Effect of a cognitive task and light finger touch on standing balance in healthy adults.

The purpose of the study was to investigate the individual and combined effects of applying light finger touch and performing a cognitive task on postural sway. Fourteen healthy young individuals stood on the force platform with light finger touch contact applied to an external stable structure and without finger touch. Both tasks were performed with and without a cognitive task (counting backward from a randomly chosen three-digit number). The center of pressure excursion and velocity as well as sway area were calculated. Participants demonstrated significantly smaller postural sway in the presence of a finger touch contact (p < 0.05), while postural sway was increased during the performance of the cognitive task (p < 0.05). When two tasks were performed simultaneously, body sway increased as compared to standing with light touch only (p < 0.05) and decreased when compared to standing and performing the cognitive task only (p < 0.05). This suggests that a positive effect of finger touch on body sway could be diminished by the simultaneous performance of a cognitive task. The outcome provides a foundation for future studies of the individual and combined effects of light finger touch and cognitive tasks on postural control.