Impact energy attentuation of protective football headgear against a yielding surface.

There is no standard test to assess the ability of soft headgear to prevent the likelihood of head injuries in the Australian football codes. Therefore the impact energy attenuation of protective football headgear was assessed using a yielding artificial headform and impact surface to characterise the impact scenario. Seven soft football headgear of varying mass, materials and thickness were dropped from a height to generate impact energy of 56 J. The headgear were tested for a number of different impact locations. Accelerometers within the headform monitored the impact mechanics. A Head Injury Criterion (HIC) of 1000 was selected as the injury threshold. Reliability data, collected one week apart, revealed that the results were highly reproducible. Although several of the headgear generated HIC values about 1000 for the various impact locations, only one of the headgear, that with the greatest thickness (15 mm) generated a HIC score below 1000 for impacts to the side and front of the headgear. There was a significant correlation between headgear thickness and HIC scores. It was concluded that all but one of the commercially available soft football headgear tested provided inadequate impact energy attenuation due to the limited amount of padding. It is postulated that the padding material of the headgear would need to be at least 15 mm thick to offer adequate protection.