Axial rotation is regarded as an essential movement of the trunk that allows many individuals to participate in vocations, sports and activities of daily living. Unfortunately when the destabilising nature of rotation is combined with that of spinal flexion, the risk of injuring the spine can increase significantly. Few studies have investigated the potential benefits that maximizing trunk rotation has in certain vocation and sport-related arenas and none have looked at whether adopting certain spinal postures in the sagittal plane can maximise trunk rotation more than others. The aim of the study was to determine the effects of alterations of trunk inclination, spinal posture, pelvic fixation and turning direction on the active range of motion (ROM) of trunk rotation. Twenty healthy individuals participated in the main study. Retro-reflective markers were placed on key anatomical locations and used to track the movement of the thorax and pelvis during a series of repeated maximal trunk rotations in ten different spinal positions within the sagittal plane. Trunk kinematics and kinetics were recorded simultaneously using an optoelectronic motion analysis and force platform measuring system. A repeated-measures multiple analysis of variance (MANOVA) was used to test for the main effects of trunk inclination, spinal posture, fixation of pelvis and direction of turn on maximum active ROM of trunk rotation, maximum pelvic rotation and the anterior-posterior and lateral displacement of the centre of pressure (COP). To investigate test-retest reliability, ten participants were tested on two separate days. Repeatability for each outcome measure was investigated using interclass correlation coefficients (ICC) and Bland Altman graphs. The majority of subjects showed reasonable test-retest reliability for trunk rotation measures in each of the test positions, with ICC’s ranging between 0.562 – 0.731. Overall, trunk inclination (0°, 22.5°, 45°) forward in the sagittal plane had a significant effect on trunk and pelvic rotation (p<0.001) and lateral displacement of the COP (p<0.005) during trunk rotation. As trunk inclination increased from 0° to 45° there was an average increase in trunk rotation ROM of approximately 10 % (approximately 3.4°). Furthermore, increasing trunk inclination led to an increase in lateral displacement of the COP and a decrease in pelvic rotation. Spinal posture (neutral, flexed, extended) at a forward inclination of 45° had a significant effect on trunk rotation (p<0.01) and pelvic rotation (p<0.05), with a neutral spine averaging approximately 3 % (approximately 1.1°) more trunk rotation than a flexed or extended posture. The position and posture of the spine in the sagittal plane appears to have a significant influence on ranges of trunk rotation. The study suggests that rotating the trunk when adopting a neutral spine inclined to 45° will maximise range of trunk rotation and encourage a natural stabilisation of the lower body. This posture meets the unique set of biomechanical requirements for the sport of golf and may help to reduce the risk of injury in manual material handling tasks. Conversely, rotating the trunk whilst the thoracolumbar spine is flexed leads to a reduction in trunk rotation ROM, encourages greater pelvic and lower body rotation, reduces torque production of the trunk and may increase the risk of lower back injury. These findings have important implications in relation to the teaching of spinal position during vocations, sports and activities of daily living that seek to maximise trunk rotation.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Dissertation (Ph.D.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 115 pages. Includes vita. Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1984.

Thesis (M.S.)--University of Michigan, 1984.

No description available.

Thesis (MScEng (Industrial Engineering))--Stellenbosch University, 2008. / In the context of intervertebral disc replacement and customized implants, human simulation studies are of great importance. Simulation models need input data. This study investigated different in vivo motion capturing methods to capture spinal kinematics that will serve as input for simulation models. Available scanning and motion capturing techniques for capturing cervical kinematics range from simple clinical methods, to expensive specialized equipment and software. With a variety of technologies comes a variety of applications. In this study the focus is on capturing the kinematics of the cervical spine. An important distinction was made between two types of motion capturing technologies: external motion capturing and internal imaging technologies. The available external motion capturing technologies pose many advantages in terms of cost, safety, simplicity, portability and producing accurate three dimensional position and orientation. However, the ability for external motion capturing technologies to give accurate information on the movements at each vertebral level is doubted by critics reasoning that the true vertebral motion is concealed by the skin and soft tissue. Although it would be ideal to use external motion capturing systems, one needs to be confident that these surface markers or sensors truly reflect the vertebral motion at each vertebral level. An empirical study was conducted to evaluate the relationship between motion captured on the skin surface and motion of the vertebrae. Twenty-one subjects received low dosage X-rays, while radio opaque markers were attached to the skin at each respective vertebral level. The motion of external markers and that of the vertebrae could be seen simultaneously on one medium. In the empirical study, two outputs were achieved. Firstly, intervertebral kinematic data, for use in further simulation studies was obtained. Secondly, the relationship between surface markers and vertebrae in different motion instances was investigated. Distance and angle parameters were constructed for vertebral prediction from skin surface markers. The causes of variation in these parameters were identified by investigating the correlations of these parameters with anthropometrical variables. Strong correlations of the parameters were observed in flexion, but in extension, especially full extension, the correlations were poor to insignificant. It was concluded that in neutral, half flexion and full flexion it is possible to predict the vertebral position from surface markers by using the parameters and anthropometrical variables. In half extension this prediction would be less accurate and in full extension alternative methods should be investigated for external motion capturing.

