Use your head while riding

Warning – Just Another Cyclist is about to jump into the cycling helmet debate.  If you’ve had about all you can stand of the endless arguing on this issue (and who can blame you really?) then perhaps you’ll find one of my other articles more to your taste.

I also want to point out that you will likely not walk away with a clear impression that I’m on one side of the issue or the other.  I’m decidedly neither pro nor anti helmet.  I wear a helmet when I ride if I feel like it.  I generally always wear it on group rides more out of peer pressure (everybody’s wearing one!) or habit than anything else.  I almost always wear gloves when I ride to protect my hands if (or should I say when) I happen to hit the pavement, and the helmet is kinda in the same category.  On the other hand, I do not ride any differently if I don’t have my helmet on than when I do.

The main reason for my indecision is that I’ve not seen anything that would make me think that one side of the argument or the other is correct.  I decided to do a little more digging into the issue and see what I could come up with.

Photo courtesy of Richard Masoner, http://www.cyclelicio.us/ used with permission

I started this exercise by doing an online survey to try and get a sense of what my readers and associates actually think about helmets.  If you are the data-hungry type, ou can read the raw results of the September 2010 Bicycle Helmet Survey here in pdf format.  The helmet debate is like many things in human society – you tend to only hear the opinions of the folks on the far extremes of either side of the debate.  I wanted to know what “average folk” thought.  The results were some questions posed to readers.

So let us begin our look at the issue.   The results of the survey are probably no surprise to anyone living and riding a bike in the United States.  The overwhelming majority – over 80% of respondents – are wearing their helmets pretty much all the time.  It is interesting to note that 89.4% feel that bike helmets make them safer, while slightly less (80.9%) feel that a bike helmet will actually protect them in a crash.  There was also a small but significant percentage (14.9%) that were undecided on the protection offered by a helmet in the event of a crash.

I’m sure there are some of you that are surprised that only about 80% seem to think a helmet will protect them.  “Isn’t it obvious that a helmet would protect you in a crash?” you may ask.  “That’s just common sense!” Well in fact, from a purely objective standpoint, it is not so obvious.  Wearing a helmet is one of those things that just feels intuitively like the right answer.  If I put something on my head, then my head is protected if I smack into something.  It is, in fact, apparent that helmets can help from things like skull lacerations – nicks and cuts in the skin when you bump your head into a tree branch, or another bike, or the road.  But that is generally not what helmets are supposed to protect us against.  Rather, helmets are perceived to help protect from catastrophic injuries – concussions, skull fractures and the like.  And here is where the issue gets decisive: there actually is absolutely no evidence that a helmet provides any meaningful protection from concussions or skull fractures. In fact there is some evidence to the contrary – that perhaps wearing a helmet makes you actually more likely to sustain a significant head injury.  But before we get into the details of making things potentially more dangerous, lets dive a little more into the protection factor.

Indeed, regarding concussions specifically, an article published by the Bicycle Helmet Saftey Institute (BHSI) states:

The vast majority of consumers assume that a helmet should prevent concussion in even the heaviest hits, and that if the helmet protects against severe blows it must surely be easily protective in lesser ones. But in fact the helmets built to our standards are in many cases too hard to protect against a mild concussion in either a low speed hit where foam fails to crush or a much harder hit where clinically evident permanent injury is avoided, but a lesser concussion still results even though the helmet has not crushed completely and bottomed out.

For some the idea of needing a “softer” helmet may seem counter intuitive.  In the context of concussions, though, it is absolutely critical.  To understand concussions, let’s consider what happens to our bodies in an automobile crash.  Most of us have probably seen the slow-motion crash test dummy videos of car crash tests, so you’ll understand how, when the car stops suddenly due to striking something, the driver can continue forward and slam into the dash board.  This is why seatbelts are effective – they help restrain the driver and reduce the force with which the strike other objects in the car.  It is also why cars are now constructed with crumble zones – areas of the chassis of the car that are specifically designed to absorb the energy of the moving car and slow the deceleration of a vehicle when it hits another object.

