Children and helmets

Whenever children's road safety or cycling are mentioned, the subject of cycle helmets is invariably raised. Not just raised, either - in many cases helmet promotion is the beginning, middle and end of all discussion about cycle safety. I strongly believe that in this monomania for helmet promotion, the fundamentals have been forgotten. A recent news report referring to a cycle safety programme which turned out to consist solely of lockers for helmets illustrates my point: how many crashes will those lockers prevent? I am not against the use of cycle helmets but I strongly believe that a dose of reality is called for.

Should I make my child wear a helmet? If so, how?
That's probably what you came here looking for. And the answer to that is: it's up to you. I personally believe that helmets have good potential to reduce minor injuries caused in simple falls, so are more likely to do some good in a toddler learning to ride than in a teenager riding on the road. Elbow and knee pads are also good for toddlers until they become competent.

Once a child reaches adolescence, you can't force them to do anything much: you have to make a decent case to them and let them make up their own mind. Giving them a hard sell is often guaranteed to have precisely the opposite of the desired effect, of course. One story in the press had the local MP opening a "cycle safety initiative" at a school; it turned out to consist of helmet lockers and nothing else. Kids are amazingly good at sniffing out this kind of bogus initiative, and I reckon the more schools make a huge deal out of helmets, the more it will be cool to be a rebel and no wear one.

It is also the case that children will take more risks when wearing a helmet than not - this is perfectly normal. It is probably not a coincidence that the one area where hard-shell helmets are still common (and cool) is BMX stunt riding. So overstating the benefits of helmets - the hard sell so common from single-issue campaigners - may well be counter productive. I can see no good result from giving children an inflated idea of the protective capability of a device which is not, after all, designed for the most common sources of serious and fatal injuries.

OK, now I'll pin my colours to the mast: should you force your child to wear a helmet? Of course not. They will get more benefit our of riding a bike without one, than out of not riding a bike. If that's the choice you;re giving them, then they would be smart to opt for the former. Should you encourage them to wear one? Why not, as long as you are really careful not to make a big deal about it. I saw a parent the other day running screaming after her child because he was riding around on a grassy field without his helmet. Kids have been falling at running speeds onto soft grass for millennia and the race has not yet died out - chill out, get a sense of perspective. And remember you child psychology - think of the helmet as a giant plastic Brussels sprout.

How dare you not advocate helmet use by children!
Let your kid ride a bike without a foam hat these days and some people will treat you as if you are a child molester! Where do they get off? No, it is not "essential kit", and never was. And here's why:

Cycling is not dangerous.
This is true on a number of levels. First, while the helmet promoters bandy about some scary-looking figures, if you review them critically they include mainly the kinds of minor bumps and scrapes which, in a more innocent age, we took as a normal part of growing up. Figures for more serious injuries are very much lower, and tiny by comparison with the major source of hospitalisations in children - trips and falls.

Second, cycling confers distinct health benefits. We all know about the rise of obesity, and concerns about the effects of inactive lifestyles, and there is good evidence that cycling is not just beneficial to health, but unusually beneficial. Even otherwise fit people gain a health benefit by using cycles for transport, because it integrates moderate cardiovascular exercise into daily living. One estimate puts the ratio of benefit to risk as high as 20:1, and the consensus is that regular cyclists generally live longer and have better health.

Third, cycling is not the source of danger. Of course there are risks - you can hit a tree root or pothole and fall off - but the majority of serious injuries and virtually all deaths to child cyclists are the result of crashes involving motor traffic. This is even more true for child pedestrians.

Cycling is not especially likely to result in a head injury.
Hospital admission figures from the Department of Health specifically relating to children in England show that the proportion which are due to head injury is typical of that for all injuries. The proportion for pedestrian injuries is much higher, but this only includes road traffic injuries. Comparing like with like, here, too, the figures are similar. It is said that 70% of cyclist deaths are due to head injury, but not only is that contentious (the figure is known to be around half for children, and a quarter of all cyclists killed are crushed by left-turning lorries), even if it were true that would be typical for impact deaths. In short, I know of no evidence to suggest that cycling crashes are unusually productive of head injuries.

