadratic elastic spring elements could achieve biomimetic ankle functions and thus potentially increase LEPE user walking speed, stability, and reduce overuse of crutches.

Orientador: Paulo Henrique Ferreira Caria / Tese (doutorado) - Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-16T05:17:07Z (GMT). No. of bitstreams: 1 Prado_FelippeBevilacqua_D.pdf: 2295731 bytes, checksum: b3c79f4fe2cee1adf3eca0dd86f0eed4 (MD5) Previous issue date: 2010 / Resumo: Introdução: As tensões mastigatórias são absorvidas pelos processos alveolares e são dissipadas do pilar zigomático para o restante do crânio. A análise por elementos finitos é útil para avaliar a dissipação da tensão e simular o comportamento mecânico de estruturas biológicas. Objetivo: O Objetivo deste estudo foi analisar a dissipação da tensão principal máxima na região do Pilar Zigomático de um crânio humano, ao simular a oclusão dos molares. Material e Método: Um modelo dos ossos faciais foi construído a partir de imagens tomograficas computadorizadas com 0,25 mm de espessura de um crânio humano dentado pertencente ao Departamento de Morfologia da FOP - UNICAMP. O modelo geométrico foi construído com base na modelagem por meio do software Rhinoceros 4,0 (modelagem tridimensional por superfícies NURBS), utilizando a técnica de BioCAD e software MSC / Nastran ® 4.5 para Windows (The Corporation MacNeal-Schwendler, Savannah, GA, E.U.A.) que reproduziu o modelo de elementos finitos com as propriedades mecânicas da estrutura original. Resultados: Durante a aplicação da carga nos molares superiores, surgiram na superfície interna do seio maxilar duas linhas tensão máxima principal a partir do assoalho do seio maxilar, a primeira em direção ao pilar zigomático e a segunda para a região póstero-lateral do seio maxilar. Na região de transição entre a maxila e a crista zigomático maxilar foi observado uma área de tensão máxima principal nula. Conclusão: A tensão máxima principal durante a oclusão molar não é transferida diretamente ao pilar zigomático, mas sim para estruturas adjacentes. / Abstract: Introduction: Masticatory stress are absorbed by the alveolar processes and dissipated from the Zygomatic Pillar for the hole skull. The finite element analysis is useful to evaluate the stress dissipation and simulate the mechanical behavior of biological structures. Objective: The objective of this study was to analyze the dissipation of maximum principal strain in the region of the Pillar Zygomatic of a human skull during molars occlusion. Material and Methods: A model of the facial bones was constructed from computed tomography images with 0.25 mm thickness of a dentate human skull from the Department of Morphology, FOP - UNICAMP. The geometric model was built based on modeling using the Rhinoceros 4.0 software (three-dimensional modeling by NURBS surfaces), using the technique of BioCAD and MSC / Nastran for Windows ® 4.5 software (The MacNeal-Schwendler Corporation, Savannah, GA USA) which reproduced the finite element model with the mechanical properties of the original structure. Results: During application of the load on the upper molars two lines of maximum principal strain appeared on the inner surface of the maxillary sinus from the maxillary sinus floor, the first toward the Zygomatic Pillar and the second to the posterior of the maxillary sinus. Conclusion: The maximum principal strain during molar occlusion is not transferred directly to the Zygomatic Pillar, but to adjacent structures. / Doutorado / Anatomia / Doutor em Biologia Buco-Dental

