Understanding the determinants of independent mobility in older adults

Abstract

As aging occurs, safely maintaining an active lifestyle is critical for health and independence. Independent mobility is influenced by one’s ability to perform three essential tasks of daily living: transitioning from a seated to standing posture, maintaining upright stance and walking. In spite of the apparent similarities in the predictive utility of these different tasks, there are few studies that have explored the specific relationship between these tasks that define independent mobility within individuals to determine if they reflect unique challenges to control. The thesis focused on two studies to advance understanding of the determinants of independent mobility in older adults. Study 1 explored the association between measures of standing, transitions and walking in 28 older adults. An important element was the assessment using portable low-cost measurement technology (Wii force boards and wearable accelerometers) so that testing could be done in the community. The results of this study revealed the potential importance of sit-to-stand performance as an independent measure of function in older adults. One important outcome was the need for a more detailed measurement of the sit-to-stand task, which is characterized by different phases that have unique control challenges. As a result, Study 2 was designed to evaluate different measurements of the sit-to-stand phases in order to provide a measurement tool that could be used in community and clinical testing. Ground reaction forces were found capable of identifying the different sit-to-stand phases and therefore afford the ability to quantify this behavior using portable technology. Identifying the underlying control mechanisms and relationships between these mechanisms allows clinicians to prescribe targeted and potentially more effective interventions focused on behavior specific control challenges.