Bridging the Gap between Clinical and Behavioural Gerontology Part I: Promoting Late-Life Mobility and Independence

Walking is a complex motor task generally performed automatically by healthy adults. Yet, by the elderly, walking is often no longer performed automatically. Older adults require more attention for motor control while walking than younger adults. Falls, often with serious consequences, can be the result. Gait impairments are one of the biggest risk factors for falls. Several studies have identified changes in certain gait parameters as independent predictors of fall risk. Such gait changes are often too discrete to be detected by clinical observation alone. At the Basel Mobility Center, we employ the GAITRite electronic walkway system for spatial-temporal gait analysis. Although we have a large range of indications for gait analyses and several areas of clinical research, our focus is on the association between gait and cognition. Gait analysis with walking as a single-task condition alone is often insufficient to reveal underlying gait disorders present during normal, everyday activities. We use a dual-task paradigm, walking while simultaneously performing a second cognitive task, to assess the effects of divided attention on motor performance and gait control. Objective quantification of such clinically relevant gait changes is necessary to deterPublished online: October 27, 2010 Dr. Stephanie A. Bridenbaugh Basel Mobility Center, Acute Geriatrics University Hospital Basel Schanzenstrasse 55, CH–4031 Basel (Switzerland) Tel. +41 61 328 6882, Fax +41 61 265 3883, E-Mail bridenbaughs @ uhbs.ch © 2010 S. Karger AG, Basel 0304–324X/10/0000–0000$26.00/0 Accessible online at: www.karger.com/ger Bridenbaugh/Kressig Gerontology 2 When gait is no longer completely automatic, other tasks performed while walking can lead to gait disturbances and even falls. Dual-task paradigms of gait analysis for cognitive stress resistance testing and for examining the association between divided attention and motor control are discussed. Detection of such gait disorders allows the timely introduction of individually tailored interventions targeted at improving gait regularity, automaticity and thus also gait safety. Examples of such evidence-based intervention programs are introduced. Gait in Healthy Seniors In order to appreciate detrimental gait changes that may lead to falls, it is beneficial to be familiar with some of the gait changes that accompany normal, healthy aging. David Winter was one of the first to compare gait parameters of healthy older (mean age: 68 years) and young (mean age: 25 years) adults [6] . His study showed that the cadence was the same in both groups. Yet, compared to the young adults, the older adults had significantly reduced gait speed, decreased stride length and increased double support time ( fig. 1 ). The toe push-off was less vigorous. Horizontal heel contact velocity was also significantly higher. Menz et al. [7] later reported a reduced gait speed, decreased step length and increased step timing variability in older healthy adults (mean age: 79 years) compared to young adults (mean age: 29 years). These changes represent either a degeneration of the balance control system or compensatory adaptations providing safer gait. Gait, Falls and Fall Prediction in Seniors Falling is classified as one of several geriatric syndromes. Defining features of geriatric syndromes includes the contribution of multiple risk factors and the Step length Stride length (gait cycle) Stride width Left toe-off Left toe-off Right toe-off Right single support Right stance phase 0% 15% 45% 60% 100% 0% 40% 55% 85% 100% Right swing phase