The Effect of a Dual-Task on the Center of Pressure Trajectory of Healthy Young Adults during Obstacle Crossing

Abstract

Abstract.[Purpose] The purpose of this study was to examine the center of pressure (COP) trajectory and response time when young adults initiate gait and step over an obstacle while simultaneously performing a secondary Stroop task.[Subjects] Twenty healthy young adults (ten males and ten females) participated in the study.[Methods] The subjects first completed a Stroop task while standing (baseline) and then initiated gait and stepped over an obstacle at a self-paced speed with and without a secondary Stroop task. The response times to the secondary task and the COP trajectory were measured.[Results] The Stroop task response time in the stepping condition was the longest, followed by the times for initiating gait and standing conditions (p<0.01). There were main effects for both the Stroop task and stepping conditions for the mediolateral (M-L) displacement of the COP and the length of the COP path for both feet (p<0.01, respectively). However, there were no significant differences among the tasks for the anteroposterior (A-P) displacement of the COP for both feet. [Conclusion] This study suggests that divided attention degrades the obstacle avoidance abilities of healthy young adults and the apparently greater demand of postural control may prove as difficult for populations that are at risk of falling.

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

“…The finding of increased COP displacement in the M-L direction and length of the COP path is similar to a previous report that the M-L displacement of COP and the length of the COP path were increased in subjects performing gait initiation or obstacle crossing with a concurrent secondary task 42) . In the current study, subjects appeared to have less postural control, which was manifest as an increase in the amplitude of the displacements of COP in the M-L and A-P directions when performing the stair descent with the concurrent secondary Stroop task.…”

“…Another study observed that older women had slower verbal reaction times than younger women and longer reaction times in a sitting position than in a standing position 41) . Kim 42) also demonstrated that the response time for obstacle crossing when a secondary Stroop task was provided was significantly longer than the response time in static standing only.…”

The influence of accuracy constraints on EMG and kinetic variables during gait initiation

“…Significant correlations between kinetic events, time to stepping-limb TO, amplitude and duration of TA, and intended velocity of GI have been reported 5 ) . Similar patterns of modulation seem to occur when stepping to a new height 15 ) or over an obstacle 7 , 16 , 17 , 18 , 19 , 20 , 21 ) .…”