A study of seven Seattle area hospital emergency departments and two county medical examiner’s offices shed light on bicycle injuries and
Risk of serious injury was increased by collision with a motor vehicle, cyclists who self-reported speeds of greater than 15 mph, those under 6 years of age, and cyclists over the age of 39 years, as compared with adults 20-39. Risk for serious injury was not affected by helmet use.
-Source: Injury Prevention, January 2015