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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Biomechanical Assessment of Normal and Parkinsonian Gait in the Non-human Primate During Treadmill Locomotion

Thota, Anil K. 27 August 2012 (has links)
No description available.
12

EFFECT OF PREDICTABILITY OF IMPOSED VISUAL MOTION ON THE OCCURRENCE OF MOTION SICKNESS

Otten, Edward W. 12 April 2005 (has links)
No description available.
13

The Prediction of Motion Sickness Through People's Perception of Postural Motion

Braun, Jennifer L. 30 November 2012 (has links)
No description available.
14

Níveis de inibição pré-sináptica durante a iniciação do passo em indivíduos com e sem bloqueio da marcha na doença de Parkinson: um estudo transversal / Presynaptic inhibition levels during step initiation in subjects with and without freezing of gait in Parkinson\'s disease: a cross-sectional study

Lira, Jumes Leopoldino Oliveira 06 November 2018 (has links)
Os objetivos deste estudo foram comparar os níveis de inibição pré-sináptica (IPS) durante a iniciação do passo entre indivíduos com doença de Parkinson (DP) com bloqueio motor (BM), sem-BM (S-BM) e indivíduos saudáveis pareados pela idade (ISPI) e, possíveis correlações entre os níveis de IPS com as variáveis comportamentais (amplitude e tempo do ajuste postural antecipatório [APA]) e os escores do New Freezing of Gait Questionnaire (NFOG-Q). A amostra foi composta por 22 indivíduos com BM e 12 S-BM (estágio 3 da DP avaliados no estado on da medicação). Dezesseis ISPI também foram incluídos no estudo. Todos atenderam os critérios de inclusão. Os indivíduos foram avaliados em dois dias. No primeiro dia, todos responderam uma anamnese e o Mini Exame do Estado Mental. Para os indivíduos com DP foi aplicada a escala de estadiamento da DP e a parte III da Escala Unificada de Avaliação da DP (UPDRS) e somente os indivíduos com BM foram avaliados com o NFOG-Q. No segundo dia, todos os indivíduos realizaram a tarefa iniciação do passo na plataforma de força AMTI para avaliação da amplitude e do tempo do APA com ou sem a evocação do reflexo-H na condição teste ou condicionado. O estimulador portátil Nicolet® Viking Quest da CareFusion foi utilizado para evocar o reflexo-H teste e condicionado. O estímulo elétrico foi evocado quando a amplitude do APA ultrapassasse 10 a 20% da linha de base. Todos indivíduos realizaram a tarefa iniciação do passo em 3 condições: 1) sem estímulo; 2) estímulo teste estimulação no nervo tibial; e 3) estímulo condicionado estimulação do nervo fibular antes (intervalo de 100 ms) da estimulação do nervo tibial. Nas três condições, os indivíduos foram instruídos a realizarem 15 passos, logo, 15 estímulos nas condições 2 e 3 de maneira aleatória. A ANOVA one way mostrou diferenças significantes nos valores de IPS entre os três grupos, onde os ISPI apresentaram valores maiores de IPS do que os outros dois grupos e, indivíduos S-BM apresentaram valores maiores IPS comparado aos indivíduos com BM (P<0,001), porém, todos os indivíduos deste último grupo apresentaram facilitação. Adicionalmente, amplitudes maiores e tempos menores do APA foram observados somente para os ISPI (P<0,05), além disso, não foram observadas diferenças entre essas variáveis para os dois grupos de DP (P>0,05). Em relação às correlações, especialmente para os indivíduos com BM, observamos que valores maiores de facilitação estão: fortemente associados com os escores maiores do NFOG-Q (r = -74; P<0,0001); moderadamente associados com as amplitudes menores do APA (r = 