Orientador: Ricaro Cardoso Benine / Resumo: A subfamília Stethaprioninae foi proposta por Eigenmann, 1907, e é distinguido dos demais representantes de Characidae por apresentar porte pequeno, corpo alto e comprimido, com um espinho ósseo localizado à frente do primeiro raio da nadadeira dorsal e pela presença de ganchos ósseos distribuídos de maneira assimétrica na nadadeira anal de machos maduros; esses dois últimos caracteres parecem ser sinapomórficos e sustentam a monofilia do grupo. A revisão taxonômica das espécies de Stethaprioninae foi realizada, e nove espécies novas foram descritas por meio da análise de material depositado em coleções ictiológicas. As descrições foram feitas a partir da análise de aproximadamente 2.500 exemplares, dos quais foram tomadas 44 variáveis morfométricas e 14 merísticas, além de dados osteológicos e padrão de colorido. Como resultados, foram consideradas válidas e redescritas 13 espécies: Poptella brevispina, P. compressa, P. longipinnis, P. paraguayensis, Orthospinus franciscensis, Stethaprion erythrops, S. crenatum, Brachychalcinus copei, B. nummus, B. Orbicularis, B. parnaibae, B. retrospina, e B. reisi; além da descrição de nove novas espécies. Orthopinus é um gênero monotípico e endêmico da bacia do rio São Francisco. Stethaprion apresenta duas espécies distribuídas na bacia do rio Amazonas e foi acresentado em nosso trabalho uma nova característica autapormórfica desse gênero, que é a presença de escamas na nadadeira adiposa. Para Poptella, foram diagnosticadas sete espécies... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The subfamily Stethaprioninae was proposed by Eigenmann, 1907, and is distinguished from the other representatives of Characidae because of its small size, tall, compressed body, and a bony spine located in front of the first ray of the dorsal fin and the presence of bony hooks distributed asymmetrical way in the anal fin of mature males; these last two characters are synapomorphic and support the group monophyly. The taxonomic revision of the species of Stethaprioninae was carried out, and nine new species were described through the analysis of deposited material in ichthyological collections. The descriptions were made from the analysis of approximately 2,500 specimens, of which 44 morphometric and 14 meristic variables were taken, in addition to osteological data and color pattern. As a result, 12 species were redescribed: Poptella brevispina, P. compressa, P. longipinnis, P. paraguayensis, Orthospinus franciscensis, Stethaprion erythrops, S. crenatum, Brachychalcinus copei, B. nummus, B. orbicularis, B. parnaibae,B. retrospina, and B. reisi, in addition to the description of ten new species. Orthospinus is a monotypic and endemic genus of the São Francisco river basin. Stethaprion presents two species distributed in the basin of the Amazon River, and is characterized mainly by the presence of scales in the adipose fin, being indicated in our work as an autopormorphic feature of this genus. For Poptella, seven new species were diagnosed, of which three are distributed in t... (Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:28:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-13Bitstream added on 2014-06-13T19:37:19Z : No. of bitstreams: 1 lemos_ff_me_guara.pdf: 3167749 bytes, checksum: 900a2570260a39cccd178d8a2ecb5b4a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Para melhor entender os mecanismos degenerativos da coluna vertebral e avaliar o melhor método para seu tratamento é necessário que se conheça o comportamento dos diversos componentes das articulações intervertebrais. Com isso, torna-se essencial o desenvolvimento de dispositivos capazes de simular as condições fisiológicas de movimentos e cargas a fim de realizar testes in vitro que fornecerão dados para posteriormente serem testados in vivo. O objetivo deste trabalho é o desenvolvimento de dispositivos para a realização de testes in vitro com coluna vertebral. Estes dispositivos constam de uma máquina capaz de simular o movimento de flexão-extensão, pré-cargas axiais e a angulação pélvica, e uma lâmina de extensometria para captar as deformações dos tecidos testados. Foram realizados experimentos com discos invertebrais suínos a fim de avaliar a eficiência dos dispositivos. Realizaram-se dois experimentos usando os dispositivos desenvolvidos e um experimento na máquina universal de ensaios. Como resultado obteve-se valores de propriedades mecânicas coerentes com a literatura e o disco intervertebral comportando-se como um material viscoelástico. Outro ponto importante foi a obtenção da pressão intradiscal aproximada relacionando-a com o deslocamento angular da coluna. Conclui-se que os dispositivos apresentaram funcionamento satisfatório, abrindo perspectivas para outros estudos. / The best way to understand the degenerative mechanisms of the vertebral column and to evaluate appropriated methods for its treatment it is necessary to know the behavior of the diverse components of the intervertebral joints. So, it becomes essential to simulate the physiological conditions of movements and loads in order to carry through test in vitro that they will supply datas to be tested in vivo. The objective of this study is the development of devices of low cont for the accomplishment of tests in vitro with spine. These devices consist of a machine capable to simulate the movement of flexion-extension, daily pay-loads and the pelvic inclination, and an extensometry blade to catch the deformations of tested structures. POrcine had been carried through experiments with intervertebral discs in order to evaluate the efficiency od the devices. Two experiments had been become fullfilled using the developed devices and an experiment in the universal test machine. As result we got values of coherent mechanical properties with literature and the intervertebral disc behaving as a viscoelastic material. Another important point was the attainment of the intradiscal pressure approached relating it with the angular displacement of the spine. It is concluded that the devices had presented satisfactory functioning, opening perspective for other studies.

