Graded treadmill running protocol on dynamic visual acuity and balance for athletes with and without recent concussion history

Abstract

Athletes interpret dynamic visual scenes quickly and accurately during physical exertion. It is important to understand how increased exertion may impact vision and cognition following sport-related concussion (SRC). Purpose: To examine the effect of treadmill exercise on dynamic visual acuity (DVA) for athletes with and without SRC. Methods:Varsity athletes following recent SRC (CONC=12) were compared to athletes without SRC (ATHLETE=19). The DVA task presented a Tumbling ‘E’ target in four possible orientations during random walk (RW) or horizontal (H) motion at a speed of 30°/s. Participants performed DVA trials standing on a force plate (1000Hz) at four time points: 1) pre-exercise (PRE-EX), 2) immediately (POST1), 3) 10-minutes (POST10), and 4) 20-minutes post- exercise (POST20). Performance was calculated as a change in DVA score from PRE-EX and median response time (RT, ms). Balance control was analyzed using the root mean square of centre of pressure displacement (dCOP). Results: Both groups maintained DVA scores for both motion types with similar balance strategies post-exercise. CONC responded more slowly by POST10 and POST20 during RW-motion compared to ATHLETE. Conclusion: Both groups elicited similar exercise-induced benefits on DVA following exercise. However, a portion of athletes with SRC may experience transient cognitive benefits following exercise.