Validation of impact-absorbing football helmet facemask for head injury prevention with simulation

American football reports the highest rate of head injury in the United States. While football helmets have been developed to protect players and reduced severe head injuries, concussion incidents have not declined in the National Football League. A facemask is one of the helmet components mounted on the front opening of the helmet to protect the face, and it is the second most impacted location causing concussions. It is made of carbon steel or titanium and has high rigidity, which is effective at protecting the face from direct contact injury, but it is ineffective at absorbing impact. This study aimed to assess whether a facemask contributes to head injury prevention against front impact. We hypothesized that if a facemask absorbs impact, it would drop the concussion risk. We conducted a ram impact test and a helmet-to-helmet collision test to validate a facemask using numerical simulation. For the front ram impact test simulation, highly ductile polycarbonate plastic was applied to the facemask to cushion the impact. Various polycarbonate facemask designs reduced the head acceleration from the impact by more than 46% versus the titanium facemask. For severe helmet-to-helmet collision simulation with an angled front impact, a hybrid facemask composed of polycarbonate frame and steel wire decreased translational and rotational acceleration of the struck head and dropped concussion risk by approximately 50%. This study indicated that a facemask played a significant role in lowering concussion risk if it was designed to absorb impact.