L’étude de l’équilibre orthostatique a fait l’objet de nombreuses études s’attachant à l’analyse des déplacements du centre des pressions comme indicateur de l’efficience du contrôle postural. Plus particulièrement, une large littérature se concentre sur l’étude des mesures stabilométriques notamment en lien avec l’avancée en âge. En effet, le vieillissement s’accompagne généralement d’une altération du système postural pouvant avoir diverses conséquences telles que l’occurrence de chutes. Jusqu’à présent, la caractérisation des effets de l’âge sur la stabilité posturale à partir des mesures stabilométriques reste limitée par la nature même des paramètres utilisés. Dans ce travail, nous proposons l’utilisation de nouvelles méthodes issues de la théorie des systèmes dynamiques pour définir des signatures posturales propres à l’avancée en âge. Ces méthodes s’appuient sur l’analyse de la structure temporelle des fluctuations posturales et peuvent fournir une information sur leur degré de complexité. Pour ce faire, cinq études ont été réalisées. L’étude 1 a montré que le vieillissement affecte de manière significative la dynamique des déplacements du centre des pressions. Plus précisément, une personne âgée oscille de manière plus importante et avec une structure temporelle des oscillations posturales différentes d’un sujet jeune. Les études 2 et 3, à caractère méthodologique, renforcent l’hypothèse d’un caractère stochastique, et donc non chaotique, de la dynamique des déplacements du centre des pressions. Ces deux études ont également permis de développer et de tester deux paramètres dynamiques apportant chacun une information différente sur la structure des fluctuations posturales. L’étude 4 a montré que les mesures dynamiques et stabilométriques sont complémentaires et que certaines ont une sensibilité à l’âge. Elle suggère également que les différentsparamètres dynamiques ne sont pas forcément redondants. L’étude 5 explore l’effet d’un entrainement de trois mois, sollicitant notamment les capacités d’équilibration, sur la structure dynamique des oscillations posturales de la personne âgée. / The study of postural balance has been the subject of numerous studies focusing on the analysis of the pressure center displacement as an indicator of postural control efficiency. Specifically, a large literature focuses on the study of stabilometric measures particularly in relation with age advancing. Indeed, aging coincides with the deterioration of the postural system and its functional consequences, one of which is the fall. Until now, the characterization of the effects of age on postural stability of stabilometric measures has remained limited by the nature of the parameters used. In this work, we propose the use of new methods from dynamical system theories to define postural signatures in relation with aging. These methods are based on the analysis of the temporal structure of postural fluctuations and can provide information on their degree of complexity. Five studies have been conducted. Study 1 showed that aging significantly affects the dynamics of displacements of the pressure center. More precisely, a senior’s measures show a significant difference in the temporal structure compared to a young subject. Studies 2 and 3, more particularly focused on methodology, reinforcing the hypothesis of a stochastic nature of the dynamics (and therefore not chaotic) of postural oscilations. These two studies also allowed to develop and test two dynamical parameters, each providing different information on the structure of postural fluctuations. Study 4 showed that the dynamical and stabilometric measures are complementary and are influenced by age. This study has underlined the non-redundancy of information from each dynamical parameter. Study 5 explored the effect of a three-months training, including specific balance exercises, on the dynamical structure of postural sway of the elderly

名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成4年12月22日 市川真澄氏の博士論文として提出された

Socio-economic status form a big part of each person's physical development. Socio-economic status is defined by house income, house standards, family size, physical activity level and parents education level and occupation. Socio-economic status influence posture as well as physical activity levels of adolescents. Adolescents living in low socio-economic areas show delayed growth with an influence on posture. Posture is mainly influenced by genetics as well as some socio-economic variables such as diet, malnutrition en obesity. Posture development is also related to physical activity. A sedentary lifestyle is more common under adolescence in low socio-economic areas than those in high socio-economic areas. This incidence can be due to the fact that a lack of equipment and safety are more common in low socio-economic areas, subsequently the lack of organised physical activity. The benefits of physical activity are endless and should be integrated as part of our daily living. Different studies of socio-economic status, physical activity and posture deformities were found although none compared all three valuables with each other. Literature is only used as a guideline and not for a comparison with this study. The goal of this study was firstly to determine the influence of socio-economic status on posture deformities on black African adolescence and secondly to determine the influence of socio-economic status on physical activity levels of black African adolescence. A total of 251 pupils participated in the study. Questionnaires were completed on socio-economic status as well as on physical activity levels. Posture screening was done according to the New York posture test and a posture grid. Pupils were evaluated from anterior, posterior and lateral sides together with evaluation of foot deformities and a more defined scoliosis screening by the Adams forward bending test. The prevalence of posture deformities and insufficient organised physical activity are high in black African adolescence. The most common posture deformity is lordosis (84%) and a protruding abdomen (67%). These deformities are closely correlated to socio-economic status especially diet because it influences growth and development of children. Physical activity levels are influenced by a lack of transport and organised physical activities. A total of 87,5% of pupils use walking as transport, based on which can conclude that little time is left for organised physical activity. Socio-economic status does have an influence on posture and participation in physical activity. / Thesis (M.Sc. (Human Movement Science))--North-West University, Potchefstroom Campus, 2009.

Socio-economic status form a big part of each person's physical development. Socio-economic status is defined by house income, house standards, family size, physical activity level and parents education level and occupation. Socio-economic status influence posture as well as physical activity levels of adolescents. Adolescents living in low socio-economic areas show delayed growth with an influence on posture. Posture is mainly influenced by genetics as well as some socio-economic variables such as diet, malnutrition en obesity. Posture development is also related to physical activity. A sedentary lifestyle is more common under adolescence in low socio-economic areas than those in high socio-economic areas. This incidence can be due to the fact that a lack of equipment and safety are more common in low socio-economic areas, subsequently the lack of organised physical activity. The benefits of physical activity are endless and should be integrated as part of our daily living. Different studies of socio-economic status, physical activity and posture deformities were found although none compared all three valuables with each other. Literature is only used as a guideline and not for a comparison with this study. The goal of this study was firstly to determine the influence of socio-economic status on posture deformities on black African adolescence and secondly to determine the influence of socio-economic status on physical activity levels of black African adolescence. A total of 251 pupils participated in the study. Questionnaires were completed on socio-economic status as well as on physical activity levels. Posture screening was done according to the New York posture test and a posture grid. Pupils were evaluated from anterior, posterior and lateral sides together with evaluation of foot deformities and a more defined scoliosis screening by the Adams forward bending test. The prevalence of posture deformities and insufficient organised physical activity are high in black African adolescence. The most common posture deformity is lordosis (84%) and a protruding abdomen (67%). These deformities are closely correlated to socio-economic status especially diet because it influences growth and development of children. Physical activity levels are influenced by a lack of transport and organised physical activities. A total of 87,5% of pupils use walking as transport, based on which can conclude that little time is left for organised physical activity. Socio-economic status does have an influence on posture and participation in physical activity. / Thesis (M.Sc. (Human Movement Science))--North-West University, Potchefstroom Campus, 2009.

Thesis (M.S.)--University of Michigan, 1986. / "A research report submitted in partial fulfillment of the requirements for the degree ..."

Thesis (M.S.)--University of Michigan, 1987.

Thesis (M.S.)--University of Michigan, 1986. / "A research report submitted in partial fulfillment of the requirements for the degree ..."

Thesis (M.S.)--University of Michigan, 1967.

Thesis (M.S.)--University of Michigan, 1987.

Thesis (M.S.)--University of Michigan, 1967.