0,54; P<0,004); e fracamente associados com os tempos maiores do APA (r = -0,42; P<0,244). Por fim, houve uma forte associação entre as amplitude menores do APA e escores maiores do NFOG-Q (r = -,075; P<0,0001). Em conclusão, indivíduos com BM apresentam facilitação (ausência de IPS) durante a iniciação do passo e associada com deficiências na amplitude e tempo do APA e a severidade do BM. Isso indica que a medula espinhal tem participação na iniciação do passo e pode ser fortemente influenciada por alterações sensório-motoras / The aims of this study were to compare the presynaptic inhibition levels (PSI) in the step initiation between subjects with Parkinson\'s disease (PD) with freezing of gait (FoG), non-FOG (non-FoG), and age-matched healthy controls (HC) and, possible correlations between the PSI levels with the behavioral variables and the New Freezing of Gait Questionnaire (NFOG-Q) scores. Twenty individuals with FoG, 12 individuals with non-FoG (stage 3 of PD assessed in the clinically defined on state), and 16 HC met the inclusion criteria. Subjects visited the laboratory for two days. On the first day, all of the subjects answered the anamnesis and the Mini-Mental State Examination. However, only in the subjects with PD were assessed the severity of disease and the motor symptoms (Unified Parkinson´s Disease Rating Scale part III [UPDRS-III], but the FoG severity was assessed only in the subjects with FoG. On the second day, all of the subjects performed the step initiation on the force platform (AMTI) to assess amplitude and time of anticipatory postural adjustment with or without evoking H-reflex in the test or conditioned condition. The constant-current stimulator (Nicolet® Viking Quest portable EMG apparatus, CareFusion) was used to evoke the H-reflex. The electrical stimulus was evoked when the APA amplitude exceeded 10 to 20% of the baseline. All of the subjects performed the step initiation in 3 conditions: 1) without stimulation of the nerve; 2) test stimulus stimulation of the tibial nerve; and 3) conditioning stimulus - stimulation of the fibular nerve before (100 ms interval) stimulation of the tibial nerve. At three conditions, subjects were instructed to perform 15 steps, thus, 15 stimuli at conditions 2 and 3 in a random order. The ANOVA one way showed significant differences in the PSI values between the three groups, where the ISPI presented higher values of PSI than the other two groups, and S-BM individuals had higher PSI values compared to individuals with BM (P<0.001), however all of the individuals with FoG presented facilitation. In addition, larger amplitudes and smaller times of APA were observed only for ISPI (P<0.05); in addition, no differences were observed between these variables for the two PD groups (P>0.05). In relation to correlations, especially for individuals with FoG, we observed that greater values of facilitation are: strongly associated with the higher NFOG-Q scores (r = -0.74; P<0.0001); moderately associated with the smaller APA amplitudes (r = 0.54; P<0.004); and weakly associated with higher APA times (r = -0.42, P<0.244). Finally, there was a strong association between the smaller APA amplitudes and higher NFOG-Q scores (r = -0.75, P<0.0001). In conclusion, individuals with FoG presented facilitation (absence of PSI) in the step initiation which was associated with deficits in amplitude and time of APA and FoG severity. This indicates that the spinal cord has participation in the step initiation that can be strongly influenced by the abnormal sensory motor
15