Orientador: Paulo Henrique Ferreira Caria / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-17T15:52:01Z (GMT). No. of bitstreams: 1 Freire_AlexandreRodrigues_M.pdf: 1572266 bytes, checksum: 71737a1b0efda969642a5281beaa6ff4 (MD5) Previous issue date: 2011 / Resumo: O tecido ósseo do crânio humano é organizado para estabelecer adaptação à função mecânica. Os ossos que compõem o esqueleto facial formam os pilares de sustentação das forças mastigatórias, sendo que o pilar na região anterior é denominado pilar canino. Teoricamente as tensões mecânicas nesta região se originam no dente canino superior e se dissipam em direção à glabela. O objetivo deste estudo foi avaliar os locais de dissipação e a intensidade das tensões mecânicas no dente canino superior e pilar canino por meio da análise de elementos finitos tridimensional. A partir de cortes tomográficos de 0,25 mm de espessura de um crânio humano, masculino e de aproximadamente 38 anos, foi construído um modelo de elementos finitos formado por 135072 nós e 84157 elementos pelo software Ansys v12. Sobre a margem inferior do osso e arco zigomáticos foi aplicada uma força mastigatória de 200N, simulando a ação do músculo masseter e o suporte foi aplicado no contato oclusal do dente canino superior. Foram analisadas as tensões de Von-mises e máxima principal. As tensões de Vonmises determinaram a dissipação pelo pilar canino, com áreas concentradas na eminência canina e no processo frontal da maxila. A tensão máxima principal mostrou as áreas de compressão no corpo da maxila, processo frontal da maxila, próximo à sutura frontomaxilar e no osso nasal e, tração no processo alveolar e base do processo frontal da maxila. Conclui-se que as tensões se dissipam pelo pilar canino conforme os fundamentos teóricos da biomecânica, de maneira não uniforme com concentração de tensões de tração e compressão em diferentes áreas. / Abstract: The bone tissue of the human skull is organized to provide adaptation to mechanical function. The bones of the facial skeleton form the pillars of support of the masticatory forces, and in the anterior region is called canine pillar. Theoretically, the mechanical stresses in this region originate in the upper canine tooth and dissipate toward the glabella. The aim of this study was to evaluate the sites of dissipation and the intensity of mechanical stresses in the upper canine and canine pillar by tridimensional finite element analysis. From CT images with 0.25 mm thickness of a male human skull, with approximately 38 years, was generated a finite element model, which consists of 13,5072 nodes and 84,157 elements, through of the software Ansys v12. On the inferior margin of the zygomatic bone and zigomatic arch was applied a masticatory force of 200N, simulating the action of the masseter muscle, and a support was applied in the occlusal contact of the upper canine tooth. Were analyzed the Von-mises and maximum principal stresses. The Von-mises stresses determined the stress dissipation in the canine pillar, with areas concentrated at the canine eminence and frontal process of maxilla. The maximum principal stress showed compression areas at the body of the maxilla, frontal process, close to the frontomaxillary suture and in the nasal bone. Tensile stress located on the alveolar process and the base of the frontal process. In conclusion, the stresses were dissipated by the canine pillar as the theoretical principles of biomechanics, not uniformly and with concentration of tensile stress and compression in different areas. / Mestrado / Anatomia / Mestre em Biologia Buco-Dental

