Likelihood of Brain Injury in Motorcycle Accidents: A Comparison of Novelty and DOT-Approved Helmets

During a motorcycle accident, a rider’s helmet may dissipate energy to reduce the likelihood of serious brain injury. Novelty helmets lack the energy-absorbing layer between the comfort liner and the outer shell of the helmet. In this study, we compared the injury mitigation capabilities and associated brain injury potential of novelty helmets to three US DOT-approved motorcycle helmets. The analysis was performed using a drop tower system. Helmeted Hybrid-III and magnesium head-forms were dropped onto a slab of asphalt with contact to the upper, back region of the helmets. The first drop height was chosen to simulate a fall from the typical seated height of a rider on a cruising style bike, and the second height was chosen to yield an impact speed that conformed to the DOT testing requirements, 6 meters per second (13.4 mph). Resultant accelerations, head injury criterion (HIC), and probability of an AIS 4+ brain injury were calculated for each drop test. For both drop heights tested, resultant accelerations and HIC scores for the novelty helmet were approximately four times larger than those calculated for the DOT-approved full-face helmet. Data revealed that in impacts representative of falling from a typical seated height onto asphalt, wearing a DOT-approved helmet could reduce the risk of AIS 4+ brain injuries from over 90% to less than 3%.