Evaluation de l'instabilité posturale à partir d'une plate-forme robotisée de perturbation de l'équilibre / Assessment of postural instability from a robotic balance disturbance platform

Kharboutly, Haissam 23 September 2014 (has links)
Les troubles d’équilibres représentent un problème de santé publique car ils touchent à la mobilité et une partie à l’autonomie. Dans la population gériatrique, les troubles de l’équilibre sont souvent fréquents, de causes multiples et intriquées. Les personnes ayant des atteintes neurologiques, orthopédiques, ou des déficits vestibulaires, peuvent présenter des troubles sensori-moteurs, biomécaniques, ou des problèmes d’intégration sensorielle qui affectent aussi l’équilibre, la posture et donc la mobilité. La question d’identification des différentes déficiences du système d’équilibre est l’objectif de notre travail. Aujourd’hui, la majorité des tests d’évaluation d’équilibre se font en statique et sont très controversés du fait de leur mauvaise répétabilité. Il existe quelques tests d’évaluation de l’équilibre en dynamique, mais ils sont très dépendants de l’outil utilisé. L’évaluation du système d’équilibre devient ainsi de plus en plus compliquée dans le cas dynamique, puisqu’il existe plusieurs plateformes avec différents mouvements. Un patient ne doit pas passer d’une plateforme à une autre pour faire les différents mouvements. Pour une analyse de la stabilité posturale complète, il faut trouver donc une nouvelle solution qui remplace tous les plateformes existantes en une seule plateforme. Cette plateforme originale est l’IsiMove l’outil conçue, développé et utilisé dans cette thèse, pour mesurer la stabilité des sujets ayant des troubles d’équilibre. L’IsiMove est une nouvelle plateforme de perturbation posturale dynamique, conçue par la société AssistMov en collaboration avec l’Institut des Systèmes Intelligents et de Robotique « ISIR » et l’hôpital Rothschild. Cette plateforme répond au besoin de l’analyse de l’équilibre grâce à ses quatre degrés de libertés. La présence des capteurs de forces sur la plateforme permet la mesure de la posture et l’effort d’interaction pied/sol aux cours des réactions de perturbations, ce qui permet l’analyse du comportement pathologique pour une large classe de déficiences motrices, neurologiques ou vestibulaires.Un protocole d’évaluation d’équilibre a été élaboré sous la direction du Pr.Thoumie, suite à une série d’expériences et de tests. Ce protocole est presque complet, il se divise en deux parties : statiques (protocole classique) et dynamiques. La partie dynamique est unique, dans les 3 plans de l’espace, de mouvement simple et de différentes fréquences. Des tests sur des sujets ayant des atteintes neurologiques (myopathie et neuropathie) ou d’accidents vasculaires cérébraux (hémiplégiques) ont été réalisés à l’hôpital Rothschild avec l’aide d’un kinésithérapeute. La majorité des sujets ayant des atteintes neurologiques ont été incapables de réaliser le protocole d’une façon complète, contrairement aux sujets hémiplégiques. Ce qui nous a imposé à proposer deux méthodes d’évaluation de l’équilibre : la première est basée sur une analyse statistique discriminante et la deuxième est basée sur une représentation graphique. / Balance disorders represent a public health problem because they affect mobility and some autonomy. In the geriatric population, balance disorders are often frequent, have multiple causes and intricate. People with neurological, orthopedic or vestibular deficits may have sensorimotor disorder, biomechanical trouble or sensory integration problems that also affect balance, posture and thus mobility.The identification of the different impairments of balance system issue is the goal of our work. Today, the majority of the evaluation tests of balance are in “static” and they are highly controversial because of their poor repeatability. There are some tests for balance evaluation in “dynamic” conditions, but they are very dependent on the used tool. Balance evaluation becomes more complicated in the dynamic case, since there are several platforms with different movements. A patient should not move from one platform to another to make different movements and evaluations. For a complete analysis of postural stability, we must find a new solution that replaces all existing platforms into a single platform. This original platform is “IsiMove” the tool designed, developed and used in this thesis to measure the stability of subjects with balance disorders.IsiMove is a new dynamic posturography platform, designed by ASSISTMOV SAS company in collaboration with the Institute of Intelligent Systems and Robotics "ISIR" and the Rothschild Hospital. This platform addresses the need for balance analysis with its four degrees of freedom. The dual force plate on the platform allows the measurement of the posture and the force interaction of the foot / floor during the reactions, which then allows the analysis of the pathological behavior for a broad class of physical disabilities, neurological or vestibular.A new balance evaluation protocol was elaborated under the direction of Pr.Thoumie, following a series of experiments and tests. This protocol is almost complete; it is divided into two parts: static (standard protocol) and dynamic. The dynamic part is unique, in all 3 planes of space, simple movement and different frequencies. Tests on subjects with neurological disorders (myopathy and neuropathy) or stroke (hemiplegia) were made in the Rothschild hospital with the help of a physiotherapist. The majority of subjects with neurological disorders were unable to perform all exercises protocol, unlike patients with stroke. This has force us to propose two balance assessment methods: the first is based on discriminant statistical analysis and the second is based on graphical representation.
16

Níveis de inibição pré-sináptica durante a iniciação do passo em indivíduos com e sem bloqueio da marcha na doença de Parkinson: um estudo transversal / Presynaptic inhibition levels during step initiation in subjects with and without freezing of gait in Parkinson\'s disease: a cross-sectional study