Les traumatismes du rachis incluent des fractures osseuses, des lésions disco-ligamentaires et des blessures médullaires. Ils impliquent un fort coût pour le système de santé, ainsi qu’une prise en charge (durée d’hospitalisation, atteinte de l’intégrité physique) lourdement handicapante pour leurs victimes. Les séquelles peuvent aller d’une déformation du profil sagittal à la tétraplégie. Leurs causes principales sont les accidents véhicules moteurs, les chutes et les accidents sportifs. Il existe de multiples mécanismes d’apparition des fractures vertébrales (compression, flexion-extension, cisaillement, torsion) et des blessures médullaires (contusion, traction, cisaillement), ce qui rend leur étude complexe. Malgré l’important investissement mis dans la recherche à ce sujet, des lacunes persistent dans la compréhension de ces traumatismes, qui ralentissent la progression des dispositifs de protection du rachis, et le développement des techniques chirurgicales. Dans ce contexte, l’objectif principal de ce doctorat est d’améliorer la compréhension fondamentale des mécanismes de fractures vertébrales et des blessures de la moelle épinière. Une première partie du travail a visé à développer des connaissances fondamentales sur les propriétés géométriques et mécaniques des vertèbres et de la moelle épinière. Ce type de propriétés a été utilisé pour créer et calibrer un modèle par éléments finis du rachis thoracolombaire. Ce modèle a ensuite été utilisé pour étudier le lien entre chargements mécaniques et une classification clinique des patrons de fractures vertébrales, ainsi que l’effet de différents éléments d’influences sur la mécanique de la contusion médullaire. / Spine traumas include bony fractures, intervertebral disc and ligaments lesions, and spinal cord injuries. They imply a high cost for the health system, as well as a highly incapacitating surgical management (length of hospitalization, physical handicap), and result in aftereffects such as sagittal curve deformity or tetraplegia. Their principal causes are motor vehicle accidents, falls and sports accidents. Multiple mechanisms of occurrence exist for vertebral fractures (compression, flexion-extension, shear, torsion) and spinal cord injury (contusion, traction, shear), which makes them complex to study. Despite major investments in research on this topic, there is a lack of the understanding of some aspects regarding these traumas. This slows down the progress in protection devices and surgical strategies development. In this context, the main objective of this Ph.D. is to improve fundamental knowledge of vertebral fractures and spinal cord injuries mechanisms. A first part of this work has been to develop fundamental knowledge on geometrical and mechanical properties of the vertebrae and the spinal cord. This type of properties has been used to create and calibrate a finite element model of the thoracolumbar spine. This model was then used to study the link between mechanical loadings and a clinical classification of vertebral fracture patterns, as well as the effect of various parameters on spinal cord contusion mechanisms.