OBJECTIVE: To determine if individuals with a concussion demonstrate altered cognitive performance while standing still or while walking relative to uninjured controls.
DESIGN: Cross-sectional. SETTING: Sports-medicine clinic. PARTICIPANTS: Youth and collegiate athletes diagnosed with a concussion, assessed within 10 days of injury, and a group of uninjured control subjects. INDEPENDENT VARIABLES: Concussion and control groups. MAIN OUTCOME MEASURES: Participants stood still for 30 seconds while completing a cognitive task (spelling words backward, serial subtraction, or reverse month recitation) and completed a similar set of cognitive tasks while walking. Our primary outcome variables were (1) overall cognitive task performance (accuracy) and (2) the total number of task items completed during testing (completion rate) during standing and walking conditions.
RESULTS: One hundred ninety-one participants completed the study: 94 with concussion (tested mean = 5.1 ± 2.9 days postconcussion; 51% female; mean age = 17.1 ± 3.3 years) and 97 control subjects (40% female; mean age = 17.5 ± 2.1 years). The concussion group completed significantly fewer responses than the control group while standing still (37.3 ± 14.5 vs 45.1 ± 17.6 responses; P = 0.03) and while walking (22.7 ± 7.5 vs 33.6 ± 13.4 responses; P < 0.001). They were also significantly less accurate at spelling words backward (81.2 ± 28.6% correct vs 89.8 ± 15.0% correct; P = 0.049) and reciting months in reverse order (95.8 ± 10.4% correct vs 98.2 ± 4.2% correct; P = 0.034) while walking.
CONCLUSIONS: Athletes displayed lower cognitive task accuracy rates after concussion compared with control subjects during backward spelling and reverse month recitation tasks while walking but similar levels of accuracy while standing. Assessment of cognitive performance during dynamic tasks may be a clinically viable method to evaluate post-concussion deficits.