The effect of facial protection, impact location, and neckform stiffness on peak linear acceleration, risk of injury, and energy loading measures of horizontal impacts on a hockey helmet

Abstract

Helmets were originally designed and implemented to protect players from skull fractures and traumatic brain injuries by minimizing linear impact accelerations. The sport of hockey, however, has evolved, and now includes faster, larger, and stronger players. As a result, mild traumatic brain injuries or concussions have become more associated with the sport. Some solutions have been proposed to minimize concussions on hockey players by attaching facial shielding to helmets and increasing the neck strength of players, but these solutions have not been extensively explored in the research. Based on these concerns, the first purpose of this study was to assess the durability of a hockey helmet when exposed to multiple impact testing protocols. The second purpose was to investigate the influence of facial shielding and helmet location on the stiffness of a hockey helmet. The third purpose was to examine the influence of impact location, type of facial protection, and neck stiffness on peak linear acceleration, severity index, and the energy loading properties of hockey helmets during dynamic horizontal impacts. For the first purpose of the study, the analysis revealed that attenuation properties of the helmet were not compromised at either location after 200 impacts were administered. This aided in the determination of a threshold impact count to replace the helmet during dynamic testing. For the second purpose, the analysis revealed that adding facial shielding to a hockey helmet increases its stiffness properties. Additionally, this analysis revealed that the stiffness of the helmet varies according to helmet location. For the third purpose, the analyses revealed statistically significant three-way interactions between facial shielding, impact location, and neckform stiffness on measures of peak linear acceleration, (see document). Two-way interactions at each level of neckform stiffness were examined for each of the three dependent variables to help explain the three-way interactions and the results of the analysis revealed statistically significant two way interactions and subsequent simple main effects for impact location and facial shielding. The findings of this work add to previous literature concerning helmeted headform impact testing by examining the role that facial shielding plays in combination with neck strength and impact location in brain injury prevention for the sport of hockey. Finally, the outcome of this study adds to the current understanding of injury mechanisms in the sport of hockey, and have practical applications for helmet designs and manufacturers, standards organizations, coaches and hockey players.