Child safety: start here
While there is no evidence to suggest that cycling is unusually dangerous or unusually likely to produce head injury, the same is not true of car use. Road traffic collisions account for a tiny proportion of all child injuries, but one in ten of those serious enough to be admitted to hospital and half of all fatalities. Of all road user groups cyclists are actually the least likely to be to blame when injured or killed by a motorist.

We must never lose sight of the fact that our transport choices, as adults, exert a far greater influence over our children's health, short term and long term, than theirs do.

Cycling can be safer
Just because cycling is not dangerous doesn't mean it can't be safer. There are a lot of things which are thought to improve cyclist safety, of which helmet use is arguably one. But road safety experts and doctors alike have placed helmets last on the list of possible actions, mainly because trying to reduce the effects of a crash is always less effective than preventing it in the first place.

There was a widely publicised case recently where a teenager died of a head injury after riding off the pavement into the path of a car on a bike with defective brakes. If you or I were to rank the interventions likely to prevent this tragedy we might debate briefly over the relative importance of fixing the brakes and not riding on the pavement (or more to the point not riding off it at junctions), and maybe whether turning traffic is always going slowly enough to stop if someone does step out into the road, but I hope you would agree that it is perverse to suggest, as some did, that the lack of a cycle helmet was the critical factor.

There are a few things which I believe do make cycling safer, based on evidence from various trials and various countries:


 * more people cycling seems to be the best predictor of cycling safety
 * lower motor traffic speeds is also a key factor, with the 30kmh (19mph) zones in much of continental Europe showing a consistent reduction in cyclist and pedestrian fatalities
 * training is vital to ensure that cyclists avoid common traps like riding up the left side of turning vehicles, riding too far to the left (which encourages close overtaking) and so on.

Things are not always what they seem
Many measures which are assumed to improve safety, like high visibility clothing, cycle facilities, lights and helmets, turn out to be much less clear-cut. It is amazingly difficult to find robust evidence that these things make any appreciable difference at all, in fact, and some (like some kinds of cycle path) definitely make matters worse.

If that seems strange to you, consider the case of a measure which I would suggest is pretty uncontroversial: compulsory use of seat belts. It turns out that the Department of Transport, as was, actually had a report in their hands before the seat belt law was passed which showed that the road safety records of countries which had introduced seat belt laws had not improved as a result.Although drivers were somewhat less likely to be injured in a crash, they were somewhat more likely to crash in the first place because they responded to the feeling of safety by driving slightly less carefully. Road crashes are a bit like walking along a cliff-edge: the closer to the edge you walk, the more likely you are to fall off; one former transport minister put it very succinctly: "[crashes] are caused in the main not by the taking of large risks, but by the taking of small risks very large numbers of times".

But no net change in injuries is not the whole story. It turns out that while there was no reduction in the overall number of people killed and injured, there was a shift in the balance. The number of pedestrian, cyclist and rear passenger fatalities rose sharply, while the number of driver fatalities fell - the seat belt law protected those causing danger at the expense of their victims. The same phenomenon was documented in a carefully designed study of driver responses to ABS brakes and is being seen again now with the arrival in the hands of young male drivers of cars with driver's side airbags, which has been associated with a significant rise in the front passenger fatality rate. And put like this it is obvious: when we see ourselves as safer, we relax. Sometimes, as with ABS brakes, the perception of the safety benefit is so accurate that this relaxation precisely cancels the benefit. In other cases, such as motorcycle helmets, we appear to overcompensate, so risk rises slightly.

What cycle helmets are not
To get back to the subject, there are a number of false perceptions about cycle helmets which need to be got out of the way.

Cycle helmets are not a road safety measure
We know this because when road safety departments have passed laws requiring cyclists to wear helmets, the proportion of injured cyclists who have head injuries remains constant, however steep the rise in helmet use. Probably the most extreme and best-studied example is New Zealand, where helmet use rose from under 45% to over 90% in one year, and the cyclist head injury trend (for several years before and after, in fact) was indistinguishable from that of pedestrians. Helmets are not a road safety measure because they have been shown to make no difference to road safety.

A moment's rational thought reveals the reason for this, which is that helmets are not designed to be a road safety device. Most cyclists who are injured or killed are hit by motor vehicles. The energies involved generally exceed the capabilities of the best competition motor racing helmets, and those who die of head injury very often have other mortal injuries as well. Helmets are designed and tested for low-speed falls, and expecting them to provide meaningful protection in more serious crashes is simply foolish.

