Maxi-faq-helmets

Are you sure you want to ask this question?

OK, I assume you have come here for a reason. You have read the Mini-FAQ, which is deliberately non-confrontational, and you want more. More what? This page is not polemic, but nor is it guaranteed to be wholly free of bias, since I find that my reading of most helmet reports is coloured somewhat by my understanding of the previous ones. If you don't trust me and you don't trust BHIT (wise!) then you have only one option: to find and read as much of the source data as you can. I give you fair warning: this will take a while. My helmet resource is far from complete, and it contains over 700 documents of one sort and another.

And I have to be honest here, this is not so much a helmet FAQ as a helmet scepticism FAQ. It is an explanation of why scepticism is a valid view, as much as a look at the evidence. But then, I make no pretence to being anything other than a sceptic.

OK, hit me with it
Right, so the health warning has been ignored and you're still here. I'm going to divide the document up into chunks, in line with standard elephant-eating procedure. In many cases the situation for children is somewhat different to that for adults, and many helmet laws (and most helmet campaigns) cover only children, so the case for children is considered separately in some places.

You will see a lot of statistics. &quot;Aha!&quot; you will think, &quot;Statistics are like bikinis: What they reveal is interesting, but what they hide may be vital.&quot;And you will be right. So I've tried to give some of the background. So this page violates another mildly sexist axiom, that web pages, like skirts, should be long enough to cover everything important, but short enough to remain interesting. This page is long. It's long because there are no short answers. Well, I suppose there is a short answer to the question &quot;are helmets a good thing?&quot; and that is &quot;yes and no&quot;.

Risks of cycling
All discussion of the benefits or otherwise of helmets hinges on the perceived risk inherent in cycling. So, with shamelessly Anglocentric emphasis, here are some of the key figures.

You may note that the real figures do not always match up to the claims made by helmet promoters. I do not know why they exaggerate the risks - I have my suspicions, but Hanlon's Razor states that one should never attribute to malice that which can be adequately explained by incompetence. Reply on 10th November 2003 by Dr Ladyman, Dept of Health Minister, to Parliamentary Question by Brian Jenkins MP. Hansard Written Answers, 10th Nov 2003 page 17-8W

You may have seen other claims. BHIT claim fifty children die of cycling-related head injuries annually, based on an anonymous citation of a Hansard report; this is doubly false since the year in question was 1996, a peak year for deaths in an otherwise reducing trend (see above), and the figure quoted was for all deaths. They have subsequently said that this is &quot;an estimate based on under-reporting&quot; but there is no known evidence to support the idea of substantial - or indeed any - under-reporting of child cyclist deaths. The number of off-road deaths is tiny - one for 2003, I understand - and under-reporting of fatal cyclist road accidents is 0%, according to the TRL.

Eric Martlew says: &quot;It is estimated that about 30 children a year get killed on cycles and the lives of 12 of them could be saved if we had compulsory helmets.&quot; (BBC). Here, too, he is clearly wrong, since his estimate for lives saved exceeds the total number dying of head injuries. There is no figure for how many of those had other mortal injuries as well, as would be common in cyclist v. motor vehicle crashes.



How many people are injured cycling every year? 

There are two common measures of numbers injured, that for serious injury and that for all injury. It is recognised that reporting rates are lower for less serious injuries, with non-reporting rare for fatalities but relatively common for trivial injuries, especially off road.

HASS/LASS gives a figure of around 132,000 injuries of all severities from leisure cycling treated in hospitals, GP clinics and minor injury units, and notes that up to four injuries may be recorded per treatment event.

DfT figures give 1,776 adult and 595 child cyclists killed or seriously injured on the roads, and 11,643 and 4,769 respectively for all severities. Some people assume a 1:20 rule for fatal to serious to slight; assuming this rule to be true, and assuming that the balance is accounted for by under-reporting, the majority of adult injuries recorded in HASS/LASS would seem to be due to road cycling. Urban roads are the most common place for injuries to happen outside the home.

TRL 220, discussed below, puts the number of injuries (all severities) at around 100,000, as do RoSPA in a 1996 booklet (this is the source of the figure used by Lee &amp; Mann in their papers). Although these figures are speculative they are plausible - but remember that the vast majority of these injuries will be trivial.

The likely figure, then, would be:
 * 113 dead
 * 3000 serious traffic injuries, using Mills's 36% under-reporting for car v bike; 93% of recorded injuries on public roads &amp; footways
 * 100,000 trivial injuries, maybe.

