Concussions in Ice Hockey : Accident Reconstructions Using Finite Element Simulations

Sammanfattning: Ice hockey, one of the most popular sports in the world, is a contact sport that is always associated with huge risks of traumatic brain injuries (TBIs) resulting from high-velocity impacts. Although technology in player protection equipment has advanced over the years, mild traumatic brain injuries (mTBIs) like concussion remain prevalent. Finite Element (FE) analysis presents a methodology to recreate accidents in an effort to study the effects of protective helmets and predict brain injuries. This study aimed at improving the response of an existing ice hockey helmet FE model during different impact conditions and reconstructing an ice hockey collision using FE simulations. First, the shear response of the Expanded Polypropylene (EPP) material for the helmet liner was improved by means of a single element simulation to replicate the experiments. Simulations of helmet drop tests were then performed to validate the helmet FE model. Two different designs of the helmet model were implemented, one with normal properties of the foam and the other with a softer foam. Actual cases of ice hockey accidents were then reconstructed using positioning and impact velocities as input from video analysis. As player to player collisions had not been reconstructed for ice hockey using two player models, it was decided to use two full body Human Body Models (HBMs) for the reconstruction. The biomechanical injury parameters for the accident reconstruction were plotted and compared with injury thresholds for concussion. The kinematic results achieved from the drop test simulations showed a considerable decrease in peak values for resultant accelerations, resultant rotational accelerations, and resultant rotational velocities. These results also exhibited better CORrelation and Analysis (CORA) scores than previously achieved. The biomechanical analysis of the accident reconstruction showed the strains in the brain for the concussed player to be more than the threshold for concussion, which confirms the validity of the reconstruction approach. The results of this study show an improved response of the helmet FE model under different impact conditions. They also present a methodology for ice hockey accident reconstruction using two full body HBMs.