Jumes Leopoldino Oliveira Lira 06 November 2018 (has links)
Os objetivos deste estudo foram comparar os níveis de inibição pré-sináptica (IPS) durante a iniciação do passo entre indivíduos com doença de Parkinson (DP) com bloqueio motor (BM), sem-BM (S-BM) e indivíduos saudáveis pareados pela idade (ISPI) e, possíveis correlações entre os níveis de IPS com as variáveis comportamentais (amplitude e tempo do ajuste postural antecipatório [APA]) e os escores do New Freezing of Gait Questionnaire (NFOG-Q). A amostra foi composta por 22 indivíduos com BM e 12 S-BM (estágio 3 da DP avaliados no estado on da medicação). Dezesseis ISPI também foram incluídos no estudo. Todos atenderam os critérios de inclusão. Os indivíduos foram avaliados em dois dias. No primeiro dia, todos responderam uma anamnese e o Mini Exame do Estado Mental. Para os indivíduos com DP foi aplicada a escala de estadiamento da DP e a parte III da Escala Unificada de Avaliação da DP (UPDRS) e somente os indivíduos com BM foram avaliados com o NFOG-Q. No segundo dia, todos os indivíduos realizaram a tarefa iniciação do passo na plataforma de força AMTI para avaliação da amplitude e do tempo do APA com ou sem a evocação do reflexo-H na condição teste ou condicionado. O estimulador portátil Nicolet® Viking Quest da CareFusion foi utilizado para evocar o reflexo-H teste e condicionado. O estímulo elétrico foi evocado quando a amplitude do APA ultrapassasse 10 a 20% da linha de base. Todos indivíduos realizaram a tarefa iniciação do passo em 3 condições: 1) sem estímulo; 2) estímulo teste estimulação no nervo tibial; e 3) estímulo condicionado estimulação do nervo fibular antes (intervalo de 100 ms) da estimulação do nervo tibial. Nas três condições, os indivíduos foram instruídos a realizarem 15 passos, logo, 15 estímulos nas condições 2 e 3 de maneira aleatória. A ANOVA one way mostrou diferenças significantes nos valores de IPS entre os três grupos, onde os ISPI apresentaram valores maiores de IPS do que os outros dois grupos e, indivíduos S-BM apresentaram valores maiores IPS comparado aos indivíduos com BM (P<0,001), porém, todos os indivíduos deste último grupo apresentaram facilitação. Adicionalmente, amplitudes maiores e tempos menores do APA foram observados somente para os ISPI (P<0,05), além disso, não foram observadas diferenças entre essas variáveis para os dois grupos de DP (P>0,05). Em relação às correlações, especialmente para os indivíduos com BM, observamos que valores maiores de facilitação estão: fortemente associados com os escores maiores do NFOG-Q (r = -74; P<0,0001); moderadamente associados com as amplitudes menores do APA (r = 0,54; P<0,004); e fracamente associados com os tempos maiores do APA (r = -0,42; P<0,244). Por fim, houve uma forte associação entre as amplitude menores do APA e escores maiores do NFOG-Q (r = -,075; P<0,0001). Em conclusão, indivíduos com BM apresentam facilitação (ausência de IPS) durante a iniciação do passo e associada com deficiências na amplitude e tempo do APA e a severidade do BM. Isso indica que a medula espinhal tem participação na iniciação do passo e pode ser fortemente influenciada por alterações sensório-motoras / The aims of this study were to compare the presynaptic inhibition levels (PSI) in the step initiation between subjects with Parkinson\'s disease (PD) with freezing of gait (FoG), non-FOG (non-FoG), and age-matched healthy controls (HC) and, possible correlations between the PSI levels with the behavioral variables and the New Freezing of Gait Questionnaire (NFOG-Q) scores. Twenty individuals with FoG, 12 individuals with non-FoG (stage 3 of PD assessed in the clinically defined on state), and 16 HC met the inclusion criteria. Subjects visited the laboratory for two days. On the first day, all of the subjects answered the anamnesis and the Mini-Mental State Examination. However, only in the subjects with PD were assessed the severity of disease and the motor symptoms (Unified Parkinson´s Disease Rating Scale part III [UPDRS-III], but the FoG severity was assessed only in the subjects with FoG. On the second day, all of the subjects performed the step initiation on the force platform (AMTI) to assess amplitude and time of anticipatory postural adjustment with or without evoking H-reflex in the test or conditioned condition. The constant-current stimulator (Nicolet® Viking Quest portable EMG apparatus, CareFusion) was used to evoke the H-reflex. The electrical stimulus was evoked when the APA amplitude exceeded 10 to 20% of the baseline. All of the subjects performed the step initiation in 3 conditions: 1) without stimulation of the nerve; 2) test stimulus stimulation of the tibial nerve; and 3) conditioning stimulus - stimulation of the fibular nerve before (100 ms interval) stimulation of the tibial nerve. At three conditions, subjects were instructed to perform 15 steps, thus, 15 stimuli at conditions 2 and 3 in a random order. The ANOVA one way showed significant differences in the PSI values between the three groups, where the ISPI presented higher values of PSI than the other two groups, and S-BM individuals had higher PSI values compared to individuals with BM (P<0.001), however all of the individuals with FoG presented facilitation. In addition, larger amplitudes and smaller times of APA were observed only for ISPI (P<0.05); in addition, no differences were observed between these variables for the two PD groups (P>0.05). In relation to correlations, especially for individuals with FoG, we observed that greater values of facilitation are: strongly associated with the higher NFOG-Q scores (r = -0.74; P<0.0001); moderately associated with the smaller APA amplitudes (r = 0.54; P<0.004); and weakly associated with higher APA times (r = -0.42, P<0.244). Finally, there was a strong association between the smaller APA amplitudes and higher NFOG-Q scores (r = -0.75, P<0.0001). In conclusion, individuals with FoG presented facilitation (absence of PSI) in the step initiation which was associated with deficits in amplitude and time of APA and FoG severity. This indicates that the spinal cord has participation in the step initiation that can be strongly influenced by the abnormal sensory motor
17