Since over 3,000 children are admitted to hospital for cycling injuries of various sorts, and this exceeds the number of serious injuries recorded above, we might speculate that many of the admissions are not recorded as serious by the Police. For a more detailed picture, TRL220 is an excellent source.



How many children are injured cycling every year? 

Figures given to CTC by the Department of Health show just over 2,183 child cycling head injury admissions to hospital in 2002, 37.6% of all child cyclist admissions, of which under 500 are likely to have been genuinely serious injuries to parts of the head covered by a helmet.

Child cycling head injury admissions, then, account for 2.4% of child admissions, and 7.1% of child head injury admissions.

Injury risk is strongly age- and gender-dependent, with teenaged boys being most at risk. Walking alongside a road seems to be a major source of risk, and overall child pedestrian accidents are more likely to result in head injury than child cycling accidents, although when these are separated out it turns out that motor vehicle involvement is the big predictor of both occurrence and seriousness of head injury. In this respect cycling and walking are similar. There are around six times as many child pedestrian head injuries as child cyclist.



What is the relative risk? 

INRET (the French equivalent of TRL) studied 5459 casualties that were hospitalised after serious road crashes. The study noted the proportion of road users that suffered more than 24 hours' unconsciousness following the crash. The results were: The study was in the late 1980s, before people were wearing helmets in France. (Ramet M, Vallet G. Typologies des accidentes du trafic routier a partier de 5459 dossiers. Rapports INRET/LCB Aug 1987 p106)
 * pedestrians 4.2%
 * motorcyclists 3.9%
 * cyclists 2.3%
 * car occupants 1.3%.



So what is the risk per unit exposure? 

CTC has calculated that the risk of serious injury for its members equates to around one injury per three thousand years of regular cycling.

Another risk estimate from someone involved in transport planning in Oxfordshire: &quot;The number of accidents versus the number of opportunities is a big ratio. In Oxfordshire over a 5 year period there were around 1500 cycle accidents. In that same period one in ten of Oxfordshire's 600,000 population made roughly 2 cycle trips a day every day. Assuming a potential 1 reportable accident per trip, that's 219 million opportunities. So only 1 accident per 146 thousand chances of an accident. It is known that pedestrians from the poorest fifth of the population are 5 times more likely to be killed or injured than those from the wealthiest. Helmets may reduce the risk of injury in the event of a crash by 10% - 20%, but if those least likely to wear them are 5 times more likely to crash than those most likely, the reduction in total injuries is not going to be 10% - 20% but more like 1% - 2%. I don't think you'd notice the benefit in the noise.&quot;

The cyclist fatality rate in the UK per billion passenger km was 25.9, against an average for all modes of 12. Walking is rather more dangerous than cycling by this measure, but it is skewed by inaccuracies in the exposure measures.



Still confused! Is cycling dangerous? 

Not especially, and your chance of receiving a head injury should there be a crash is no different from any other mode - the thing that predicts head injury, especially serious head injury, is the involvement of motor traffic. The first, best thing you can do to reduce your chances of injury is to get trained. Adult cycle training is becoming much easier to find, and when the CTC staff and officers sampled the training recently they all came away having learned useful skills and tips.

If you can't find a training course - or if you can - you should also read Cyclecraft by John Franklin.

Helmets Work!
Yup, they definitely work. Up to a point. The $64 question is, of course, what point. Let us review some of the claims of efficacy:

So we can see that (a) the confidence intervals are very wide, not surprisingly given the small sample sizes, and (b) there are some evident differences in injury profile between the populations (unhelmeted cyclists are much more likely to suffer trunk injury, but much less likely to suffer face and neck injuries, which helmets don't prevent). The differential effect of helmets owned but not worn over those not owned at all is also puzzling!

In the Conclusions the authors state: &quot;However, the incidence of helmet wearing is low in Britain - 10.9% in our study. Educational programmes have been effective in increasing helmet use to over 50% in some American cities, and this has been accompanied by a 75% reduction in the number of bicycle related head injuries requiring hospital care (F Rivara, personal communication). The early results of our educational programmes in Cambridge are encouraging: there has been an overall increase in helmet use for the past two years, from 10% at the start of 1992 to over 16% in 1994&quot;

And during that period (1992-1994) when helmet use increased by 2/3 in Cambridge, what happened to reported head injury rates?

