The effect of a concurrent task on the walking performance of preschool children.

Forty-eight children, aged 4-6 years, walked while performing or not performing an easy or difficult concurrent motor task (carrying a tray with or without marbles on it) or cognitive task (repeating a series of digits forwards or backwards). The temporal-distance gait parameters were measured using a GAITRite electronic walkway system. Dual-task costs were calculated as the difference between the children's walking performances with and without the concurrent task. Overall, walking alone was easier than walking while performing a concurrent task. A greater dual-task cost was observed when the concurrent task was difficult compared to when it was easy. However, this effect of difficulty was found for the motor task only. The results suggest that walking demands both the central processing capacity and the domain- and modality-specific processing resources in normal 4-6-year-old children.