Effects of manual task complexity on gait parameters in school-aged children and adults

•We examine the interference effects of simple and complex manual tasks on gait.•Simple manual tasks do not disrupt gait in adults or school-aged children.•Complex manual tasks have greater costs on gait in school-aged children than adults.

This study examined the dual-task interference effects of complexity (simple vs. complex), type of task (carrying a pitcher vs. tray), and age (young adults vs. 7-10 year old children) on temporal-spatial and variability measures of gait. All participants first walked on the GAITRite® walkway without any concurrent task, followed by four dual-task gait conditions. The group of children had a more variable step length and step time than adults across all walking conditions. They also slowed down, took fewer, smaller steps and spent more time in double limb support than adults in the complex dual task conditions. Gait in healthy young adults and school aged children was relatively unaffected by concurrent performance of simple versions of the manual tasks. Our overall analysis suggests that dual-task gait in school aged children is still developing and has not yet reached adult capacity. This study also highlights the critical role of task demand and complexity in dual-task interference.