So once again the claimed benefit is not observed in the whole population. But the authors dispute this, citing a letter from Rivara (remember that name?). Look again at that claim: an increase to 50% helmet wearing has resulted in a 75% reduction in hospitalisations for head injuries. The reduction in injuries is much greater than the increase in helmet use!   Head injuries to bicyclists and the New Zealand bicycle helmet law, Scuffham P, Alsop J, Cryer C, Langley JD. 2000. Accident Analysis and Prevention: 2000 Jul;32(4):565-73  This conclusion was reached by taking a subset of data the author had used in a previous paper, and contradicts his earlier conclusion that &quot;increased helmet wearing percentages has had little association with serious head injuries to cyclists as a percentage of all serious injuries to cyclists [...] with no apparent difference between bicycle only and all cycle crashes&quot; ( Trends in cycle injury in New Zealand under voluntary helmet use, Scuffham PA, Langley JD. 1997. Accident Analysis and Prevention: 1997 Jan;29(1):1-9).
 * 19% of serious head injuries prevented

Problems with this paper include:
 * The HI rate in the first year considered was somewhat above the trend for the whole population, and the return to trend is the major source of the claimed benefit
 * Scalp lacerations are included as head injuries, although these are of little public concern and were not an area of focus in promoting the law

But these are minor points compared with what was found when Nigel Perry re-analysed the authors' own data, which they provided for him. The following chart was produced from that data, including data points not mentioned in the report, and shows the change in head injury rate for cyclists and for the whole population, and the change in helmet wearing rate over the same period:

From this it is obvious that: This is compelling evidence to support the idea that, whatever the efficacy of helmets themselves, helmet laws are not an effective way to reduce cyclist head injuries.   The effectiveness of bicycle helmets: a study of 1710 casualties, McDermott FT, Lane JC, Brazenore GA, Debney EA, Journal of Trauma: 1993; 34(6):834-845  From the Abstract: &quot;The efficacy of helmet use was evaluated by comparison of crashes and injuries (AIS-1985) in 366 helmeted (261 Australian Standard approved and 105 non-approved) and 1344 unhelmeted casualties treated from 1987 through 1989 at Melbourne and Geelong hospitals or dying before hospitalization. Head injury (HI) occurred in 21.1% of wearers of approved helmets and in 34.8% of non-wearers (p &lt; 0.001). The AIS scores were decreased for wearers of approved helmets (p &lt; 0.001), face injuries were reduced (p &lt; 0.01), and extremity/pelvic girdle injuries increased (p &lt; 0.001) and the overall risk of HI was reduced by at least 39% and face injury by 28%. When casualties with dislodged helmets were excluded, HI was reduced 45% by approved helmets. Head injury reduction by helmets, although substantial, was less than that found in a similar study in Seattle, Washington.&quot;
 * The general fall in the likelihood of head injury for cyclists coincides to a high degree with a similar fall in head injury for non-cyclists (who make up the great majority of the whole population control group).
 * There is a fall for cyclists and not the control group when the law was introduced, but the cyclist head injury rate had previously risen above the overall one, and the fall is soon followed by an increase. The cyclist head injury rate does appear to fluctuate a little more than the overall rate (probably due to small numbers).
 * There has been no additional benefit for cyclists through the wearing of helmets that has not been enjoyed by the population as a whole without helmets. This is despite the fact that the survey on which the graph is based included head injuries sustained in simple falls (for which cycle helmets are designed to offer some degree of protection) as well as more serious instances of collisions with motor vehicles.
 * 39% of head injuries
 * 28% of face injuries

Note that there is no comment on the relative severity, or whether or not a motor vehicle was involved. The claim regarding facial injuries may indicate confounding factors. Comments like: &quot;Wearers of non-approved helmets sustained a blow to the head, face, or helmet more frequently (66.0%) than wearers of approved helmets (50.6%) or unhelmeted casualties (53.4%)&quot; also suggest differences between the populations under consideration.

The claimed benefit is under half that of the Seattle study, and the sample group is much larger, in keeping with the common trend that larger studies produce lower figures. <td width="25%"> <td width="25%"> Pedal cycle accidents – a hospital based study, Paula Mills, TRL research report 220, 1989 <td width="75%"> These claims are noticeably lower than those usually made by helmet proponents. The study provides a lot of useful data, including nailing the idea that there is any significant under-reporting of fatal cyclist injuries as claimed by BHIT. The calculated under-reporting rates for slight, serious and fatal injuries are 74%, 61% and 0% respectively, with under-reporting of serious road injuries probably lower (36% in the case of car v bike injuries). From this we can extrapolate the DfT road casualty data to show something like a 20:1 ratio between slight and serious, and between serious and fatal injuries. The numbers of fatal injuries are extremely reliable, so this may be a helpful rule of thumb for checking claims of serious and slight injuries.
 * 30% of slightly injured would be uninjured
 * 18% of the serious casualties would be slight
 * 11% of serious casualties would be uninjured

The locations of injuries as recorded were: It also provides the following table for fault in bike v car crashes: Fault was more likely to be assigned to younger cyclists.