Orientador: José Ricardo de Albergaria Barbosa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T21:59:25Z (GMT). No. of bitstreams: 1 Figueiredo_EvandroPortela_M.pdf: 2256697 bytes, checksum: bfe81580a0631a9ffe94d04bf2f85d23 (MD5) Previous issue date: 2012 / Resumo: O objetivo do presente estudo foi avaliar, comparativamente, in vitro, o efeito de diferentes sistemas de implantes, curtos e longos, sob carregamento axial e oblíquo, na distribuição de tensões em modelos fotoelásticos. Foi confeccionado 16 modelos fotoelásticos em resina (Resina Flexível GIII CMR-201 e endurecedor CME-252/ Polipox® Indústria e Comércio Ltda, São Paulo, SP, Brasil), com dimensões de 40 X 50 X 12mm, contendo implantes de sistemas e comprimentos diferentes. Os modelos foram distribuídos em quatro grupos: Grupo I (n=4) - Implante Neodent (longo) 5x11mm; Grupo II (n=4) - Implante Bicon (longo) 5x11mm; Grupo III (n=4) - Implante Neodent (Curto) 5x6mm; Grupo IV (n=4) - Implante Bicon (Curto) 5x6mm. Foram cimentadas aos conectores protéticos (3,5mm de altura), 4 coroas protéticas fabricadas com liga de cromo-cobalto. Para os implantes curtos a prótese apresentou as dimensões de 13mm de altura, 10mm no sentido mésio-distal e 8mm no sentido vestíbulo-lingual. As próteses para os implantes longos apresentaram as dimensões de 8mm de altura, 10mm no sentido mésio-distal e 8mm no sentido vestíbulo-lingual. Aplicou-se cargas axiais e oblíquas (15 graus) de 0,5 Kgf através de uma máquina de teste universal e um polariscópio circular foi utilizado para visualizar as tensões. Os resultados foram analisados, quantitativamente, através do programa Fringes®, em plataforma MATLAB do LPM/ FEMEC/UFU. Todos os implantes curtos apresentaram maiores níveis de tensão que os implantes longos, independente do sistema e da direção do carregamento. Os implantes curtos do sistema Neodent apresentaram maiores níveis de tensão na área cervical, quando comparados à mesma região dos implantes do sistema Bicon, sob carregamento oblíquo. O carregamento oblíquo resultou em maiores níveis de tensão nos implantes curtos do sistema Neodent que o carregamento axial. Dentro dos limites deste estudo conclui-se que implantes curtos estão sujeitos a maior tensão em consequência de cargas, quando comparados aos implantes longos / Abstract: The aim of this study was to compare, in vitro, the role of conventional and short implants of different implant systems, under axial and oblique loading, in stress distribution with photoelastic models. Sixteen models were fabricated with photoelastic resin (GIII Flexible Resin and hardener CMR-201-252 CME / Polipox ® Industria e Comercio Ltda, São Paulo, SP, Brazil), with dimensions 40x50x12 mm, containing different implants systems and different implant lengths. The models were divided into four groups: Group I (n=4) - conventional Neodent implant (5 x 11 mm); Group II (n=4) - conventional Bicon implant (5 x 11 mm); Group III (n=4) - short Neodent implant (5 x 6 mm); Group IV (n=4) - short Bicon implant (5 x 6 mm). Four prosthetic crowns made of cobalt chromium alloy were cimented on the abutments (3.5 mm in height). For the short implants the prosthesis dimensions were 13 mm in height, 10 mm mesiodistally and 8 mm buccolingually. The prosthesis for conventional implants had 8 mm in height, 10 mm mesiodistally and 8 mm buccolingually. Axial and oblique load (15 degrees) of 0.5 kgf was applied by a universal testing machine and a circular polariscope was used to visualize the stress. The results were analysed quantitatively by Fringes® program, in LPM/ FEMEC / UFU MATLAB platform. All short implants had higher stress levels than the conventional implants, regardless of the implant system and the load direction. The short Neodent implants system had higher levels of stress in the cervical third, compared to the same area of the Bicon implants system, under oblique loading. The oblique load resulted in higher levels of stress in the short Neodent implants system than the axial load. Thus, within the limits of this study, short implants are subjected to higher levels of stress as a result of loads when compared to conventional implants / Mestrado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Mestre em Clínica Odontológica

<p> Motion analysis allows for the collection and quantification of movement, and has long been used for the assessment of gait. In more recent years, models have been developed to accurately track the kinematics of the upper extremity, however, current methods are limited due to the small number of validated kinematic models. Over time, multiple models have developed for shoulder joint center (SJC) calculation, however, few are validated, with most difficult to implement. </p><p> Currently, approximately 3.7 million wheelchair users reside in the USA. The repetitive cyclic propulsion pattern required for wheelchair mobility places high loads on the wrist, elbow, and shoulder and often results in overuse injuries with an estimated 30% to 69% prevalence. Quantification of the shoulder complex using 3D kinematics allows for the assessment of ranges of motion, forces, and moments which may allow for better prescription and training, and propulsion biomechanics in wheelchair users. </p><p> Schnorenberg et al. developed and validated a wheelchair model whereby the SJC was calculated using multiple linear regression of the positions of the scapula, clavicle, and humerus. While this model more accurately tracks the glenohumeral joint center as compared to previous models, it requires advanced training and custom Matlab code which limit application for adoption by low resourced clinics and facilities. A simplified model using Visual 3D was developed to allow for local and international clinical and research applications in conjunction with a previously develop low-cost motion tracking system. Motion data during the wheelchair stroke cycle, was obtained using 12 Vicon cameras and Vicon Nexus software. The 3D motion files were processed using both models. </p><p> The wrist joint center and glenohumeral joint center yielded sub 2 mm mean error. While the wrist, elbow, and glenohumeral joints had an average error of less than 10&deg; during the grasp and vertical events. Through the development and validation of a simplified model utilizing Visual3D, upper extremity motion analysis may be easily applied in international and outreach clinics. This work presents new methodology to augment current paradigms for evaluation of wheelchair biomechanics.</p><p>

