Age Differences in a Combined Walking and Grasping Task

Previous studies have identified patterns of coordinated control when adults combine gait and grasping. What remains unclear is whether the coordination of these two tasks differs between adolescent and adult groups. Groups of adults and adolescents were asked to walk across an instrumented gait mat in three conditions: walk forward, walk and grasp a small target, and walk and grasp a large target. Spatiotemporal measures of gait/gait variability and grasp/grasp variability were quantified. Both adolescents and young adults exhibited decreased velocity, decreased step-extremity ratio, and increased percent of gait cycle spent in double support when grasping compared to walking alone. The major influence of grasping was seen during the final step before grasp in both groups. Change scores between walk forward and walk and grasp conditions were larger for adolescents. Furthermore, spatiotemporal measures of gait and grasping were more variable in adolescents. These results suggest that superimposing grasp onto gait is more challenging for adolescents than young adults. The challenges associated with combining these two tasks is particularly evident in the last step prior to object contact and suggests that the increased planning and execution demands required to perform these coordinated skills affects adolescents to a greater extent than young adults.