Cycle helmets are not a cycle safety measure
Following an extensive review in 2002 the Road Safety Minister, David Jamieson, said in a letter to Michael Jack, MP, that the Government knew of no instance where cyclist safety had improved through increased helmet use. And the reason is the same again: the majority of injuries and fatalities come from a source which greatly exceeds the limited capacity of helmets.

Cycle helmets do not save lives
The idea that 3/4" of polystyrene foam can save you when hit by two tonnes of metal is so absurd that you rather wonder why so many people believe it. Would you expect your computer to survive being hit by a car if you put it in its box with its foam packaging? Of course helmets don't save lives, they are not designed to, and none of the manufacturers claim they do. Some studies claim that helmets do save lives, others show that helmeted cyclists are more likely to die. I believe that helmets are essentially irrelevant in potentially fatal crashes.

Every now and then we see stories in the press of people holding up a broken helmet and claiming it saved their life. I have news for them: their helmet failed. Cycle helmets are designed to compress, absorbing impact to reduce linear deceleration, and to do this they must remain in one piece. Polystyrene foam absorbs very little energy in brittle failure. Although nobody knows in any given case how much energy is absorbed before the helmet fails, it is likely quite small, the force is applied in one large shock loading, so failure will be pretty much immediate. For these reasons any helmet which shatters during standards testing (as many do) will fail the test. People also assume standards have improved over time, like car secondary safety. They haven't - the reverse is true, they have been reduced over time in response to market demands for lighter and less sweaty helmets. Few now on sale will meet the "gold standard" of Snell B90 or B95 certification.

On the plus side, cycling is not actually that dangerous anyway - the number of "helmet saved my life" anecdotes greatly outweighs the number of cyclists who died before helmets came along and the idea that all cycling crashes are inevitably fatal if you are not wearing a helmet is as silly as the notion that a thin polystyrene shell represents the difference between life and death. We are expected to believe that every rider who dies would have lived had he worn a helmet, and every helmeted rider who survives would have died without. Given that the bicycle has been around for around 150 years, and helmets for about twenty, that is an improbable conclusion.

Cycle helmets do not "prevent 85% of injuries"
You can't spend long looking into the subject of helmets without the figure 85% being mentioned. Just about every helmet promoter quotes either this or the accompanying figure from the same study, 88% of brain injuries. The latter should alert you straight away: how credible is it that a cycle helmet would be more effective against brain injury than against cuts and bruises? But that is what is claimed.

One reason these figures are misleading is that the definition of head injury and brain injury is never stated by those quoting them. Head injury brings visions of unconsciousness and skull fractures, and brain injury raises the dreadful prospect of permanent intellectual disablement. In the studies, "head injuries" are mostly cuts requiring only dressing (if that), and the "brain injuries" are almost all simple concussions.

But that is just scratching the surface. I spent some time looking into the 85% claim, and this is what I found:


 * It arrived at the figure by comparing injured "cases" (mainly black male working-class male youths riding alone on city streets) with entirely different "controls" (mainly white middle-class, slightly more female than male, riding with families on leisure bike trails) and attributing all the difference to helmet use.
 * It assumed that the helmet wearing rate of the "control" group was typical for those street cyclists who were uninjured, whereas one of the authors had conducted street counts which showed this was not the case. Just substituting Rivara's street counts for helmet use reduces the calculated benefit to zero within the limits of statistical error.
 * It claimed reductions in parts of the head not covered by helmets, rather than recognising these as evidence of confounding factors within the data.
 * It used very small numbers of cases.
 * Using the same figures it can be shown that helmets prevent 75% of broken legs.
 * When the above errors were pointed out to them, the authors agreed that the figure was not supportable from the evidence but continued to assert that the figures were correct, even though they have subsequently failed on several occasions to match them.
 * It is evident that the authors had already decided on the outcome before starting the research (as is often the case in science generally). They were already among the strongest advocates of helmets in the world before they counted a single head.
 * Finally, the report does not in any case show that helmets prevent some proportion of injuries, it shows that helmeted riders are less likely to suffer a head injury, which is not the same thing at all. If risk-averse cyclists are most likely to wear helmets (as seems likely) there is an obvious potential source of bias.

