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Senseless: An In-Depth Look at the State of Bicycling Helmet Technology

Bicycle Helmet

Story at-a-glance -

  • Bicycle helmets are designed to prevent skull fractures in catastrophic accidents, but they do little to prevent concussions and other serious brain injuries
  • Bicycle helmets sold in the US are required to meet minimum standards set by CPSC, including withstanding a six-foot drop test at room temperature as well as in extreme conditions
  • The required CPSC benchmark is based only on linear acceleration – the force of your skull hitting the pavement. It does not take into account rotational acceleration, which is linked to severity of concussions
  • Newer technology called MIPS (Multi-Directional Impact Protection System) and AIM (Angular Impact Mitigation) may help to reduce the risk of concussions from bicycle accidents, but the technology is still emerging
  • Since 1998, more than 90 percent of the people who died in bicycle accidents weren’t wearing helmets

By Dr. Mercola

Well, the last vestiges of the polar vortex are disappearing and many may be ready to start cycling. Unfortunately, only about half of cyclists regularly wear helmets. This is tragic as helmets can save your life or prevent serious injury.

I've always been a big fan of helmets. When I was in medical school in 1980, I accidentally sailed off a three-foot concrete ramp at 16 mph and my helmet saved a serious head injury and I only broke my collarbone. Believe me, bike helmets 35 years ago did not look anywhere as cool as they do today.

Fortunately, more people are wearing helmets today, and this might be saving lives… from 2008 to 2010, an average of 655 bicycle-traffic deaths occurred, compared to 804 from 1995 to 1997. This suggests that helmets are working to protect people in cycling accidents, and this may be the case for major crashes, especially when it comes to reducing skull fractures.

However, a fascinating investigation published in Bicycling Magazine highlights major problems in bicycle helmet industry, including antiquated safety standards, testing that does not at all mimic real-life crashes and helmet innovation based more on ventilation and comfort than on actual safety during a fall.

According to the review, while bicycle helmets may help in catastrophic accidents, they do little to prevent concussions and other serious brain injuries to which avid cyclists are especially vulnerable.

Bike-Related Concussions Are on the Rise

As helmet wearing has increased, so have brain injuries among cyclists. From 1997 to 2011, bike-related concussions increased 67 percent in the US, according to data from the U.S. Consumer Product Safety Commission (CPSC).

This might seem puzzling until you take a look at the development of bicycle helmets -- and the safety standards to which they're still mostly built to meet. When helmets were first being designed and tested, the consequences of concussions were not widely understood.

Today, we know that a concussion, which is caused by a blow to your head, can lead to headache and problems with concentration, memory, judgment, balance, and more. The effects are usually temporary, although now, it's known that long-term complications may occur.

Among them, your risk of epilepsy doubles in the first five years following a concussion, and if a second concussion occurs before you've healed from the first, it can lead to rapid and fatal brain swelling.1

Research has also shown that people who experience multiple concussions over their lifetime, such as professional athletes, are at an increased risk of cognitive impairment including chronic traumatic encephalopathy (CTE), a form of brain damage that's similar to Alzheimer's disease.2

Clearly, if you're wearing a bicycle helmet, you want it to protect your brain from a concussion as well as skull fracture, but to date, such technology doesn't really exist. As reported by Bicycling Magazine:3

"…helmets were developed only to protect against massive head trauma, like cracking open your skull, and simply haven't been designed to prevent less immediately catastrophic injuries like concussions. What's more, none of us—not you, not me, not the helmet manufacturers or even the testing agencies—know for certain whether your helmet will prevent you from getting hurt."

Most Bike Helmets Are Made to Meet Outdated Safety Standards

Bicycle helmets sold in the US are required to meet minimum standards set by CPSC (which took effect in 1999 and hasn't been changed since). This standard requires bicycle helmets to withstand a six-foot drop test at room temperature as well as in extreme conditions.

The problem is that this benchmark is based only on linear acceleration – the force of your skull hitting the pavement. Modern helmets work to slow this blow by distributing it across a larger surface area.

They also typically contain an impact-absorbing liner made of expanded polystyrene (EPS), although, unless the impact is strong enough to cause the EPS to disintegrate, it's actual ability to absorb much impact is questionable.

Here again, we have an instance where the current design of most bicycle helmets works for catastrophic impacts… but much less so for falls that might give you a concussion (without cracking open your skull).

Linear acceleration is only one type of impact in a bicycle accident. Another is rotational acceleration, in which your brain rotates on impact, leading to "shear strain" even if your skull isn't visibly damaged.

It is damage caused by rotational acceleration that is linked to the severity of concussions, but there are no standards requiring bicycle helmets to protect against it. Bicycling Magazine explained:4

"Imagine a plate of fruit gelatin being jarred so hard that little cuts open throughout the jiggly mass. That strain [from rotational acceleration] can damage the axons that carry information between neurons.

There are other factors involved, but research has consistently pointed to rotational acceleration as the biggest single factor in a concussion's severity. The CPSC helmet benchmark is based solely on linear acceleration. There's never been a standards test, required or voluntary, for rotational acceleration."

There are other safety certifications for bike helmets, including from the American Society for Testing and Materials (ASTM), which has made small revisions in recent years, including revising testing standards to account for different weight heads. They are also considering a shorter drop test that might help improve helmets in less severe impacts. However, ASTM's standard is completely voluntary.