Less than 5 per cent of the cyclists who had their accidents on a road or cycle track had been wearing conspicuity aids, however forty-two per cent of the cyclists had at least one conspicuity aid, not including rear reflectors, fitted to their bicycles, and lack of conspicuity was considered a factor in around 20% of cases.

The incidents giving rise to injury in adults were:

Note that this is for all crashes, including off-road. Clearly the major source of danger is the classic SMIDSY.

Unfortunately despite the wealth of data the report provides, there is insufficient detail to assess the reliability of the claims regarding potential injury savings. This is not a surprise, since the main thrust of the document is not to investigate helmet efficacy but to quantify the number and sources of injury, and in particular to establish the levels of under-reporting.

<td width="25%">

<td width="25%">

Age profile <td width="75%">

Both helmet efficacy and accident involvement appear to be strongly age-dependent. It appears that the greatest benefit is experienced by the youngest children, but the highest number of accidents is experienced by teenaged boys. Again, it would be a mistake to suggest that the differential efficacy between younger and older children is a function of the helmets themselves - older children have more fully-formed skulls, and of course they are bigger and stronger. Teenaged boys are an injury risk just sitting still - and you know what happens when they get into a car!

There is definite merit in encouraging young children when learning to ride to wear something on their head - as well as knee pads and elbow pads.

So, helmets probably work. For certain given values of &quot;work&quot;. They are good for protecting against minor knocks, and very bad at protecting against serious injury, especially from motor traffic. Which invites the question why helmet laws are always sold on fatality statistics, which are dominated by road traffic crashes...

Helmets Don't Work!
For sure, helmets definitely don't work. For certain given values of &quot;work&quot; of course...

Two Old Women
Long and terrible arguments have raged between road and off-road cyclists, often both opposed to compulsion but with a completely different perspective on what constitutes &quot;reasonable precautions&quot;. Like the two old women holding a slanging match between upper windows on opposite sides of a cobbled street, they are arguing from different premises. This is eloquently summed up here: &quot;There is no evidence [...] that helmets have had a marked safety benefit at the population level for road-using pedal cyclists. Clearly this cannot be extrapolated to non road-using pedal cyclists, indeed it may well be that leisure cycle use is unusually well protected by helmet wearing. Health practitioners, who have additional concerns about leisure use of bicycles may have justified interest in cycle helmets across the whole spectrum of cycling activity. However, it would appear that helmet wearing has at best a modest role in terms of Transport policy. Transportation practitioners therefore need to concentrate on primary safety, to prevent collisions occurring. Whilst it may be desirable for individuals to wear helmets, the circumstances when helmets may be effective are not clear. In particular, the evidence that cycle helmets are effective in traffic collisions is much weaker.&quot; ( Cycle Helmets and Simpson's Paradox: where are the casualty savings? Hewson PJ, 2004)

This also goes to the heart of the disparity between observational studies and population and time trend statistics. It is not alone in identifying fundamental differences between the helmeted and unhelmeted populations: &quot;Discounting direct head injuries, helmet use has been associated with a much lower incidence of severe injury (injury severity score &gt;15) to the whole body.17 It has been suggested that non-use is a marker of a population of cyclists more likely to be involved in high impact crashes with motor vehicles, perhaps as a result of less safe cycling practices. This study supports the view that use of a cycling helmet is associated with higher use of pre-event phase equipment measures to avoid collision.&quot; ( Cycling safety: injury prevention in Oxford cyclists, L McGuire, N Smith, Injury Prevention 2000;6:285–287).

&quot;Helmet non-use was strongly associated with severe injuries in this study population. This was true even when the patients without major head injuries were analyzed as a group; a finding not previously described to our knowledge. This implies that helmet non-users tend to be in higher impact collisions than helmet users since the injuries suffered in body areas other than the head also tended to be much more severe. Helmet use may be a &quot;marker&quot; for a population of cyclists who tend to be in less severe crashes. It is possible that some of the &quot;protection&quot; against head injury ascribed to helmets

in previous studies is actually a reflection of the severity of the impact sustained by helmet users compared with that sustained by non-users.&quot; ( A prospective analysis of injury severity among helmeted and non helmeted bicyclists involved in collisions with motor vehicles, Spaite DW, Murphy M, Criss EA, Valenzuela TD, Meislin HW. 1991. Journal of Trauma: 1991 Nov;31(11):1510-6).

