Role of Helmet Fit on Angular and Linear Accelerations of Head in Ice Hockey

Abstract

Increasing the protection efficiency of helmets is counted as the biggest challenge in ice hockey. The main objective of this study is twofold: first to understand the effect of fitting on the protection capability of ice hockey helmets, and second to determine a possible optimal fit with respect to minimum head accelerations. A purpose-built monorail drop tower was utilized to perform front and front boss impacts at a velocity of 4.47m/s on a custom headform outfitted with a commercial helmet (CCM Resistance) with no gap (tight fit), 2mm (regular fit), and 5 mm gaps (loose fit). It was observed that while in both impacts linear accelerations were lower for the regular fit model, the loose fit model predicted the lowest angular accelerations. A loosely-fitted helmet provides non-deterministic shifting upon impact which generally leads to a wider standard deviation of linear and angular accelerations. The results indicated that in front impacts while introducing a gap reduced the risk of focal injuries, only the loose fit model suggested lower risks of concussive injuries. However, the regular and loose fit models showed better protection against focal and concussive injuries in the front boss impacts, respectively.