The Effect of a Dual-Task on Obstacle Crossing in Healthy Elderly and Young Adults

Abstract

Kim H-D, Brunt D. The effect of a dual-task on obstacle crossing in healthy elderly and young adults. Objective To investigate the effect of a dual-task on step initiation over an obstacle. Design Repeated-measures design between groups. Setting University laboratory. Participants Ten healthy, community-dwelling elderly adults and 10 healthy young adults. Interventions Not applicable. Main Outcome Measures The effect of a reaction time task on ground reaction forces, toe clearance, and temporal events in stepping over an obstacle. Results Ground reaction forces of the swing limb before toe-off did not differ between the groups and was not affected by task difficulty. Stepping with a random stimulus after toe-off was the most difficult task, whereas stepping with a predictable stimulus before toe-off was the easiest task. Reaction time and stepping time were greater and toe clearance was less for the elderly subjects. Both groups had a decrease in toe clearance and an increase in reaction time and stepping time as the task became more difficult. Conclusions Our findings indicate that even healthy older adults may be at risk for falls in situations where they are engaged in concurrent tasks. The data support the inclusion of dual-task activities in fall prevention programs.