Bicycle helmet vibrations and relation to helmet dislodgement during normal road use.

Bicycle safety helmets suffer accelerations up to 30 m /s2 under normal riding conditions. During shocks accelerations of 100 m /s can be encountered. In assessing the forces involved on the helmet, the worst case would consider the head in a forward horizontal position with gravitational acceleration aiding vibrational acceleration. More test should be done to extend the research.