To Helmet, or Not to Helmet.

The New York Times has stirred some bike-related news with their recent article on bike helmets.  In short, the article suggests that countries with larger public buy-in to cycling (predominantly European countries) have that public participation because they don’t wear helmets.  To wit:

I rode all day at a modest clip, on both sides of the Seine, in the Latin Quarter, past the Louvre and along the Champs-Élysées, feeling exhilarated, not fearful. And I had tons of bareheaded bicycling company amid the Parisian traffic. One common denominator of successful bike programs around the world — from Paris to Barcelona to Guangzhou — is that almost no one wears a helmet, and there is no pressure to do so.

In the United States the notion that bike helmets promote health and safety by preventing head injuries is taken as pretty near God’s truth. Un-helmeted cyclists are regarded as irresponsible, like people who smoke. Cities are aggressive in helmet promotion.

But many European health experts have taken a very different view: Yes, there are studies that show that if you fall off a bicycle at a certain speed and hit your head, a helmet can reduce your risk of serious head injury. But such falls off bikes are rare — exceedingly so in mature urban cycling systems.

The article goes on to make arguments such as:

  1. The risk of obesity and heart disease that the public faces by not biking is far more dangerous than the risk of riding a bike without a helmet (and thus combatting obesity).
  2. More people are injured taking baths than riding bikes, so perhaps we should wear helmets while bathing.
  3. The actual risk of a head injury while biking is incredibly low, so why wear a helmet?
  4. Other countries with different cultures are accepting of riding bikes without helmets, so we should be too.

Ok–perhaps I’m being unfair to the author.  Read his piece and form your own conclusions.  (Some of his strawmen arguments are pretty silly.  More people are injured bathing than cycling?  Really?  Is that surprising?  Hopefully, just about everyone is bathing on a regular basis.  (PSA: If you’re not bathing, start doing so).  But is the vast majority of the population cycling on a regular basis?  Sadly, not.  So in terms of the total, raw number of injuries created…of course bathing should create more injuries.)

I can see the appeal of his argument.  Helmets can be hot.  They muss your hair.  They can look unfashionable. Blah, blah blah.  With a truly well-developed inner-city bike infrastructure, with relatively low-speed bike riding, are helmets necessary?  Probably not. It is probably possible to devise a safe, urban environment for low speed bike riding without helmets…particularly in cultures that are more accepting of bike riding.  So I can totally see the discussion about riding along the Seine at a modest pace without a helmet.  Sounds nice.

What I find odd, though, is how the story has been picked up by other forms of media (and by Facebook posters) who are now espousing that perhaps helmets are overrated.  Let’s have some anti-helmet bike rides, like motorcyclists do.  Hopefully, no one will die from a head injury in a fit of cosmic irony.  (If you don’t follow the link, it’s about a motorcyclist who was riding to a no-helmet protest, crashed, and died after cracking his head into the pavement).

I’m not going to go into “the helmet saved my life” stories–though the web is replete with them.  I’ve had a couple bad wipeouts, including several where a helmet has taken a shot for me, and I’ve lived to tell the tale.  For me, riding without a helmet is such an unnatural, foreign act that it’s actually hard to do.  When I’m in the saddle, riding without a helmet feels like riding without pants.  I suppose you could do it…but why?

Moreover, for the helmet haters out there, please remember that the force of a crash that is imparted upon your head significantly increases with speed.  Here’s an explanation of the calculations at work…but let’s say you’re riding your bike and crash, going over the bars and crashing into a brick wall.  (Improbable, yes.  But an unyielding brick wall is a lot easier to use for calculations than a smack and slide on pavement.  So I’m running with it). We’ll use a hypothetical 70kg (about 155#) rider.  The amount of ENERGY to be dissipated in a bike crash increases dramatically with speed.  A 70kg rider going at 10mph has about 700 Joules of energy.  If you increase the speed to 20mph, you increase the energy to about 2,800 Joules.  That’s energy that has to be dissipated if/when you crash.  (Note: I don’t do math.  I make absolutely no representations that those figures are accurate.  They may be wholly pulled out of thin air.  But faster does mean more force.)

I was just about to go into a long, complicated calculation of the kilonewtons of force generated by the crash, assuming either head impact on brick, or assuming helmet impact (with resulting partial crash absorption).  Suffice it to say that: 1) the discussion would be boring; 2) unless you’re doing a perfect dart into a wall, it would be misleading; and, 3) all it would really show is that the small amount of crash absorption (perhaps 2cm of give) that you get out of wearing a helmet has an amazing, dramatic, drastic impact on reducing the crash forces that your body feels.  I think I can get to the point here without having to run through those calculations.

