Menant, JC and St George, RJ and Sandery, B and Fitzpatrick, RC and Lord, SR, Older people contact more obstacles when wearing multifocal glasses and performing a secondary visual task, Journal of the American Geriatrics Society, 57, (10) pp. 1833-1838. ISSN 0002-8614 (2009) [Refereed Article]
Copyright 2009, Copyright the Authors
Objectives: To determine whether wearing multifocal glasses affects obstacle avoidance and eye and head movements during walking with and without a secondary visual task in older people.
Design: Randomized order, cross-over, controlled comparison.
Setting: Falls laboratory, medical research institute.
Participants: Thirty community-living adults aged 65 and older.
Measurements: Obstacle contacts, secondary-task errors, average head angle (HA) in pitch, and peak-to-peak pitch amplitude of the eye (PA-E) and the head (PA-H) were assessed during obstacle-only and dual-task trials that required participants to read a series of letters presented in front of them at eye level under multifocal and single-lens glasses conditions.
Results: When wearing multifocal lens glasses, participants performed the obstacle-only trials more slowly (P = 0.004) and contacted more obstacles in the dual-task trials (P = 0.001) than when wearing single-lens glasses. For the dual task trials under the multifocal glasses condition, greater PA-E was associated with more obstacle contacts (ρ = 0.409, P = 0.02) and greater PA-H was associated with more secondary-task errors (ρ = 0.583, P = 0.002). Lower HA was associated with more secondary-task errors (ρ = 0.608, P = 0.002) and increased PA-H (ρ = 0.426, P = 0.02).
Conclusion: The findings demonstrate that older adults contact more obstacles while walking with their attention divided when wearing multifocal glasses. This is probably because of a failure to adopt a compensatory increase in pitch head movement, resulting in blurred vision of obstacles viewed through the lower segments of multifocal glasses.
|Item Type:||Refereed Article|
|Keywords:||gait, dual-task, aged|
|Research Division:||Medical and Health Sciences|
|Research Group:||Human Movement and Sports Science|
|Research Field:||Motor Control|
|Objective Group:||Clinical Health (Organs, Diseases and Abnormal Conditions)|
|Objective Field:||Neurodegenerative Disorders Related to Ageing|
|Author:||St George, RJ (Dr Rebecca St George)|
|Web of Science® Times Cited:||18|
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