The effect of physical and cognitive challenges on walking in younger and older adults

Abstract

Changes in the gait pattern and gait speed are evident in older adults and are thought to occur due to age-related declines in physical and cognitive function. However, most studies describing age-related changes in gait are conducted in level, unobstructed environments. These assessments of gait do not consider the demands encountered when walking in the community. Community ambulation may be more difficult for older adults, as physically challenging environments such as slopes or stairs may be encountered, and individuals often need to perform secondary tasks concurrently while walking. The overarching aim of this thesis was to examine the effect of physical and cognitive challenges on gait in both older and younger adults. This thesis demonstrated that physical and cognitive demands influence gait differently in older compared to younger adults. Specifically, changes in gait speed when walking on an uphill or downhill slope, which are more physically demanding than walking on a level surface, were more strongly associated with age, health status and physical activity levels. Incorporating the 10MWT on a sloped surface will enhance the clinical utility of measuring gait speed to detect changes in healthy ageing. Despite changes in gait speed when walking downhill, older adults were observed to maintain similar inter-joint coordination and variability compared to younger adults during downhill walking. This finding indicated that older adults may only adjust their inter-joint coordination when they have insufficient physical abilities to meet the physical demands of the walking environment. The findings of the dual-task studies (Chapters 5 and 6) demonstrated that both the difficulty of the walking task and attention switching impact task prioritisation in older adults, validating and expanding upon models of task prioritisation. This thesis has demonstrated that the ageing process influences older adults who walk on sloped surfaces and have to perform secondary tasks that require attention switching, which are factors common to real-world environments. These factors may be included as part of assessment and rehabilitation procedures for older adults who walk in the community.

Date of Award	2021
Original language	English