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Should Bike Helmets Be Equipped With Airbags?

Scientists say a self-inflating, Swedish helmet could prevent brain injuries.


Cycling sends more than 500,000 Americans to the emergency room each year, with roughly 85,000 reporting head injuries in 2009. Hard knocks on the noggin are especially dangerous as they can cause skull fractures, concussions, and other brain traumas. Could science find a way to protect cyclists from such life-threatening injuries?

That’s a question Stanford researchers recently took to the lab. Minimizing brain injuries would be a simple matter of bulking up padding and protection in helmets—having people pedal around in motorcycle helmets would be a great way of minimizing trauma. But cyclists overwhelmingly prefer today’s plastic-covered, polystyrene-foam helmets due to their light weight, ventilation, and appearance, and that’s not the best thing for the brain.

“Studies have shown that although wearing the [foam] helmet decreases the risk of severe head injury by approximately 75 percent, the reduction in mild traumatic brain injury (mTBI) rates is statistically insignificant,” the researchers write in the Annals of Biomedical Engineering.

But there is a new kind of “helmet” that’s light, inconspicuous, and plump with padding—the Swedish Hövding device, which wraps like a sash around the neck and explodes into a fat air-pillow on event of a crash. The Stanford crew performed drop tests with anthropomorphic dummies and two types of helmets, the standard foam and the airbag-equipped Hövding. The results: The airbag helmet cut the risk of concussion 8 times below that of the popular foam version.

Head-injury criterion values were lower for airbag-equipped helmets (the four left and middle bars) than foam helmets. Red bars represent blows to the top of the head, blue bars to the side. (Kurt, Laksari, et al./Annals of Biomedical Engineering)

There are some qualifications, one being the deterrent factor of the Hövding’s $330 price tag and another the air pressure inside the helmet’s inflatable sac. Here’s more from Neuroscience News:

In the testing, the air bag helmet was pre-inflated and the researchers maximized the pressure of the air inside the helmet before each drop in order to get these results.

“As our paper suggests, although air bag helmets have the potential to reduce the acceleration levels that you experience during a bicycle accident, it also suggests that the initial pressure that your air bag helmet has is very critical in reducing these acceleration levels,” [Mehmet] Kurt said.

Without the maximum amount of air, the air bag helmet could bottom out, causing the head to hit the ground with much more force than if it were wearing a traditional foam helmet. In current versions of the air bag helmet, a chemical process triggers expansion, which doesn’t seem to guarantee maximum air pressure.

An airbag-equipped helmet used in Stanford’s drop tests. (Kurt, Laksari, et al./Annals of Biomedical Engineering)

About the Author

  • John Metcalfe
    John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.