Head Impact Kinematics and Brain Deformation in Paired Opposing Youth Football Players

Abstract

Head impact exposure is often quantified using peak resultant kinematics. While kinematics describes the inertial response of the brain to impact, they do not fully capture the dynamic brain response. Strain, a measure of the tissue-level response of the brain, may be a better predictor of injury. In this study, kinematic and strain metrics were compared to contact characteristics in youth football. Players on 2 opposing teams were instrumented with head impact sensors to record impact kinematics. Video was collected to identify contact scenarios involving opposing instrumented players (ie, paired contact scenarios) and code contact characteristics (eg, player role, impact location). A previously validated, high-resolution brain finite element model, the atlas-based brain model, was used to simulate head impacts and calculate strain metrics. Fifty-two paired contact scenarios (n = 105 impacts) were evaluated. Lighter players tended to have greater biomechanical metrics compared to heavier players. Impacts to the top of the helmet were associated with lower strain metrics. Overall, strain was better correlated with rotational kinematics, suggesting these metrics may be better predictors of the tissue-level brain response than linear kinematics. Understanding the effect of contact characteristics on brain strain will inform future efforts to improve sport safety.

The Impact of Drop Test Conditions on Brain Strain Location and Severity: A Novel Approach Using a Deep Learning Model

“…Similarly, a study completed using kinematic data from head impact youth football players found that impacts to the top of the helmet were associated with lower strain metrics [40]. Impacts to the side of the helmet were associated with the highest peak rotational velocity and strain metrics [40]. These results corroborate with a study that compared the brain response of frontal and lateral impacts using FE modelling, with predicted shear stress in the brain being much higher in lateral impacts [41].…”

“…Results from the Simulated Injury Monitor (SIMon) and Global Human Body Model Consortium (GHBMC) models suggested that frontal impacts to the crown and forehead resulted in the lowest brain strain values [39]. Similarly, a study completed using kinematic data from head impact youth football players found that impacts to the top of the helmet were associated with lower strain metrics [40]. Impacts to the side of the helmet were associated with the highest peak rotational velocity and strain metrics [40].…”

The Effect of Virtual Reality Training on Heading Skills in 12-13 Years Old Child Footballers

“…Recent studies in football show that traumas caused by heading have increased. In particular, concussions constitute 9.6% of injuries in all young American football players (Milef et al, 2022). In football, the definition of concussions has changed over time.…”

“…A statistic that has been reasonably stable over time has found that any head or neck injury (crush, tear, concussion, eye, etc.) accounts for 15% of all injuries (Kirkendall & Sayers, 2020;Milef et al, 2022;Patton et al, 2021). However, clinical and research studies have focused on concussions, which are very rare injuries.…”

“…There were 3 documented concussions in 64 games at the 2014 FIFA Brazil World Cup at a rate of 0.14/1,000 match hours. In other words, the injury frequency per match is 0.05 (Kirkendall & Sayers, 2020;Milef et al, 2022;Patton et al, 2021;Tomblin et al, 2020). Based on these cases, virtual reality training may be used in child football players to improve their heading skills without a ball being impacted on the head (Wood et al, 2021).…”