Determinants of Head Impact Exposure in Youth Football

Principal Investigator: Thayne A. Munce, PhD, Manager, Exercise Physiology, Sanford Sports Science Institute

Institution: Sanford Research

Title: Determinants of Head Impact Exposure in Youth Football

Abstract: Recent concern over brain injuries in football has extended from professional athletes to players of all ages. With approximately 70% of all football players in the US being younger than high school age and youth players having an extended window of injury exposure, there is a strong public health rationale to better understand the risk of brain injury in this population. Numerous efforts to make youth football safer are underway, but limited actionable data have made it difficult to develop these tactics in an evidence-based manner. Furthermore, although recent studies have filled significant gaps in the scientific literature regarding head impact exposure (i.e., injury risk) in youth football, important questions about the determinants of impact events, which are influenced by both intrinsic and extrinsic elements of play, remain to be explored.

Aims: Examine the relation between head impact exposure and 1) intrinsic and 2) extrinsic characteristics of play in youth football.

Study Design: Head impact exposure of twenty-five middle school football players will be measured at every practice and game throughout one season. Each session will also be videotaped and subsequently analyzed to quantify intrinsic and extrinsic characteristics of play that are associated with discrete collision events and cumulative head impact exposure.

Materials and Methods: Players will be instrumented with Head Impact Telemetry (HIT) System (Riddell Corp., Elyria, Ohio) helmet-mounted accelerometer units for assessment of head impact exposure. All sessions will be videotaped and subsequently analyzed using pre-determined criteria to quantify specific characteristics of play. Both intrinsic and extrinsic factors will be evaluated and compared to head impact exposure measures.

Main Outcome Measures: Head impact exposure measures obtained from the HIT System will include linear acceleration, rotational acceleration, impact location and impact frequency. These measures will be evaluated for their association with intrinsic (player position, pre-collision distance, blocking/tacking role, etc) and extrinsic (practice/game, play type, drill type, game/practice situation, etc) characteristics identified from video analysis.

Significance: Overall, this study will provide novel data that can rapidly advance efforts to improve the health and safety of youth football players. A better understanding of the relation between specific elements of play and head impact exposure in youth football will provide insights about game/practice activities and characteristics of play that are associated with high magnitude and/or high frequency head impacts. This valuable, but currently unavailable, information can guide the development of evidence-based player contact rules, policies and instructional programs. Furthermore, these data can be incorporated into more advanced protocols for testing football helmets that take into account specific, on-field properties that influence head impact exposure in youth players; thus, assisting in the creation of youth football helmet safety standards.