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Wednesday, March 18, 2009
Motorcycle Helmets - How They Save Your Life
Currently twenty states have universal helmet laws requiring everyone who rides to wear a helmet. Three states have no laws and the remaining twenty six states have some sort of modified law. In 2000 Florida changed its universal law to require everyone under the age of 21 to wear a helmet but left wearing a helmet as an option for anyone over 21 who has at least $10,000 in health insurance. Florida currently accounts for 9% of all motorcycle fatalities nationwide and, according to the Insurance Institute for Highway Safety (IIHS), in the years after the law went into effect, motorcycle deaths in Florida increased by 25%.
The National Highway Safety Administration (NHTSA) estimates that helmets reduce the fatality rate for motorcyclists by 37%. Their studies also show that un-helmeted riders are three times more likely to suffer traumatic brain injuries compared to helmeted riders. The Center for Disease Control says that the average costs to treat traumatic brain injury run about $150,000 in the first year of a multi-year treatment plan. Much of the cost for medical treatment, rehabilitation, and disability payments become a taxpayers challenge. That is one of the primary reasons why state governments feel they have the right to pass and enforce helmet laws.
To fully understand this issue, it's important to understand what happens in a motorcycle crash and how the helmet works.
Every crash obeys the laws of physics. Newton's first law of motion states that an object in motion tends to remain in motion, meaning that, once the motorcycle's travel comes to an abrupt halt, the rider will continue to travel at the same speed he was going before the bike stopped until something else acts to stop his travel; usually the concrete roadway. Newton's law also states that Mass X Velocity = Force. That means that a rider weighing 160 pounds won't hit the concrete with a force of 160 pounds but with a much greater force. By using an on-line force calculator, we can compute that a 160 pound man flying off the bike at 25 mph and coming to a stop within 5 feet, will strike the concrete with a force of 669 pounds. Once the rider's head hits the concrete, his brain, cushioned only by a very thin layer of cerebrospinal fluid, will also follow Newton's law until it presses up against the skull. There is no way to break the laws of physics but you can take steps to lessen their force with the use of a motorcycle helmet.
A good helmet can act to absorb and distribute the force of the impact, and thus, lessen the impact on the rider’s head. It does that in two ways. First the fiberglass shell of the helmet takes the full brunt of the force and dampens it by cracking and distributing the force around the outside of the helmet; this is similar to the way a car's body is designed to crush in order to protect the car's interior. Second, a good foam lining provides a cushion, somewhat like a car's airbag, to slow the speed of the head before impact. Without a helmet, the skull itself cracks and, with the forces involved, the tiny bit of fluid surrounding the brain is not adequate to cushion the brain. Multiple studies show that the brain injury rate and the number of fatalities are greatly reduced when a rider wears a helmet. Studies also show that the weight or rigidity of a helmet has little impact on neck and spinal cord injuries.
To help you select a good helmet, there are a lot of web sites for motorcycle enthusiasts with articles on the pros and cons of various helmets and advice on how to select the best one for you. Visit TestQuestionsandAnswers.com for more information on motorcycle safety and a motorcycle practice test.