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

Experimental setup.

Anteroposterior (Fx) ground reaction force dependent variables of a trial for a young subject, where the cutaneous stimulus was presented at every trial and before toe-off. The vertical arrows represent time of stimulus and reaction time (RT). Vertical lines represent movement onset, swing toe-off, swing heel-strike, and stance toe-off. Dependent measures of the stance and swing limb ground reaction forces are indicated. In this trial, reaction time was 360ms and peak shear force (Fx) of the stance limb was 57% of BW.

Reaction time for baseline and dual-task conditions. The dual-task stimulus was presented at every trial and random trial both before and after toe-off. Abbreviations: EA, every trial after toe-off; EB, every trial before toe-off; RA, random trials after toe-off; RB, random trials before toe-off.

Toe clearance for the baseline and dual-task conditions. The dual-task stimulus was presented at every trial and random trial both before and after toe-off. Abbreviations: see fig 3.