Role Of Age, Gender, And Bmi In Test-retest Performance On Dynamic Exertion Testing For Concussion

Abstract

Aerobic and dynamic exertion testing is used to inform return to play decisions following sport-related concussion (SRC). However, there are limited data on the repeatability of these tests and we know little about the role of demographic and health status factors on outcomes. PURPOSE: To evaluate test-retest reliability of a new dynamic exertion test (EXiT) protocol including age-estimated heart rate (HR) and rating of perceived exertion (RPE) following aerobic (AERO) and dynamic (DYN) movement components, agility task completion time, and total symptoms; in relation to age, gender, and body mass index (BMI). METHODS: A total of 79 (34-F [43%], 19.63 ± 5.01 yrs) healthy athletes completed the following EXiT components across 2 visits (8.72 ± 4.65 days): 12 min treadmill run (AERO) and DYN; dynamic circuit (CIRC), ball toss (BT), box-drill shuffle (SHUF) and carioca (CAR), zig-zag (ZZ), pro agility (PA), and arrow agility (AA) tasks. Participants were categorized into 14-19yo (YOUTH) or 20-31yo (ADULT); male (M) or F; and low or high (50th%) BMI. Two-way, mixed, intra-class correlation coefficients (ICC) were used to evaluate test-retest reliability. Paired samples t-tests were used for HR and test completion time, with Wilcoxon tests used for symptoms and RPE. RESULTS: Results supported a reduction in HR following the CIRC (p < .05), and moderate to high agreement following AERO (ICC = .579-.910, p < .01) and DYN (ICC = .503-.618, p < .05). A reduction in completion time was reported for YOUTH on SHUF (p = .004) and ADULT on SHUF, CAR, and ZZ (p < .05). Both M and F experienced a reduction in SHUF, CAR, and ZZ (p < .05); and a reduction among high BMI for SHUF, CAR, ZZ, and AA tasks (p < .05). Results supported moderate to high agreement for completion time on SHUF (ICC = .607-.935), CAR (ICC = .564-.950), ZZ (ICC = .750-.949), PA (ICC = .546-.940), and AA (ICC = .793-.820); as well as RPE (ICC = .707-847) and symptoms(ICC = .517-.919) (p < .05). CONCLUSIONS: The findings indicate that the EXiT outcomes are consistent across repeated administrations in healthy athletes, regardless of age, gender or BMI. As such, changes in performance across time are more likely to reflect effects of concussion and the recovery process than performance inconsistency and these potential confounding factors.