Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Health and Rehabilitation Sciences

Supervisor

Dr. Anthony Vandervoort & Dr. Gareth Jones

Abstract

The overall aim of this thesis was to provide a more focused understanding about the physical function of older women across levels of frailty. The specific aims were: 1) Examine the physical function of older women across levels of frailty during performance-based tasks and throughout their normal daily life; and 2) Review the effectiveness of current exercise interventions for the management of frailty. To answer these aims an observational study of community-dwelling older women (63-100 years) from rural Greece and a comprehensive systematic review on the impact of exercise on frail older adults were conducted. The performance-based measures that had the strongest association with frailty were ambulatory mobility, lower body muscular endurance, and non-dominant handgrip strength. Walking at a preferred pace was more related to frailty than walking at maximal pace and grip strength of the non-dominant hand had a stronger association with frailty compared to the dominant hand. In addition, accelerometers showed good agreement with the other physical activity tools, had the strongest association with frailty, and could be used to dissociate levels of frailty. This thesis showed that multiple methods can be used to accurately determine the duration and intensity of physical activity in older adults across levels of frailty since each method examined in this thesis had limitations but provided useful information about different aspects of physical activity. Muscle activity and quiescence, as measured with portable electromyography, may add insight to the dissociation of frailty since they differ across levels of frailty and may also be used to indicate differences between the upper and lower body muscles. Finally, the systematic review indicated that structured exercise training can have a positive effect on frail older adults and thus can be helpful for the management of frailty. Multicomponent training interventions, of long duration (≥ 5 months), performed three times per week, for 30-45 minutes per session, generally had superior outcomes than other exercise programs. The findings from this thesis indicated that the criteria selected to define frailty and the measurement protocols for these criteria are important. Future investigations will help classify the potential role of these measures in preventing further functional decline.


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