Neurological complications associated with sports‐related brain trauma have been a recent concern and focus of research. In turn, sensor technologies have been developed to count head impacts during sports. Low‐level impacts present a low risk for concussion but are implicated in long‐term neurological conditions. The effectiveness of helmets at managing angular acceleration at this energy level is unknown. The objective of this research was to examine the ability of American football, lacrosse and hockey helmets and the bare head to manage angular accelerations for low‐level impacts (20g). A 50th percentile Hybrid III headform was impacted using a pendulum system at nine centric and non‐centric impact sites. Linear and angular accelerations were recorded using nine single‐axis accelerometers arranged in a 3‐2‐2‐2 array. A consistent trend across centric and non‐centric impact sites was observed for peak angular acceleration: football helmets produced the lowest levels, followed by the bare headform, with the lacrosse and hockey helmets producing the highest values. At the crown site, however, the football helmet produced the highest angular acceleration. Peak angular acceleration at low impact energies was influenced by the type of helmet and impact condition. While there is little risk in terms of linear acceleration for low‐level impacts, angular accelerations approach a 25% risk of concussion. Helmets must be tested and designed to manage these impacts.
Keywords:
Head impact count, Hybrid III headform, Pendulum impact system, Sub‐concussive impact