Does trunk acceleration variability during walking improve for elderly people following cataract surgery?

Abstract

Background; Increased trunk acceleration variability during gait may be considered as a sign of impaired dynamic postural stability. Vision is an important factor in maintaining postural stability during walking, and impaired vision has been shown to influence trunk acceleration variability. Purpose; The aim of this study was to examine the long-term effects of cataract surgery on trunk acceleration variability during walking, in comparison to a vision-healthy control group. Material and method; Trunk acceleration variability was investigated before and 12 months after cataract surgery, to detect changes over time and compare these between the groups. One hundred and four older adults (mean age 78.4 years, SD 4.9) undergoing cataract surgery and fifty-three vision-healthy, older controls (mean age 80.8 years, SD 3.8) were included in this study. Participants performed timed walking at preferred and fast gait speeds, and in two lighting conditions; normal and subdued, and trunk accelerations in three dimensions were measured during walking using a triaxial accelerometer. Trunk acceleration variability was calculated by using an unbiased autocorrelation procedure. Results; In normal light at preferred gait speed there were significant differences in the changes between the cataract and the control group in all directions; AP (p=0.01), V (p<0.01), and ML (p<0.01). In fast gait speed no significant differences in the changes between the two groups were detected. In subdued light a similar pattern was found with significant differences in the changes between the two groups in preferred gait speed; (AP (p=0.01), V (p<0.00), and ML (p<0.00); but only a significant difference in the change in the vertical direction during fast gait speed. Conclusion; The findings of this study suggest that patients improve their postural stability during walking during the year following cataract surgery. Relevance Postural stability amongst the elderly population is a complex challenge, and a topic that is highly relevant to persons working with rehabilitation or to prevent a drop in daily functioning for elderly. Knowledge to understand the relative role of vision correction in maintenance of postural stability (balance during walking) is important, because of the complex inter-relations between vision and trunk motion during gait, which is important for daily functioning and falls risk. With an increasing elderly population in Norway, knowledge of this will be important to prevent accidents, but also in order to prevent increasing costs following a fall and thereby an increased need for help in daily life.