The point:

In a…

  • Perfect cycling culture, where cyclists are respected by motorists,
  • And where cyclists only ride at modest speeds,
  • And where the infrastructure/roads/paths are designed to permit safe use by cyclists…

Helmets may not be as urgently necessary.  They likely would still have a result in reducing injuries and such, but the force at work is not as great, so the resulting injuries are not as great.

If you take away any of those assumptions, the math changes.  Go to a fit cyclist riding for exercise at 20mph, or ride in an imperfect environment, or an environment with hostile motorists, and the merit of helmets becomes much harder to dispute.  You, as a cyclist, can do everything right.  If you get whacked by a car, you need every possible advantage just to have a shot at surviving.  Not wearing a helmet…it just doesn’t make sense.

I would love to live in a perfect cycling environment, where casual cycling didn’t require helmets.  In the US, we’re a long ways from that happening.  And in my opinion (hey, it is my blog), suggesting that the problem with cycling in the US is too much insistence on helmet use…well, that’s irresponsible.  And frankly, if wearing a helmet is the only obstacle standing between you and riding a bike–well then, enjoy your Big Mac, and subsequent heart attack.  But please don’t go riding in public, on busy roads, without a helmet.  When you get hit by a car, the resulting publicity makes it harder for other cyclists everywhere.  It makes it harder for us to explain to our families why we ride (every time a local cyclist is killed, I receive half a dozen concerned emails questioning my riding), and it makes it harder for us to convince local governmental entities of the merits of building cycle-friendly infrastructure.  No one questions building another McDonalds–so pick your poison.


6 thoughts on “To Helmet, or Not to Helmet.

  1. Pingback: To Helmet, or Not to Helmet. | ridingagainstthegrain | Bicycle News Gator

  2. Your readers need a balanced view:

    1. Whether bicycle helmets do any good is argued among well-respected researchers, i.e., that bicycle helmets save lives should not be considered a fact–there are peer-reviewed articles that present evidence that they don’t do any good.

    2. There are major cycling organizations that are against helmet promotion, e.g., The European Cyclists’ Federation (cited in the NYT article) and One Street (based in D.C.). See the following:

    3. Bicycle helmet wearing among recreational riders only became widespread in the late 1980s/early 1990s. However, there is no evidence that head injuries decreased or that bicycling became safer in any way over that period. If all of the “helmet saved my life” anecdotes were true, there should have been an epidemic of head injuries before the Helmet Age set in, but there wasn’t. And I assure you that we rode just as hard and took just as many chances on bicycles before then as bicyclists do now and as kids, we rode much more than kids do now–you had to search for an open spot in the bicycle racks at my high school if you got there too late. See the following:

    4. Bicycle helmets absorb energy when they crush. When a helmet cracks, it is called “failure” in the industry–if it did not crush, it did not decrease the deceleration of the head (which means it didn’t absorb energy). That a bicycle helmet cracked doesn’t mean it save a life–a vent could been snagged as the helmet slid on the ground.

    5. There are theoretical mechanisms by which a bicycle helmet could increase the risk of head injury: 1. Snagging of the vents as the helmet slides along the along the ground could increase the rate of deceleration relative to what it would have been if the hair and scalp were sliding along the ground instead (motorcycle and football helmets have smooth sides and probably slide better along the ground than a bare head does). This increased rate of deceleration would result in increased energy being imparted to the brain. 2. There is good evidence that rotational forces are the major forces that cause brain injury. Think about how much your neck would bend if you fell backwards with and without a helmet on.

    There is much more. The important point is that it is not written in stone that bicycle helmets save lives.

    • Disclaimers first: I’m not a journalist. I’m a blogger. I don’t profess to have a fair and balanced view. I give my thoughts on subjects…that’s the nature of blogging. The closest I come to journalistic integrity is product reviews, where I do try very hard to be objective and provide the info that I’d want as a consumer. But otherwise, it’s all my opinion on schtuff. That’s the beauty of a blog.

      That point aside, here’s my spattering of responses:

      1. Certainly helmets are not a panacea. They will not save every life, prevent every brain injury, or ensure that your toast always falls butter side up.

