Anatomy of a Motorcycle Helmet And How It Protects Your Brain
How A Motorcycle Helmet Works to Protect Your Brain
If you’re a rider, you should take some basic precautions like carrying the correct motorcycle insurance, keeping your bikes in top mechanical condition and wearing the proper safety equipment and riding gear.
Most US states require all riders to wear helmets, with a few notable exceptions.
Before you buy a new, or your first, motorcycle helmet, understanding how a helmet works to protect your brain and possibly save your life is important information to have on hand.
Helmets are constructed of several layers of protection designed to prevent head, brain and neck injuries:
- The outer shell – Generally made from fiber-reinforced polycarbonate or other thermoplastic composite materials, the outer shell of a motorcycle helmet is designed to collapse and even crack on impact in order to absorb shocks delivered by impact.
- The Liner – Usually constructed of polystyrene and designed to compress and absorb impact, this is the business end of a well-made helmet.
- The Padding – Included for comfort, soft foam provides comfortable fit and can often be detached cleaning.
- The Face Shield – provides protection against wind-driven road debris and any bugs you may encounter. If you’ve ever had a Junebug strike your face at speed, you surely know how important a face shield can be to moderate impacts.
- The Chin Strap –is pretty obviously designed to keep your helmet on your head. Straps come in a variety of designs and those designs vary widely in the amount of comfort they provide. A chin strap which proves uncomfortable while you’re trying it on at the dealer’s will sure be annoying on a long ride, so pay particular attention to your choices here.
- The Ventilation System – keeps fresh air flowing through the helmet for cooling purposes, and a properly ventilated helmet will prevent the face shield from fogging or building up condensation, so again, this is a critical factor to consider when choosing a helmet.
During 2008, statistics show that almost 60% of bikers killed in crashes weren’t wearing helmets, and that should be a sobering number is you ride without one.
Since 1980, all adult-sized helmets designated for use on the highway in the United States must meet DOT standards. Helmet dealers and distributors must ensure that all these types of helmets they sell display the DOT sticker, and if they don’t have this sticker, assume that they are so-called novelty helmets and not assured of delivering you the proper protection from impacts.
Snell has conducted motorcycle helmet testing since the 1950s, and use of these Snell standards is voluntary but common among manufacturers. Unlike the DOT standards, Snell testing is regularly updated as helmet designs and technologies improve.
While the test methodologies differ, the goal is the same, to ensure that approved helmets have the maximum life-saving and shock-absorbing capability.
We’ve covered how helmets are made, now you need to know how they protect your brain and the mechanism of head injuries.
You might think the helmet’s purpose is to prevent a rider’s head from splitting open, and while that is one function, it’s not the only one. A helmet can, and often does, split and still provide it’s most essential function – slowing the violence of an impact to the brain tissues. Skull fractures are not always life threatening. It gets dicey when a fracture causes a depression of the skull which impinges on the brain underneath. Skull fractures which don’t impinge on the brain heal relatively quickly.
Injuries to the brain however, frequently result in death, permanent disability or diminished brain function like personality changes. The actual tissues of the brain are very limited in their capacity to recover after a traumatic injury, so a motorcycle helmet’s primary function is to dissipate trauma to the brain tissue.
Closed head injury, meaning a trauma in which the skull is not broken, is the most common type of injury resulting from a motorcycle accident. Like the trauma which occurs when a boxer takes a shot to the head from an opponent, it’s the violent acceleration (and deceleration) of the head which causes the brain to slosh around inside the skull. It’s that sloshing motion which does the most critical damage to brain tissue.
An impact to the front of the head causes the brain to lurch forward inside the skull. This motion causes compaction of the tissue near the site of the impact while simultaneously stretching the tissue on the side of the head opposite the impact. Once the impact has occurred, an opposing force reverses the process and the brain rebounds inside the skull, stretching the tissue near the impact site and squeezing the tissue on the opposite side. When this sequence of events happens, blood vessels attached to the brain may also break and cause internal bleeding.
An ideally-constructed helmet liner is stiff enough to decelerate the head as smoothly and uniformly as possible before it is completely crushed.
For a more complete rundown of particular helmet brands, check out this article from Motorcycle Cruiser magazine as they test and compare seven flip-face motorcycle helmets.
Without the proper riding gear, bad things can happen to you, and your insurance needs can get complicated. We’re here to help on all counts…