The effects of impact management materials in ice hockey helmets on head injury criteria

The objective of this study was to compare the capacity of vinyl nitrile and expanded polypropylene, two materials commonly used in ice hockey helmets, to reduce the peak linear acceleration, peak angular acceleration, and head injury criterion values during a direct impact to a hybrid III headform. Six different ice hockey helmets were tested using a pneumatic linear impactor at velocities similar to those in hockey. The results showed that helmets using expanded polypropylene foam liners are significantly better at reducing linear acceleration; however, helmets using vinyl nitrile foam liners are significantly better at reducing angular acceleration. Furthermore, the impact location influenced the performance of the liner.