      2. I don’t think there can be any legitimate argument that riding with helmets is more dangerous than riding without helmets. I looked through each of the works you cited, and did not find any compelling arguments that helmets add danger to cycling, except to the extent that an increased perception of invulnerability causes people to take stupid risks. So helmets cannot fix stupid. But here’s the NYTimes article you quoted:

      What is going on here? No one is very sure, but safety experts stress that while helmets do not prevent accidents from happening, they are extremely effective at reducing the severity of head injuries when they do occur. Almost no one suggests that riders should stop wearing helmets, which researchers have found can reduce the severity of brain injuries by as much as 88 percent.

      Of note, that article doesn’t analyze accident severity, except to note that helmets reduce brain injury severity by as much as 88%. The “increase in head injuries” could be an increase in the number of low severity accidents that get reported. When I was a kid, I fell off my bike all of the time–the only time I went to the ER was the one time I actually cracked my head open. Nowadays, many parents rush to the ER and demand a CT scan for even the lowest intensity injuries. Is it an ‘increase in head injuries’ because more injuries are reported and treated, regardless of severity?

      3. Anecdotal/Personal evidence: I have personally had at least half a dozen falls where a helmet has prevented a more severe injury–whether by virtue of taking the impact of whacking into a tree (where one helmet did crush, as you’ve noted, and thus dissipated energy by crushing instead of having my hard skull hit a hard tree), or by virtue of sliding along the dirt or gravel and letting my helmet get scratched, instead of sliding along on my scalp or ear. That may not be enough to convince anyone else–but it’s all I need.

      4. Anecdotal/Professional evidence: I worked as a volunteer EMT for several years. In that time, I had a chance to treat injured cyclists who had road rash on their shoulders/arms/legs/etc., but whose heads were perfectly intact and uninjured–because they wore helmets. And their helmets bore out that observation, with scrapes/scratches/rash that would otherwise have been on their heads. Separately, while at a much higher speed, I had a chance to work on a number of motorcycle accidents. Motorcycle helmets obviously offer slightly different protection, but there was a dramatic difference in crash outcomes, from similar types of crashes, based on whether the riders were or were not wearing helmets. Absolutely no doubt.

      I’m not claiming my experience covers the whole country or is statistically significant. But I fundamentally do not understand advocating for less helmet use. If the possibility of wearing a helmet dissuades someone from cycling, so be it. I don’t apologize for that position. I wear a helmet, my wife wears a helmet and, most importantly, my daughter does and will wear a helmet.

      I’ve discussed the argument that helmets are dangerous because they dissuade cycling, thus resulting in a fat population that dies from a MI. I’m ok with that outcome–if a helmet is that big of a disincentive to you that you won’t ride, well…enjoy your bacon.

      I’m not suggesting mandatory helmet laws. If you want to ride and crack your head open, go ahead. I am, however, suggesting that anti-helmet public education campaigns (arguing that helmets are unnecessary) would be misinformed and poorly reasoned..

      Frankly, I have a hard time taking seriously the argument that helmets are more dangerous than riding without a helmet. Is it possible to construct some sort of argument that a helmet can cause an injury? Sure…the visor on a MTB helmet fails to snap off, and hits the ground snapping your neck back and breaking your neck. Likelihood that an accident will occur where a helmet increases accident severity? Without the benefit of statistical analysis, common sense tells me that’s very, very improbable.

      There are accidents that will be fatal no matter what. Undoubtedly. But I disagree with your bottom line assertion. I have yet to see a study that concludes that helmets do not have a role in reducing the severity of injuries and/or preventing fatalities. Even the studies you cite…

  3. Most bicyclists I know assume that the evidence for helmets is incontrovertible; I just wanted to point out that it is not. This is a topic that is near and dear to me, because I love cycling and I have seen cycling hurt so much in my lifetime by the promotion of the idea that you are crazy to ride without a helmet. I would like to address this issue fully myself, but unfortunately I don’t have time.

    Here is a source for counterpoints to bicycle helmet safety arguments:

    Here is a source that presents both sides of the story:

  4. I live in Barcelona area (Spain). The helmet is not mandatory in the city but yes on the road. This is because “bicing” service (urban bike rent service) could have less users if helmet use was mandatory on urban area.

    I always wear my helmet!!!!

  5. Left to my own devices I don’t need or want to wear a bike helmet for most of my casual city riding. I don’t wear a helmet in the shower and that’s just as dangerous in terms of a head injury as tootling down the road for an espresso.

    OTOH – I do wear a helmet every time I mountain bike and when I do fast paced group cycling events on the road. I happen to crash frequently enough under these circumstances that a skid lid makes sense to me.

    Ultimately I think mandatory bike helmet laws do more harm to society in reducing participation in cycling than they do reducing brain injuries.

    safe riding,


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