Dual-task effect on gait balance control in adolescents with concussion.

Objective: To prospectively and longitudinally examine how concussion affects gait balance control in adolescents during single- and dual-task walking.

Design: Cohort, prospective, repeated-measures design.

Setting: Motion analysis laboratory.

Participants: Adolescents (N=20) identified as suffering a concussion were matched with healthy control subjects (N=20) and tested 5 times across a 2-month period after injury.

Interventions: Not applicable.

Main Outcome Measures: Gait temporal-distance parameters included average walking speed, step length, and step width; whole body center of mass (COM) parameters included medial/lateral displacement and peak COM medial/lateral and anterior velocities; dual-task cost, which was defined as percent change from single- to dual-task conditions; and Stroop test accuracy.

Results: No between-group differences were observed for step length and step width. The dual-task cost for average walking speed for subjects with concussion was greater than control subjects across the 2-month testing period (main effect of group P=.019), as was the dual-task costs for peak anterior COM velocity (main effect of group P=.017) and total COM medial/lateral displacement (main effect of group P=.013). The total COM medial/lateral displacement (group × task interaction P=.006) and peak COM medial/lateral velocity (main effect of group P=.027; main effect of task P=.01) were significantly greater in subjects with concussion compared with control subjects during dual-task walking. Subjects with concussion were significantly less accurate than controls on the Stroop test (main effect of group P=.004).

Conclusions: The findings suggest that concussion affects the ability of adolescents to control body posture during gait up to 2 months after injury. Furthermore, dual-task paradigms may provide additional useful information in the clinical assessment and recovery of concussion.