Detecting and Ameliorating the Effects of Routine Sport-related Head Impacts on Brain Health

Abstract

Participation in contact sports has been under scrutiny as former contact sport athletes have been found at increased risk of adverse brain health, raising concern about the safety of routine head impacts in contact sports. Studying the acute effects of such impacts has proved difficult due to the subtleness of the brain’s response to subconcussive impacts. The aim of this thesis was to investigate variables, that may be sensitive to the effects of subconcussive impacts in order to find ways to mitigate head impact burden. The first chapter provides background information about the effects of repetitive subconcussive head impacts (RSHI) on brain health and outlines the aims of the thesis. Chapters 2 and 3 examine the use of biofluid markers for detecting the effects of RSHI by investigating already existing research. Chapter 2 (Lember et al., 2024) is the first scoping review dedicated to examining biofluid marker levels following RSHI exposure. The chapters conclude that although some markers demonstrate sensitivity to the effects of RSHI, the findings are generally mixed and the use of biofluid markers in this setting is currently premature. As such, Chapter 4 assesses whether reducing the number of head impacts and the use of headgear ameliorates functional brain response to subconcussive impacts using cognitive, vestibular and electrophysiological measures that have previously shown sensitivity to the effects of RSHI. The study found no heading related changes in any of the outcome measures, suggesting that the measures were either not sensitive, or no brain changes occurred in response to the impacts. Chapter 5 examines whether the use of headgear and (neck) strength can attenuate impact accelerations, finding that headgear nor strength affected heading induced head accelerations. The final chapter explores the methodological difficulties of studying the effects of RSHI with suggestions and considerations for future research.