Head impacts in non-helmeted sports: Measuring and locating the impact force

Abstract

Mild traumatic brain injury within contact sports is a growing concern due to the serious risk of injury and concussion. Extensive research is being conducted looking into head kinematics during impacts in non-helmeted contact sports utilizing instrumented mouthguards, allowing researchers to record accelerations and velocities of the head during and after an impact. This does not, however, allow the location of the impact on the head, and its magnitude and orientation, to be determined. This research proposes and validates an algorithm using rigid body dynamics that approximates the impact force and determines its location and orientation from instrumented mouthguard kinematic data. Impact data captured from an experimental laboratory test using an instrumented mouthguard and five finite element simulations are used to validate the algorithm. The obtained results from both validation methods highlight the effectiveness of the proposed impact magnitude and location algorithm as impact locations were calculated within 12 mm of the impact center for all conducted tests. Additionally, components of force unit vectors (direction cosines) obtained from the algorithm were within ±0.03, which equates to less than 11% of the components of applied force unit vectors, highlighting the accuracy of impact direction vector established from the algorithm. This algorithm has the potential to significantly aid researchers conducting field tests within non-helmeted sports by reducing the time required to analyze and determine head impact locations.