부산대학교 도서관

There are clear recommendations regarding the amount of physical activity necessary for achieving health benefits and reducing the risk of chronic disease in able-bodied humans. However, there is a paucity of empirical evidence to inform the development of equivalent guidelines for various disabled populations. In order to better understand the role of physical activity in the health and wellbeing of wheelchair users, the logical foundation was to develop valid and reliable methods to accurately quantify physical activity. Therefore, the initial aim of this thesis was to assess the validity of objective wearable technologies in the prediction of physical activity energy expenditure (PAEE). Chapter 3 identified the wrist as the most appropriate anatomical location to wear a tri-axial accelerometer during outdoor wheelchair propulsion. In Chapter 4, a device comparison study was conducted in a controlled laboratory environment, using bespoke PAEE prediction equations, developed for this population. Mean absolute error for devices worn on the wrist were lower for the GENEActiv (21%) device compared to GT3X+ (33%), across all activities. Using a multi-sensor Actiheart device, the absolute prediction error was further reduced when an individual heart rate calibration was applied (16.8%), compared to a generic system calibration (51.4%) (Chapter 6). Incorporating accelerometry and physiological signals with individual calibration seemingly offered an improvement in the prediction of PAEE in wheelchair users. This rigorous method development process permitted the habitual monitoring of free-living physical activity behaviour, during a home-based moderate-intensity exercise intervention in persons with chronic paraplegia. In comparison to a lifestyle maintenance control group, the intervention group completed a 6-week arm crank ergometry intervention, exercising 4 times per week for 45 minutes at 60 – 65% V̇O2 peak. The intervention improved fasting markers of insulin resistance, increased fasting fatty acid oxidation, and cardiorespiratory fitness. There were also positive changes in health and wellbeing constructs and an excellent compliance rate. Hence, home-based upper body exercise may have the potential to be used as a long-term behavioural strategy to improve the health and wellbeing of persons with chronic paraplegia.