Linear impactor tests were conducted on football helmets from the 1970s–1980s to complement recently reported tests on 1990s and 2010s helmets. Helmets were placed on the Hybrid III head with an array of accelerometers to determine translational and rotational acceleration. Impacts were at four sites on the helmet shell at 3.6–11.2 m/s. The four generations of helmets show a continuous improvement in response from bare head impacts in terms of Head Injury Criterion (HIC), peak head acceleration and peak rotational acceleration. Helmets of 2010s weigh 1.95 ± 0.2 kg and are 2.7 times heavier than 1970s designs. They are also 4.3 cm longer, 7.6 cm higher, and 4.9 cm wider. The extra size and weight allow the use of energy absorbing padding that lowers forces in helmet impacts. For frontal impacts at 7.4 m/s, the four best performing 2010s helmets have HIC of 148 ± 23 compared to 179 ± 42 for the 1990s baseline, 231 ± 27 for the 1980s, 253 ± 22 for the 1970s helmets, and 354 ± 3 for the bare head. The additional size and padding of the best 2010s helmets provide superior attenuation of impact forces in normal play and in conditions associated with concussion than helmets of the 1970s–1990s.
Keywords: Protective headgear; Recreation and sport; Concussion; Helmets; Sport equipment