Photo courtesy of Richard Masoner, http://www.cyclelicio.us/ used with permission

A concussion occurs when our brain impacts the inside of our skull due to the same mechanics.  In other words, using our car and driver example above, the car is our skull and the driver is our brain.  To reduce or eliminate concussion injuries, we need to prevent the brain from slamming against the inside of our skulls when our skulls unfortunately slam into something else at high speed.  Since we obviously can not strap our brains in with a seatbelt, we are left with the option of creating a “crumple zone” around our skull to absorb some of the impact.  Helmets theoretically provide that crumple zone for us.

In my survey, just over half of the respondents agreed with the statement “Helmets clearly protect you in a crash”, while only a single respondent agreed with the statement “There is no evidence that helmets will protect you in a crash.”  The citation above (from BHSI) was from a report targeting making helmets safer, and itself raised questions about the effectiveness of helmets as the standards currently dictate their design.  The fact that just less than half of respondents to the JustAnotherCyclist survey did not select “Helmets clearly protect you…” would seem to indicate a general ambiguity about what, if any, protection is provided among the survey takers as well.

This kind of gets us to the issue – the actual, subjective data is lacking.  Further more, that lack of data combined with human behavior naturally skews our impressions in one direction, in favor of helmets.  Consider the situation where a cyclist gets critically injured or even killed and isn’t wearing a helmet at the time.  It is very easy to claim “If only he’d been wearing a helmet…”  Furthermore, when a serious head injury happens and the cyclist was wearing a helmet, the natural inclination is to think “The helmet saved her life.  Imagine what would have happened if she hadn’t been wearing it…”

You see, we can’t derive real, actual data from specific crashes because we can’t test both sides of the hypothesis.  We can’t see the outcome of a crash without a helmet, and then take the cyclist, put a helmet on them and completely recreate the same exact crash and compare the results.  What we can do, however, is look at overall statistics and see if the rate of serious head injuries among cyclists is higher in areas where helmets are either mandated by law, or commonly used by convention.

And guess what – on the surface helmet usage seems to actually increase your liklihood of a head injury -purely by the numbers.  The Netherlands is often used in these comparisons.  They have an extremely high percentage of trips taken by bicycle – the highest in the world.  They also, as a cultural norm, pretty much never wear helmets.  In contrast, the United States has a much lower percentage of trips taken by bike, with almost ubiquitous helmet usage.  In stark contrast to what common sense might tell us, the United States has a significantly higher percentage of head injuries per cyclist than the Netherlands.  We must also take into account, however, the environment of each country.  In a country where bicycles are the predominate form of transportation, it is possible that folks are just better and safer riders.  It is possible that cars are more aware of cyclists and don’t hit them as much.  It is also entirely possible that the Netherlands has more “casual” cycling – i.e. cycling at slow speeds – and thus has an overall reduced risk of serious head injury.  Or it could just be that helmets somehow elevate our risk of head injuries.

Further muddying the waters are studies that demonstrate the opposite.  For example, you can find the following chart in a 2008 publication of the Insurance Institute for Highway Saftey

Bicyclist deaths by helmet use, 1998-2008
Year No helmet use Helmet use Total*
Num % Num % Num
1998 741 98 16 2 757
1999 698 93 42 6 750
2000 622 90 50 7 689
2001 616 84 60 8 729
2002 589 89 54 8 663
2003 535 85 58 9 626
2004 602 83 87 12 722
2005 676 86 77 10 784
2006 730 95 37 5 769
2007 646 92 50 7 699
2008 653 91 58 8 714
*Total includes other and/or unknowns

And there is what is often cited as the most definitive study, A case-control study of the effectiveness of bicycle safety helmets. (Thompson RS, Rivara FP, Thompson DC.)  This study claims as much as an 85% reduction in head injuries by wearing a helmet.  The study does have its detractors, however.  It was at least partially funded by a helmet manufacturer (Snell) which presents a potential conflict of interests.  For example, the Bicycle Helmet Research Foundation goes into some details in their counterargument to the study.

At this point – let’s take a leap and conceed that “OK – so we don’t have any idea if helmets help or not.  Clearly they can not hurt, right?”

