Effects of external helmet accessories on biomechanical measures of head injury risk: An ATD study using the HYBRIDIII headform

Abstract Competitive cycling is a popular activity in North America for which injuries to the head account for the majority of hospitalizations and fatalities. In cycling, use of helmet accessories (e.g. cameras) has become widespread. As a consequence, standards organizations and the popular media are discussing the role these accessories could play in altering helmet efficacy and head injury risk. We conducted impacts to a helmeted anthropomorphic headform, with and without camera accessories, at speeds of 4 m/s and 6 m/s, and measured head accelerations, forces on the head-form skull, and used the Simulated Injury Monitor to estimate brain tissue strain. The presence of the camera reduced peak linear head acceleration (51% – 4 m/s impacts, 61% – 6 m/s, p