Objective: To begin to understand changes in locomotor navigation in elite athletes following concussion.
Methods: Clinical measures and gait analysis were undertaken on average 37.33 days (SD = 4.8) postconcussion for 6 athletes as well as for a control group of athletes matched for age, sex, and team. The locomotor task consisted of walking at a self-selected speed along an unobstructed or obstructed path with and without a visual interference task. The trends for 4 dependent variables were described (2 for gait behavior and 2 for cognitive behavior). A principal component analysis was used to reduce data to root sources of variance among these variables. General group differences were tested with Wilcoxon matched-pairs tests on factorial scores.
Results: Athletes with concussion were symptom free at the time of testing and their neuropsychological test results were not different from those of athletes in the control group. However, when the laboratory data between paired groups were compared, descriptive analyses suggested potential group differences in navigating the obstacle. The simultaneous Stroop task appeared to present difficulty for both groups. A significant group effect was found on the component of the factorial analysis that was highly loaded with both gait and cognitive variables (minimum clearance, Stroop task errors, and cognitive dual-task costs), generally supporting the descriptive analyses by suggesting that athletes with concussion do not navigate the targeted complex environments like the control group.
Conclusions: Athletes with concussion appear to still show navigational deficits in environments well after being considered fully recovered according to current return-to-play protocols. Although still preliminary and requiring further study, the present findings suggest that functional assessment within complex environment contexts could be considered before sending athletes back to play following a concussion, even in the absence of postconcussion symptoms or with normal clinical outcomes.
Université Laval (Drs Fait and McFadyen), Quebec Rehabilitation Institute (Dr Cantin), and Centre for Interdisciplinary Research in Rehabilitation and Social Integration (Drs Fait, Leblond, and McFadyen), Quebec City, and Université de Montréal, Montreal (Dr Swaine), Quebec, Canada.
Corresponding Author: Bradford J. McFadyen, PhD, Centre for Interdisciplinary Research in Rehabilitation and Social Integration (IRDPQ), 525 Boul Hamel, Quebec G1M 2S8, Canada (firstname.lastname@example.org).
The authors thank Guy St-Vincent for his technical assistance, Eric Huard and Janick Bisson for their consultation and development of the Stroop presentation program, and the TBI unit of the IRDPQ. This study was partially funded by the Canadian Institutes of Health Research and the Natural Sciences and Engineering Research Council of Canada (to Dr McFadyen) and partial Ontario Neurotrauma Foundation-Quebec Rehabilitation Network stipend (to Dr Fait).
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The authors declare no conflicts of interest.