Effect of Mild and Moderate Exertion on the Sideline Assessment of Concussion: A Randomized Controlled Trial.

Objective: Identify the effect size of mild and moderate levels of exertion on common sideline concussion assessment tool scores in healthy adolescent athletes.

Design: Three arm randomized controlled trial.

Setting: High school training rooms.

Participants: Forty-seven healthy adolescents who participate in school sports and have not had a concussion within the past month.

Interventions: Participants performed the Sport Concussion Assessment Tool 5 (SCAT5) and Vestibular Ocular Motor Screen (VOMS) at rest. Participants were randomized to perform No Exertion (n = 16, 15-minute seated rest), Mild Exertion [n = 16, 50%-55% of heart rate (HR) max for 15 minutes on a treadmill], or Moderate Exertion (n = 15, 70%-75% of HR max). Participants then repeated the SCAT5 and VOMS immediately after a 2-minute cool down.

Main outcome measures: Effect size of change after exertion.

Results: Few differences were seen after mild and moderate levels of exertion. In the combined sample, there was a small increase in the number of modified balance error scoring system errors [d = -0.17 (-0.52, 0.19)], a medium degree of improvement in symptoms [d = 0.38 (0.01, 0.74)], and a small degree of improvement in cognitive scores [d = 0.20 (-0.16, 0.55)] after exercise. No differences on VOMS testing were observed.

Conclusions: The SCAT5 and VOMS seem to be consistent measures even after mild and moderate levels of exertion (HR <75% of age-appropriate maximum). A future study should aim to identify the effect of maximal exertion.