Physical Activity and Alzheimer's Disease Measurements, Observations and Subjective Experiences

Cedervall, Y. 2014. Physical Activity and Alzheimer's Disease. Measurements, Observations and Subjective Experiences. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1008. 82 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-8967-0. Gait disturbances such as slow walking speed and step-to-step variability have been reported among people with mild Alzheimer’s disease (AD) and as risk factors for functional decline, dependency, and falls. Additionally, AD-related emotional reactions and decreased initiative can lead to physical inactivity. The aims of this thesis, therefore, were to explore how the ability to be physically active is affected in the early years of AD, and how people with mild AD and their cohabitants reason about physical activity as part of their everyday life. To meet the aims, an approach inspired by mixed methods research was used, covering measurements, observations and subjective experiences. Data were collected from different sources in parallel. Participants with mild AD were recruited at the Memory Clinic, Uppsala University Hospital. In Study I, a case study with two couples in which one member had AD, in-depth interviews and participating interviews were performed. Physical activity such as walking was viewed as a meaningful routine improving well-being. Participants were positive about making adjustments to enable physical activity. In Study II, the 25 participants with AD showed a significant lower walking capacity (10 m comfortable walk test, 6-minute walk test, Timed-up-and-Go test) at baseline compared to controls. The decline continued during the subsequent two years. The influence of a cognitive task on walking was distinct, despite this, participants maintained a health-promoting level of physical activity during the two-year study-period. In Study III, gait testing in the motor laboratory of 21 participants with AD showed a marked impact on gait parameters (e.g. slowed speed, decreased step length) by a cognitive task. Additionally, specific dual-task gait disturbances were frequent. In Study IV, in-depth interviews with 14 participants with AD indicated that physical activity was viewed as a meaningful activity, used as a means to maintain well-being and selfhood, and contributed to continuity in life. In conclusion, walking capacity deteriorates and declines in the early stages of AD. A simple cognitive task can have a substantially negative impact on walking already in mild AD. In contrast, people with AD can also gain “self-promoting benefits” from physical activity beyond the common health-promoting benefits.