A bicycle helmet helps in protecting the head of a cyclist from injuries caused by falls and impacts.
Unlike a motorcycle helmet that encloses the whole head, a bike helmet is lightweight and well ventilated. Riding a bicycle is an aerobic activity which increases body temperature significantly. The head should be properly cooled down and temperature regulated since complications such as fainting spells and dizziness may occur.
Despite the obvious protection that a bike helmet can offer, there are still ongoing debates on whether bike helmet use should be mandatory or optional. Those that are against mandatory helmet use state that riding a bicycle is intrinsically safe and what makes the activity dangerous are the public roads and highways.
One of the most criticized report is the study released by Robert S. Thompson, M.D., Frederick P. Rivara, M.D., M.P.H., and Diane C. Thompson, M.S. in the New England Journal of Medicine in 1989. "A Case-Control Study of the Effectiveness of Bicycle Safety Helmets" or "TRT 89" as it is sometimes called is said to be the most quoted study with regards to bicycle helmets and was crucial to the passage of helmet legislation across the world.
Critics of the report raised issues such as bias among the authors towards helmet use and data manipulation to come up with more favorable results leaning towards a pro-helmet stance. Data such as the often criticized and also cited 85%/88% statistic came solely from this report. It has been quoted and repeated in other reports while some question the validity of the statement.
The 85%/88% states that the use of a bicycle helmet reduces head injuries by 85% and brain injuries by 88%.
Just recently, Olympic Gold medal winner Bradley Wiggins called for legislation making it compulsory for cyclists to wear helmets in the UK. This was announced after a cyclist died in a crash near Olympic Park in London. It is unsure whether or not the cyclist was wearing a helmet.
Children's bicycle helmets shown to be effective in impact and crush tests
A favorite physical activity engaged in by Americans is bicycling, and children are perhaps its most ardent participants; it has been estimated that 70% of children ages 5 to 14 ride bicycles. Bicycling is not without its dangers, however, and one of the worst is the risk of head and brain injury during a crash. According to the US Centers for Disease Control, head injury is the most common cause of death and serious disability from bicycle crashes. The best protection offered to mitigate this injury is the bicycle helmet. However, few cyclists wear helmets regularly, and children are less inclined to wear helmets than adults: national estimates of helmet use among children range from only 15% to 25%. To determine just how effective bike helmets can be, neurosurgeon Tobias Mattei and his research team at the Illinois Neurological Institute and Bradley University tested how well helmets withstood forces of impact and crush tests when covering human cadaver skulls. They found that wearing a helmet can substantially reduce (by up to 87%) the acceleration experienced by the skull during an impact and can aid the skull in resisting forces up to 470 pounds in a crush accident. Full details on the results can be found in "Performance analysis of the protective effects of bicycle helmets during impact and crush tests in pediatric skull models. Laboratory investigation," by Mattei and colleagues, published today online, ahead of print, in the Journal of Neurosurgery: Pediatrics.