Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Experimental Section Gerontology 2007;53:274–281 DOI: 10.1159/000102938 Postural Sway during Dual Tasks in Young and Elderly Adults Janina M. Prado a Thomas A. Stoffregen b Marcos Duarte a a Neuroscience Program and School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil; b School of Kinesiology, University of Minnesota, Minneapolis, Minn., USA tions in sway during performance of the search task relative to sway during viewing of a blank target. The sway was also reduced for both groups during viewing a near target when compared to a distant target. Conclusions: The results sug- gest that, despite the overall increase in postural sway with aging, subtle integration of visual information by the pos- tural control system is not affected by aging. The present results support the idea that dual tasks do not necessarily lead to an increase in postural sway. This effect, found here in elderly adults, raises questions about widely held views in which age-related changes in postural sway are related to competition between postural control and other activities for central processing resources. Copyright © 2007 S. Karger AG, Basel Introduction Control of the balance in upright standing is not an automatic task mediated entirely by reflexes. Instead, it depends on a complex and active control system. Older adults tend to sway more and rely more on visual infor- mation to maintain balance, as revealed by laboratory studies employing quiet (unperturbed) and dynamic (perturbed) posturography [1–3]. Such age-related changes have been interpreted as degradation in pos- tural control and have been attributed to decreases in sensory or motor system functions or in cognitive tasks [3, 4] . Key Words Balance  Aging  Posturography Abstract Background: Previous studies have shown that healthy young adults are able to decrease their standing postural sway when an additional postural visual task, such as read- ing, is performed. Objective: In this study, we investigated postural sway during dual tasks in young and elderly adults. Methods: Twelve healthy active elderly adults (aged 65–75 years) and 12 healthy young adults (aged 22–39 years) par- ticipated in the study. The subjects performed different vi- sual tasks while standing on a force plate. We varied the na- ture of the visual tasks (looking at a blank target versus a visual search task) and the distance of visual targets (near versus far). Center of pressure displacement obtained from the force plate data and kinematics of body segments ob- tained from a video analysis system were investigated. Re- sults: Both groups presented significantly larger postural sway in the mediolateral direction during the eyes-closed condition as compared with the eyes-open condition. In the anteroposterior direction, this effect was observed only for the elderly group. Both groups had the same percentage correct in counting letters, but the elderly adults were sig- nificantly slower as compared with the young adults. The amplitude of postural sway was greater for the elderly adults than for the young adults in all conditions. However, both the young and the elderly adults exhibited significant reduc- Received: March 6, 2007 Accepted: March 18, 2007 Published online: May 16, 2007 Marcos Duarte Escola de Educação Fisica e Esporte, Universidade de São Paulo Av. Prof. Mello de Moraes, 65 São Paulo – SP 05508-030 (Brazil) Tel./Fax +55 11 3812 6123, E-Mail mduarte@usp.br © 2007 S. Karger AG, Basel 0304–324X/07/0535–0274$23.50/0 Accessible online at: www.karger.com/ger