THE UTILITY OF A MULTIDIRECTIONAL SUBMAXIMAL EXERTIONAL STEP AS PART OF AN EXERTIONAL REHABILITATION PROTOCOL AFTER CONCUSSION

BACKGROUND: This study aimed to identify whether a 5 Step Exertional Rehabilitation Protocol including a submaximal multi-directional stage (Step 5) has clinical utility for functional activity and sport clearance. Exertional Rehabilitation (EP) is a graded protocol of aerobic exercise ranging from light linear exertion (Step 1) to submaximal linear exertion (Step 4)(1,2). In our 5 Step Protocol, Step 4 is followed by standardized multi-directional functional movements at high intensity intervals (Step 5) to rule out ongoing exertional intolerance. HYPOTHESIS/PURPOSE: We aim to investigate if Step 5 testing demonstrates statistical evidence for its use in determining concussion recovery timelines and its diagnostic usefulness. METHODS: This retrospective-chart review analyzed 60 Step 5 EP test attempts in post-concussion patients, ages 21 or younger, between Jun2019-Jun2020. Tolerance was determined by a concussion specialist who evaluated for the onset of signs/symptoms by surveying the patient throughout exercise and autonomic assessment with cardiac monitoring and pre/post orthostatic testing. Pre/Post exertion King-Devic (K-D) and vestibular testing on Force Plate were completed following Balance Error Scoring System positions. A positive change in K-D was defined as a ≥2 second delay in score on two of three reading cards from the pre-exertion testing. A positive change in vestibular testing was defined as a ≥0.2deg/sec change in the composite balance score from the pre-exertion testing. RESULTS: The total number of failed Step 5 attempts was 21.7%. Of the failed attempts, 38.5% demonstrated dysautonomia, 92.35% had symptoms, and 30.8% demonstrated both dysautonomia and symptoms. Force Plate balance scores significantly worsened in failed attempts 15.4% of the time while passed attempts only 2.1% of the time. K-D scores did not show a statistically significant difference although failed attempts did have slightly worsened scores. CONCLUSION: Formal Step 5 testing is a useful diagnostic tool for understanding recovery stage, activity tolerance, and sport clearance. Autonomic, visual, and vestibular testing can be useful as objective markers of test tolerance. TABLES/FIGURES: CITATIONS: 1) Leddy JJ, Haider MN, Ellis MJ, Mannix R, Darling SR, Freitas MS, Suffoletto HN, Leiter J, Cordingley DM, Willer B. Early Subthreshold Aerobic Exercise for Sport-Related Concussion: A Randomized Clinical Trial. JAMA Pediatr. 2019 Apr 1;173(4):319-325. 2) Gagnon etal. Another look at active rehabilitation for slow-to-recover sport-related concussion in children and adolescents: further evidence to support its effectiveness. BJSM, 2013.