Bike Helmets: What You Need to Know

Dr. Alexis Halpern on why wearing a helmet is a must — every time you ride.

People cycling through city street with and without bike helmets
People cycling through city street with and without bike helmets

Need a reason to wear a bike helmet? Consider these stats. In the New York metro area alone, 17 bicyclists have been struck and killed by cars and trucks so far this year, seven more than in all of 2018.

Across the nation, over 1,000 bicyclists died in accidents involving motor vehicles and by other means in 2017, and almost 330,000 were injured, according to the Centers for Disease Control and Prevention. What’s more, according to a 2015 study published in JAMA (the Journal of the American Medical Association), the percentage of injured cyclists who suffered head injuries increased from 10 to 16% from 1998 to 2013, and torso injuries increased from 14 to 17%.

The good news: Many of these injuries could be lessened or avoided with proper helmet use. According to research by the National Institutes of Health, helmet use reduces the chances of a head injury by 48%, serious head injury by 60%, traumatic brain injury by 53%, face injury by 23%, and the total number of killed or seriously injured cyclists by 34%.

Health Matters spoke with Dr. Alexis Halpern, an assistant attending physician at NewYork-Presbyterian/Weill Cornell Medical Center and an assistant professor of clinical medicine at Weill Cornell Medicine, about the importance of wearing a helmet and how to tell if your helmet fits properly.

What types of bike injuries are the most prevalent?
In general, abrasions, lacerations, bruises, and broken bones are probably the most common. There are a lot of upper extremity injuries like breaking your wrist or separating your shoulder. People also get lower extremity injuries, including leg or foot injuries … but even in a minor fall, you’re very likely to get a bruise or a scratch or cut. And then there’s the head trauma that happens.

Why is it important to wear a helmet?
Because you can’t ever be sure that nothing will happen. There are a lot of people who say, “I’m a good rider. I’ll be fine.” It doesn’t matter. It’s not always up to you. Other people aren’t always paying attention. You may need to swerve to avoid people or turn to avoid a car and then lose your balance and fall over. Those are the times when you’re likely to hit your head.

You don’t even have to be going fast. If you fall and hit your head even slightly, you can fracture your skull, you can suffer a traumatic brain injury, you can even sometimes get bleeding in your head or in your brain.

If you fall and hit your head, the helmet could be the thing that saves your life.

Infographic that says "Need a good reason to wear a bike helmet?" and provides statistics on injuries and fatalities.

Accident Analysis & Prevention (August 2018)

How does the helmet work?
The outside of the helmet is hard and the inside is soft. So, if your head hits the ground, the hard part of the helmet takes the impact, and disperses it over a larger area than if your head just hit the ground. Your head is cushioned by the soft part of the helmet. So all that impact that the helmet absorbs, your head would be getting without the helmet.

What should one look for when choosing a helmet?
Buy a helmet at a bike store. Go in and work with someone who knows what they’re talking about so that you can find the best helmet for you. Make sure that it comes down over your forehead, and that you can tighten it so that it’s not moving around. You want to make sure that it’s comfortable on your head, that it doesn’t give you a headache. You also want to make sure that there’s enough aeration so that your head doesn’t get too hot. If it isn’t comfortable, you’re not going to wear it. So get one that’s comfortable.

Portrait of Dr. Alexis Halpern

Dr. Alexis Halpern

How often should you replace your helmet?
Anytime you have a fall or hit your head, especially if it cracks or there’s any significant trauma to the helmet, you should replace it. Once it is damaged, it is not going to function the same way or absorb the same way. If there are no incidents, there’s a general rule about replacing your helmet every 10 years since the material might start to wear down.

What other advice do you have for bicyclists?
Avoid distractions, avoid alcohol or any other intoxication before you get on your bike — or while you’re on your bicycle. When you’re making a left turn, remember that cars aren’t necessarily looking for bikes there, or they won’t necessarily think to stop for a bike. Wear reflective, light-colored clothing, especially if you’re going be out and it’s going to become dark. Put reflectors on your bike; have a headlight, have a flashing red light, so that cars know you’re there, especially when it gets dark. And use hand signals. When you make a left, put your left arm out sideways and use your index finger to point left. If you’re making a right, extend your left arm out but bend it upward at the elbow at a 90-degree angle. People put on their blinkers, so why wouldn’t you use your hand signals on a bicycle? You’re still a vehicle in traffic; you have to think of yourself that way.

Dr. Alexis Halpern is an assistant attending physician at NewYork-Presbyterian/Weill Cornell Medical Center and an assistant professor of clinical medicine at Weill Cornell Medicine.

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