The Influence of a Cognitive Task on Stair Descent by Younger Adults

Abstract

[Purpose] The aim of this study was to examine the center of pressure (COP) trajectory variables and response time when young adults descended stairs while simultaneously performing a concurrent secondary Stroop task that required direct attention. [Subjects and Methods] Twenty healthy young adults (10 males and 10 females) participated in the study. Each subject first completed a Stroop task while standing (baseline). Next, they stood in a predetermined position at the top of a custom-built 3-step staircase and negotiated the stairs at a self-paced speed with and without performance of a concurrent secondary Stroop task. Subjects were asked to place only one foot on each step (foot-over-foot). The response times to the secondary task and the COP trajectory with and without performance of the concurrent secondary Stroop task were measured. [Results] The Stroop task response time while descending stairs was significantly longer than the Stroop task response time during static standing. The mediolateral and anteroposterior displacements of COP and the length of COP path, as well as the average velocity of the COP, were significantly greater when subjects performed the secondary task than without the secondary task. [Conclusion] The study suggests that subjects' ability to descend stairs is lessened with the addition of the concurrent secondary attention-demanding task, and that the addition of divided attention tasks places an apparently higher demand on balance control that may prove to be challenging for subjects at high risk of falling.