I found out another important thing: all the above is well-known to helmet promoters and researchers, but they continue to quote the figure anyway, knowing full well it is unsupportable. One helmet promoter told me: "the figure is so ingrained in the injury prevention community that a change would not be helpful". Does that sound to you like "don't confuse them with the facts"? I think that when discussing safety issues facts and realities are slightly more important than being "helpful" to those who have already decided on a particular course of action.

Of course this is not the only study. There are lots of others, and the range of efficacy estimates is between about -15% and +90%. Most of the pro-helmet studies, though, share a common design: patterns of injury in helmeted and unhelmeted cyclists are compared, and the difference attributed to helmet use. But what if helmet wearing is an effect, not a cause? This is what I mean: over a period of years, researchers noticed that women undergoing hormone replacement therapy (HRT) were less likely to suffer coronary heart disease (CHD). The finding was significant and repeatable across many studies. Meta-analyses were published (attempts to make a large, i.e. statistically significant sample by combining lots of small samples). An orthodox view developed that HRT prevented CHD, and a mechanism was suggested by which that might happen. Randomised clinical trials were undertaken. When the results were analysed it was found that those women on HRT had a small but significant increase in risk of CHD - the exact opposite of what had been predicted. It turns out that the women on HRT were from a higher than average socio-economic group, more likely to have good diet and exercise habits. Just as with the Seattle helmet study the case and control groups turned out to be different, and it was this difference which, as it were, made the difference.

Quoting an inflated figure for efficacy is not the only way we are misled about what helmets do. Often the same figure is used to predict savings in serious and fatal injuries. Why? Do you think that something which prevents, say, half of all minor injuries will also prevent half of all deaths? This makes no sense! By quoting a figure which, even if it were correct, would apply to all injuries of all severities, and then talking in terms of sever and fatal injuries, we are deluded into thinking that the efficacy figure applies to the injuries under discussion, which it plainly doesn't.

Cycle helmets are not without drawbacks
There is a tendency to think that, even if we don't believe all the hype, there can't be anything wrong with wearing a helmet. This is not true.


 * Research shows that children who wear helmets are more willing to take risks.
 * Helmet promotion campaigns usually rely on talking up the dangers of cycling which can often have the effect of simply putting them off altogether. This worsens overall health and reduces the safety-in-numbers benefit which is one of the few things which is consistently found to improve safety.
 * Some specialists claim that helmets worsen the twisting motions implicated in causing the most serious brain injuries.
 * There is anecdotal evidence that drivers are prepared to take more risks around a cyclist they believe is better protected.

I would treat some of this with caution: the helmet strap fatalities are few in number and there is no evidence specifically linking helmets with actual increases in rotational traumatic brain injury, but there is every reason to believe that children who are told to wear a helmet because it will prevent what to a first approximation looks like all injuries, will behave differently as a result.

What cycle helmets do
OK, enough of the knocking copy. I first started wearing a cycle helmet in about 1985, and even though I have now corrected my assumptions about what they can do I still often wear one. Here is what I believe helmets are good for:

They prevent bumps and scrapes and possibly even concussion Without a doubt they do a good job of that, although there have been comments that for the smallest children the bulk and weight of the helmet might cause balance problems, and for all riders the larger size of the helmet means that judgment of overhead clearance is often disturbed - you bang your head on a low branch and think "glad I was wearing a helmet" but if you hadn't been wearing one you'd probably have missed it anyway.

But all those reports of umpteen percent of injuries saved undoubtedly have a basis in fact, in that the kinds of cuts and bruises you can get falling off a bike are very often prevented. Of course these are not life-threatening injuries, but they can be distressing. The same applies for concussion. It is quite possible that helmets can prevent many cases of concussion. We can call these head injuries, lacerations, contusions, brain injuries, but the fact remains that for the most part the ones preventable by helmets are not especially serious, and nobody has even tried to see how many of those "helmet-preventable" injuries might equally be avoided by any decent hat. This is quibbling, of course. My usual advice is: by all means wear a helmet, but remember it is made of meringue covered in eggshell and ride accordingly.