“You only get one brain.” This is what Meeryo Choe, MD, FAAN, says to her young patients who complain that bike helmets are too hot, too bulky, or too uncomfortable.

It may seem unnecessary to remind people that they’ll be using the same brain for their entire lives, but it’s an effective way to emphasize the dangerous reality of traumatic brain injuries and their long-term effects. Doctors can’t bandage an injured frontal cortex or prescribe a medication to repair a damaged cerebrum, so the best way to treat a brain injury is to prevent it from happening in the first place. 

“I’ll often say that you can transplant many organs, but you can’t get a brain transplant,” says Dr. Choe, a child neurologist at the University of California Los Angeles BrainSPORT Program. “It’s important that we make sure our kids learn from a very young age that the way to protect your brain and limit your risks when you participate in fun activities is wearing the right equipment.”

Bike Helmet Safety for Children

Bike riding is one of the leading causes of head injuries in children. Although not every injury is serious, many are: In 2020, University of Pittsburgh researchers reviewed 10 years of data from bike-related deaths of people under 18 years old and found that 75% of deaths were related to head injuries. The study also concluded that 85% of those injuries could have been prevented if the child had been wearing a properly fitted bike helmet.

Data show that states requiring riders to wear a bike helmet report fewer bicycle-related head injuries and deaths. Yet surveys also show that many people still do not wear a bike helmet.

Additionally, electric bikes are leading to an increase in severe head injuries. “Due to the greater speed and weight of electric bikes, it is essential to have more robust helmets. More speed and weight lead to a greater amount of energy transfer (and related damage) to the head and brain,” says Thomas Watanabe, MD, clinical director of the Drucker Brain Injury Center at Jefferson Moss Rehabilitation.

Most electric bikes can go as fast as 30 miles per hour (mph), though some can reach 50 mph. By comparison, pedal bikes typically go between 8 and 16 mph for beginner or intermediate riders. Because of this, a traditional bike helmet should not be used for electric bike riding, but an electric bike helmet is suitable for pedal bike riding. Electric bike helmets “provide more protection to the temples and back of the head and the overall construction provides greater strength,” Dr. Watanabe says.

Helmets are Important for Everyone, but Especially Children

Brain injuries “are bad for all of our brains…and injuries to developing brains could create greater and more long-lasting problems than injuries to a fully developed brain,” says Dr. Watanabe.

The human brain is generally fully developed by age 30. The prefrontal cortex, which is responsible for functions including impulse control and emotional regulation, is the last part of the brain to reach full maturity.

Children should start wearing helmets as soon as they begin riding on a bike, either pedaling on their own or riding as a passenger in an extra seat or cart. Children under one year old should not be transported on a bike.

“Very young children have very weak necks, and if their necks can’t support a helmet, they shouldn’t be on any sort of bike or anything that puts them at risk of falling and hitting their heads,” Dr. Watanabe says.

How to Tell if a Bike Helmet Fits Correctly

A helmet should be Consumer Product Safety Commission (CPSC) certified and clearly labeled on the helmet packaging.

Helmets should be worn snugly over the forehead, and the straps should be tight under the chin. “The risk is [the helmet] could get knocked sideways and not be [protecting] the right part of your head when you are in a crash,” says Lara McKenzie, PhD, principal investigator in the Center for Injury Research and Policy at Nationwide Children’s Hospital. “If it’s too loose, it could also slip over your eyes.”

Dr. Watanabe suggests using the 2-V-1 rule: 

• The front of the helmet should be two horizontal fingers away from the eyebrows. 
• The straps should make a V shape around the earlobe.
• There should be a one-finger gap between the chin and the strap.

Consider your child’s head shape. Some heads are more oval-shaped, and some are rounder. Helmets are available in multiple fits. “If you open your mouth fully, you should feel the helmet tugs just a little bit; it’s giving a little pushback,” Dr. Watanabe says.

How to Encourage Children to Wear Their Helmets

Guardians should tell children who don’t want to wear a helmet that no helmet means no bike riding.

“People seem to be very comfortable saying, ‘Wear your seatbelt in the car or the car won’t go,’” Dr. McKenzie says. “Parents have to enforce that rule with their children: If you’re not going to wear [a helmet], you can’t go out riding.”

One way to encourage helmet use is by starting early—Dr. Choe’s son was a preschooler when he started wearing a helmet while using his balance bike. “That becomes his expectation,” she says. “He knows every time that he's going to go on a [bike], he has to wear a helmet.”

It can be helpful to store the bike and helmet together so that time isn’t spent looking for the helmet when they are ready to ride their bike. “We develop habits, as kids, even as adults, the habit becomes: First thing I do when I get on my bike is grab my helmet,” Dr. Watanabe says. 

Another way to encourage kids to wear a helmet is by doing it yourself. Researchers in Saudi Arabia found that children who saw their parents wearing helmets were more likely to wear one too. And children who grew up wearing helmets were more likely to continue the practice into adulthood.

“It's important to role model it….Often parents will say, ‘Okay, you have to wear a helmet, and I don't,’ and that doesn't make any sense to the kid,” Dr. Choe says. “My husband and I are always wearing helmets when we go for bike rides, even if we're just cruising around our neighborhood.”

Make the helmet fun, even fashionable. Kids are more likely to wear a helmet if it has a fun design, their favorite color, or favorite cartoon character. Adult helmets, too, can be aesthetically appealing. Some companies make adult helmets that resemble straw hats.

A helmet only protects you if you actually wear it. Dr. McKenzie says she has to stop herself from shouting at riders with their helmets tied to their handlebars. “I can’t tell you the number of kids who do that,” she says. “I’m thinking, ‘What are you doing? You left the house with the helmet. Just put it on your head.’”

Bike riding is a great form of exercise. However, protecting your child’s head is crucial. Wearing a properly fitted helmet reduces the risk of head injury, helping children stay safe while they are having fun.

What About Bike Rentals?

Many cities have bike or scooter rentals to get around town. Riding a rented bike without a helmet puts you at risk of serious injuries from a fall or crash. “It remains important to [wear] a helmet when you rent a bike or scooter,” Dr. Watanabe says. “Many bike rental shops do offer helmets to rent.” The best option? Be prepared. If you know you will be renting a bike before leaving the house, bring your helmet with you.

Additional Resources

Dr. Choe recommends helmets that are approved by the National Operating Committee on Standards for Athletic Equipment (NOCSAE)—a nonprofit that sets safety guidelines for athletes.

Because electric bikes move much faster, they require enhanced helmets. Dr. Watanabe suggests looking for electric bike helmets with an NTA 8776 certification—a Dutch standard. 

Visit the Virginia Tech bicycle helmet ratings website to compare helmets’ safety ratings and costs.