MIPS: The Latest Technology in Bicycle Helmets

Most bicycle helmet improvements in recent decades have focused on making helmets lighter, better ventilated and more comfortable to wear. It wasn't until 2008 that Swedish neurosurgeon Hans Von Holst, along with mechanical engineer Peter Halldin, developed a new technology called MIPS (Multi-Directional Impact ­Protection System). MIPS offered something that previous helmets did not: a possibility of reducing concussions. As reported in Bicycling Magazine:5

"Halldin [and] Von Holst noted that the head has a built-in protection ­system of sorts—a low-friction layer of cerebrospinal fluid between the brain and the skull. The fluid allows the brain to move a bit; it acts as an energy-absorbing system. Von Holst and Halldin hatched an idea: What if they mimicked that action within a helmet?

That wasn't their only insight. Since the 1950s the drop test has been based on a straight 90-degree impact. But… studies have shown that most bike falls result in an impact angle between 30 and 45 degrees. The Swedish team invented a test rig that examined drops at those more realistic angles.

By 2008, after years of sketching, testing, and prototyping, they had a working ­model. Their MIPS (Multi-Directional Impact ­Protection System) helmet contained a ­low-friction slip plate between the head and EPS liner. On impact, the helmet rotates independent of the MIPS liner, absorbing some rotational acceleration."

In 2012, Swedish company POC released the first MIPS system in a bike helmet geared toward mountain biking, in order to reduce concussion risk. Last year, US brand Scott also introduced MIPS technology to a bike helmet.

An even newer emerging technology is AIM (Angular Impact Mitigation), which uses a honeycomb liner in place of EPS. The liner floats slightly within the helmet, allowing it to shift upon impact to help absorb rotational energy while the honeycomb cells also help absorb impact. A study published last year showed that compared to standard helmets, AIM helmets resulted in a 14 percent reduction in linear acceleration and a 34 percent reduction in rotational acceleration.6 Another new technology is the use of impact-absorbing liners made from vinyl nitrile (VN), which is tested to absorb multiple impacts (it's typically used in football and hockey helmets). So far this material is only found in certain snow-sports helmets and has yet to migrate to bicycle helmets.

What About an Airbag for Your Head?

As part of a thesis project, two graduate students in Sweden stepped way outside the box with an entirely new concept in bicycle safety. They designed what is essentially an "airbag for your head" that inflates before your head hits the ground, car or other unforgiving object.7 The "Hovding" is worn like a somewhat poofy collar—nothing is on your head, so goodbye helmet hair!8 The company claims Hovding has three times the shock-absorbing capacity of a traditional helmet, which may greatly reduce your risk of serious injury. More than 200 sensors around the nylon hood measure your movement and inflate the helmet in one-tenth of a second—just prior to impact—using a helium gas inflator in the rear of the collar, as you can see in the video above.

The helmet is battery operated, and once the hood has inflated, the helmet must be retired... a definite downside, given its current price tag of about $400 (but if it saves your life, it's obviously priceless!). According to impact tests conducted by the Swedish insurance company Folksam, the airbag "helmet" seems promising:

"With a traditional cycle helmet in this type of accident, the likelihood of serious head injury is approximately 90% and the risk of a fatal injury is as high as 30%. The use of an airbag cycle helmet in the same accident dramatically reduces the risk of injury. The risk of serious head injury is then only 2% and the risk of a fatal injury almost non-existent."

The helmet even incorporates a "black box" that records 10 seconds of data on your movement patterns from an accident, which helps the company with further development. I am eagerly awaiting independent studies, as all of the research thus far has been funded and performed by the helmet manufacturer. But if independent safety studies hold up, this technology will be a real game-changer! For those of you who aren't interested in waiting for more research, the Hovding is now available for purchase online and at select retailers in Europe.

Are You in the Market for a Bicycle Helmet?

I do enjoy cycling but rarely ride now because I am too concerned about dying prematurely, as the cyclist nearly always loses in a car crash. However, if I were cycling, I would get one of the new helmets described in the featured article as soon as they become available. It truly sounds like life-saving technology. If you are a cyclist, I would encourage you to read the full article at Bicycling Magazine.9

But I do want to make clear that even the "standard" helmets are better than no helmet at all. There has been some controversy on this subject, including a 2007 study that showed drivers pass closer to bicyclists wearing helmets than they do to bicyclists with bare heads, increasing the chances of collision.10 However, should you be in an accident, wearing a helmet is likely to increase your chances of survival.

In fact, data from the Insurance Institute for Highway Safety (IIHS) showed that since 1998 more than 90 percent of the people who died in bicycle accidents weren't wearing helmets.11 There's no doubt that bicycle helmet technology is in need of a major update… but even the older technology is better than going bare. If you're in the market for a new helmet, however, you may want to keep an eye out for newer concussion-reducing technologies on the horizon. As Bicycling Magazine summed it up:12

"There may never be an improved government standard for bicycle helmets. Experts may never come to a consensus on a standard for testing the forces most closely associated with concussions. But one test can be administered now: the market test. After all, new technology costs more.

…This is the bike-helmet industry's ­air-bag moment. The new rotation-­dampening systems may not be perfect, but they are the biggest step forward in decades. The choices cyclists make with their money matter. You can pretend to protect your brain, or you can spend more money and get closer to actually doing it."