Comments on Depreitere et al. Lateral head impacts and protection of the temporal area by bicycle safety helmets. J. Trauma. 2007;62:1440.

The side of the head is vulnerable to trauma in bicycle injuries. Depreitere et al., demonstrated contact between a flat-faced pendulum, and the side of cadaver heads, when bicycle helmets was worn. Computer design methods were used to interpret these experiments, showing that typical helmets safely absorbed 75% of the impact kinetic energy before pendulum-to-head contact occurred. Furthermore, in typical oblique impacts with the road, two factors improve the head protection. The tangential velocity component slightly improves the helmet performance, whereas prior shoulder impact on the road decreases the head impact velocity. It is concluded that current helmets provide adequate protection for typical lateral head impacts.