Date of Award

Spring 2021

Document Type


Degree Name

Master of Science (MS)


Athletic Training – Post Professional Concentration

Committee Chairperson

Katherine Morrison, Ph.D, LAT, ATC

Committee Member

Pamela Chlad, M.Ed., RN, LAT, ATC

Committee Member

Dan Baer, Ph.D, LAT, ATC


Context: Recent evidence suggests that accumulating head impact exposures may have an effect on neurocognitive function over time. Objective: The purpose of this study was to examine the relationship between HIEs and reaction time (RT) over time. Design: Observational cohort study. Setting: Data collection occurred at a Division III college throughout the 2018 and 2019 competitive football seasons. Participants: Six football players volunteered for this study. Main Outcome Measures: HIEs (95%, 99%, and HIElin threshold categories) using helmet accelerometers and ImPACT reaction time (ImP) measurements (baseline (BL), post-season 1 (PS1), post-season 2 (PS2)). Results: A total of 1,411(235.17±237.97) HIEs were sustained by participants in the 2018 season, and increased to 2,118 (353±381.19) in the 2019 season. Dependent t-tests revealed that composite RT significantly improved at the PS2 measurement (0.60±0.08ms) when compared to BL (0.68±0.11ms), (P=.048). Conclusion: Noticeable trends in accumulating HIEs were present within the subject group. Sub-concussive impacts had a greater presence compared to concussive impacts throughout the study period. Changes in reaction time measurements occurred over time, however further research is needed to validate the impact of repetitive HIEs on long-term RT measurements in collision sport athletes. This study contributes to the ongoing research of HIE trends in Division III collegiate football.