Wrong.  Or at least according to Dr. Ian Walker.  His research  – conducted in the UK in 2006 – seems to indicated that motorists may actually drive closer to cyclists wearing helmets compared to non-helmeted cyclists.  Or, said another way, there may actually be more likelihood of a collision with a motor vehicle when you are wearing your helmet than when you are not.  There is also an often cited human behavior where, on the whole, folks are more apt to engage in risky behavior when using safety equipment than when not.  There was a question in the JustAnotherCyclist study that was intended to capture this latter point explicitly – and in fact 17.9% selected the statement “I change my riding (slower, different routes) if I don’t have my helmet” as a statement that fit them.  This would seem to agree with the idea that people do not necessarily show the same level of caution when they use safety equipment (such as helmets), presumably assuming that the safety equipment mitigates the increased risk.

Photo courtesy of Richard Masoner, http://www.cyclelicio.us/ used with permission

I invite you to look over the data – from the JustAnotherCyclist survey and other sources – and draw your own conclusions.  I will not put forth a particular opinion one way or the other.  I believe that, in the lack of subjective data supporting either position, wearing a helmet or not is an entirely personal choice.

I do, however, encourage tolerance and acceptance in the cycling community.  Stop the peer pressure and divisive comments between wearers and non-wearers.  Instead, let’s all unite to help make cycling safer over all.  Avoiding a crash entirely is undeniably more effective at prevent injury than any safety equipment imaginable.  Let’s work to make the roads safer for all non-auto users and not alienate cyclists into “helmet” and “no-helmet” camps.  Us cyclists already spend too much time dividing ourselves up into subgroups.  Let’s leave this debate to the scientific community to sort out and just keep pedaling, eh?

  • Brent

    I would be curious to see a “crash test dummy” report on helmet effectiveness. The standards now are rather silly: the testing agency essentially puts a weight in the helmet and drops it against a surface. Why couldn’t some smart scientist invent some more real-world test, say, put a dummy on a bicycle, accelerate it into a wall, and see what happens?

    • http://justanothercyclist.com/ JustAnotherCyclist

      That’s a really good point. My understand is that the very first study done that essentially established the current standards – back in the 1950’s I believe – were done with cadavers. However, the study has not apparently been reviewed or updated since then.

      • Brent

        A few weeks ago I did a tour of a few helmet manufacturer’s websites in hopes of gleaning their take on the safety of their products. None of the sites have much of anything, other than the occasional mention that the helmet meets applicable safety standards. It’s almost as they don’t really believe in their own products. Most of them do, however, tout their “massive airflow” or similar.

        I find interesting the contrast to some automobile manufacturers, who go out of their way to show the ways in which they exceed safety standards, and in some cases promote their products with crash videos.

        • http://justanothercyclist.com/ JustAnotherCyclist

          That is a really interesting angle on this. I spent a fair amount of time trying to get at, exactly, what those “applicable saftey standards” are. I found a lot of things that make reference to the, but I could not locate that actual requirements for the United States.

  • Eric

    I see this as a question of which is a more effective strategy to reduce the danger: armor or avoidance.

    Body armor means you’ll bounce off thing you hit. Better bike handling skills means not coming off the bike. My helmet is a small step toward the reducing the damage when I fall off. The term “header” was made for the most common of bicycle accidents. More armor – not very useful – just my bike gloves and unbreakable Oakleys…

    Not riding into the path of a car would be considered good bike handling. A more Zen approach to traffic seems the best. I don’t expect the helmet to make me safe from cars ( or speeds over 20 mph for that matter ). Safety really come down to bike control – where are you riding in traffic?

  • Stanford Tran

    I was a collegiate racer during undergrad and now that I’m in med school, my classmates give me a hard time for not wearing a helmet. So I decided to find conclusive evidence regarding helmet usage. This study in the New England Journal of Medicine, which corrected for income, education, level of cycling experience, etc., shows that it is without a doubt beneficial to wear a helmet. Granted it’s from 1989, I don’t see why it wouldn’t be true today. http://www.nejm.org/doi/full/10.1056/nejm198905253202101

    Not sure if I will start wearing a helmet myself, but I feel less hypocritical encouraging my patients to do so.