Influence of single and dual tasks on gait stability and gait speed in the elderly

Background : Gait stability during dual tasks is important for elderly persons, especially for elderly individuals in need of care. A study was conducted to assess gait stability by using Lyapunov exponents (λS) during single task and dual task conditions in independently living elderly people (Go-Goes) and elderly people in need of care (No-Goes). Material and methods : This study was conducted with 26 participants (average age 82 ± 9.4 years) who were allocated to the Go-Goes or No-Goes group. Outcomes were mediolateral and vertical Lyapunov exponents (λS) from accelerometer data and gait speed under single task and dual task conditions. Results : In both groups significantly higher mediolateral and vertical Lyapunov exponent values as well as significantly lower walking speeds under dual task conditions were found in both groups. The effect sizes were small to moderate for mediolateral λS and large for vertical λS and these differences remained when the analyses were adjusted for walking speed. Conclusion : Elderly people showed lower gait stability and gait speed under dual task conditions compared to single task conditions