<p> Databases on ocean lifeguard injuries are scarce and it is likely that available injury data on lifeguards underestimates the prevalence of musculoskeletal injuries in this population. Currently, the prevalence of injuries in California ocean lifeguards is unknown. The purpose of this study was to identify and describe musculoskeletal injuries present in California ocean lifeguards. This study additionally examined the distribution of injury according to several demographic categories. Of the lifeguards who took this survey, 61% stated they have sustained a work-related injury at some point in their career, and 1410 total injuries were reported. Age, years of experience, employment status, and swimming as a method of maintaining fitness for the job were significantly associated the occurrence of injury. Over half of the injuries reported were within the following lower body segments: thigh/knee, lower leg/ankle, and foot. The knee was the most common injury location requiring surgery. Proper identification and treatment of ocean lifeguard injuries should be a priority due to the high prevalence of injury and the unknown potential effects of these injuries on the individuals. If risk factors for injuries in lifeguards can be identified early on in their career, then interventions can be implemented, which may overall reduce future injury rates within this population.</p><p>

<p> Due to the rising number of stroke victims, the demand for reduced cost and effective treatments for recovering patients increases. To offset this need, previous studies introduced robotic assistance to rehabilitation treatments. This study investigates how much robotic assistance affects the patient by analyzing the differences in muscle activity. From the collected experimental data of ten healthy subjects, the results initially inferred that the end position of the reaching movements affected the muscle activity in biceps and triceps only, while the deltoid was not affected. However, after applying ANOVA one-way analyses, robotic assistance was found to have an impact on the deltoid, triceps, and bicep muscles when subjects moved their hands along an indirect trajectory towards nine targets. Meanwhile, only the bicep was affected when subjects moved their arm in a direct path with assistance. Lastly, the impact that the trajectory of the hand movement had on muscle activity was undetermined.</p><p>

<p> Durotaxis is a mechanism of directed cell migration in which cells respond to gradients of extracellular stiffness. While durotaxis has been predominantly characterized in a subset of mesenchymal cells, the potential for cancer cells to durotax has not been well defined. Numerous studies have demonstrated the role of diffusible factors in cancer cell migration and metastasis. However, given the gradual stiffening of many tumor microenvironments, we hypothesized that a durotactic mechanism might also contribute to the migration of cancer cells. We evaluated the durotactic potential of multiple cancer cell lines by employing a stiffness gradient that mirrors the physiological stiffness encountered by cells throughout a variety of tissues. Customized MATLAB software permitted rapid acquisition of positional data for migrating cells. The automation of cell tracking allowed for large sample sizes and therefore a more robust statistical analysis than previously used to evaluate durotaxis. Durotaxis assays identified two glioblastoma lines, a metastatic breast cancer line, and fibrosarcoma line that are responsive to changes in extracellular stiffness. Of interest was our finding that cancer cells showed strong durotactic behavior when occupying the softest region of the stiffness gradient with decreasing responsiveness as cells occupied increasingly stiff regions of the gradient. These observations suggest that durotaxis is influenced by the stiffness of a cell&rsquo;s local environment, with soft substrates increasing durotaxis efficiency in the cancer cell lines evaluated. Furthermore, we determined that PI3K inhibition was sufficient to inhibit glioblastoma chemotaxis but not durotaxis, suggesting that alternative signaling is used to respond to durotactic directional cues. Lastly, we evaluated the protrusion and retraction dynamics of cells on a stiffness gradient and have identified a unique mode of discontinuous migration exhibited by these cells. Based on our observations, we developed a durotaxis model to suggest how discontinuously migrating cells can respond to a gradient by moving towards regions of increasing stiffness.</p><p>