Étude des mécanismes neurophysiologiques de l'instabilité posturale dans la sclérose latérale amyotrophique à partir d'un modèle biomécanique de l'initiation de la marche / Neurophysiological mechanisms study of postural instability in amyotrophic lateral sclerosis from a biomechanical model of gait initiation

Feron, Maryse 16 December 2016 (has links)
L'instabilité posturale est souvent observée chez les patients atteints de la sclérose latérale amyotrophique (SLA). Cependant, les mécanismes neuronaux impliqués dans cette instabilité posturale demeurent largement inconnus. Comparés aux patients SLA sans instabilité postural, les patients atteints de SLA avec instabilité posturale présentent des APA altérés avec un déplacement postérieur du centre de pression du pied diminué (CP) et une durée des APA augmentée, la longueur et la vitesse du premier pas sont réduites, enfin, le contrôle postural dynamique est déficitaire avec une diminution spectaculaire de l'indice de freinage. A l'inverse, nous n’observons aucune modification des phases d’anticipation et d’exécution du pas chez les patients SLA sans instabilité posturale comparés aux sujets témoins. Le faible recul du CP au cours de la phase d’anticipation est corrélé positivement de façon significative à l’atrophie de la substance grise du PCC, SPL, PPN et le CN ; et la durée augmentée de la phase d’anticipation est corrélée négativement de façon significative à l’atrophie de la matière grise du AMS et du cervelet. Les réductions de la vitesse et de la longueur du premier pas sont liées de façon significative à l’atrophie de la matière grise dans le PMC, le PPN et le vermis cérébelleux, enfin, l’absence de freinage actif est corrélée à une diminution du volume de la matière grise du CUN. Ces résultats suggèrent que l'instabilité posturale des patients atteints de SLA est causée, au moins en partie, par le dysfonctionnement des régions et des réseaux connus pour être impliqués dans l'initiation de la marche et dans le contrôle de l’équilibre. / Postural instability is frequently reported in Amyotrophic Lateral Sclerosis (SLA) patients. However, the neural mechanisms that contribute to postural instability in SLA patients remain largely unknown. In comparison to both SLA patients without postural instability and controls, SLA patients with postural instability presented an altered anticipatory postural adjustment (APA) phase with a decreased posterior displacement of the center of foot pressure (CP) and a increased APA duration, decreased length and velocity of the first step and deficit of the dynamic postural control with a dramatic decreased braking index. Conversely, the gait initiation was not significantly modified in SLA patients without postural instability in comparison to controls. The reduced posterior CP displacement during the APA was significantly related to reduced grey matter volume of the left PCC, left SPL, right PPN and caudate nucleus, and the increased APA duration to the reduced grey matter volume of the left AMS and right cerebellum. The reduced velocity of the first step was significantly related to a decreased grey matter volume within the left PMC, right PPN and cerebellar vermis and the reduced braking index to decreased grey matter volume of the right CUN. These results suggest that postural instability of SLA patients result, at least partly, from dysfunction of brain regions and networks known to be involved in gait initiation and balance controls in human.
18

Identification of Key Traditional and Fractal Postural Sway Parameters to Develop a Clinical Protocol for Fall Risk Assessment in Older Adults

Bigelow, Kimberly Edginton 05 December 2008 (has links)
No description available.
19

Wearable Proprioception: Designing wearable technology for improving postural instability in Parkinson's Disease

Overhage, Dennis January 2015 (has links)
This report covers the design research process and results of the 9-week Thesis Project I.A hands-on, Research Through Design approach led the project through an iterative process with a focus on creating functional prototypes and validation with experts to answer the research question: How could proprioceptive wearable technology assist in improving the quality of life for patients of Parkinson’s Disease? Within this main question, focus points have been placed on designing for comfort (i.e. wearability) and well-being with attention to aesthetics. The project builds upon the theories of Design for well-being, Embodied Interaction and Wearable technology and is supported by research on proprioception, Parkinson’s Disease, postural instability and sensory stimuli. The result is a series of models, sketches and prototypes and this report covering the process. The final concept and prototype is a system that monitors upper body posture and provides vibro-tactile feedback on strategically placed areas of the body to guide the patient towards the desired posture.
20

Adaptation to Simultaneous Multi-Dimensional Distortions

Littman, Eric Marshall 02 August 2011 (has links)
No description available.

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