Logical Fallacies
Logical fallacies abound in the helmet debate, and can be seen from those on both sides of the argument - and even those in the middle. Logical fallacies are actually a common feature of all debate, and the more heated it becomes, the more entrenched the positions adopted, the greater the likelihood of their coming up. There are some good sites on the web regarding logical fallacies and how to recognise them. <a href="http://www.nizkor.org/features/fallacies/" target="_blank">Nizkor</a> is good, and so is <a href="http://www.datanation.com/fallacies/" target="_blank">Stephen Downes'</a> guide to the logical fallacies. To a large extent they rely on a common fundamental flaw: the confusing of rationalisation with reasoning.

Logical fallacies will also creep in when the writer is looking to inject certainty. The helmet issue is fraught with contradictions and any truly authoritative statement is likely to require precision of wording, or many caveats. Usenet is a forum well suited to lengthy discourse, but (to show my prejudices) web forums tend to attract readers with less appetite for detailed argument, and a greater tendency to try for soundbytes. Soundbytes, in helmet wars, are almost invariably fallacious - in my view, anyway.

I have <a href="logical_fallacies">a whole page on logical fallacies</a> - see how many you can spot. Bonus points for catching me out.

Compulsion
Here are two arguments taken from Target Risk by Wilde:
 * 1) All human beings are mortal
 * 2) Socrates is a human being
 * 3) Therefore, Socrates is mortal

and


 * 1) A river empties into the sea through a delta
 * 2) The delta has three channels, all of equal size
 * 3) Therefore, damming two of the channels will reduce the flow of water to the sea by two-thirds.

One of these is self-evidently true, the other clearly wrong. So here is another statement:
 * 1) Cyclists can suffer head injury in a crash
 * 2) Helmets reduce head injury in the event of a crash
 * 3) Therefore cyclists should wear helmets

This is clearly analogous to one of the two statements above. But which one? Wilde's comment on the second statement is this: &quot;One cannot stem the flow as long as there remain alternative routes to the destination. One cannot reduce mortality due to accidents and lifestyle-dependent disease unless all opportunity for premature death were eliminated by law or made impossible through technological intervention. And that, of course, can never be fully achieved. In the case above, the river would simply develop a fourth channel.&quot;

This is, of course, not a precise analogy. But it is a fair point. And especially when you consider that risk is not a measurable absolute, but a cultural construct, and one which varies from person to person. One person will be happy to go bungee jumping and skydiving, another will ferry Tarquin and Jocasta to school in the Range-Rover to avoid the danger posed by - well, by people ferrying Tarquin and Jocasta to school in the Range-Rover. Risk aversion varies with social class, gender and age. Middle-aged, middle-class women are very risk averse, teenaged boys from poorer social backgrounds are the least risk-averse. This is hardly a big secret. And the reason that helmet laws fail to live up to expectations may well be that they are trying to coerce people into someone else's pattern of risk-taking.

And there is no possible doubt that laws have failed to deliver anything close to the claimed levels of injury reduction. Far from preventing 85% / 75% / 69% / 65% / insert random percentage here of injuries, actually they don't even prevent enough injuries to pay for all the helmets in reduced healthcare costs. And even that is not actually a surprise - cycle injuries are rare, and you have to buy an enormous number of helmets to prevent any significant number of injuries.

Have a look at percentage head injury versus helmet wearing rates for Western Australia and New Zealand, probably the two most closely studied helmet law jurisdictions:

The NZ chart does not show the figures for the whole population - these follow pretty much the adult trend. Reductions in head injuries seem to follow enforcement of traffic laws, and modal shifts away from road cycling. This is obvious, since cars are the major source of serious head injury.

So: helmet laws fail for a number of reasons, including:
 * they are sold on traffic danger, but helmets are not designed for traffic crashes
 * they are sold with grossly exaggerated efficacy figures
 * cycle injuries are rare so enormous numbers of helmets are required to yield measurable reductions in injuries
 * aggressively enforced laws deter cycling and reduce &quot;safety in numbers&quot; benefits
 * risk-averse cyclists are already wearing helmets, and the rest may risk compensate away any benefit.

Abuse@
Now we come to the vexed issue of helmet wars. Helmet threads are inevitable, the consequence of a clash of deeply held beliefs. They are also - contrary to what many might think - productive, at least on uk.rec.cycling. It has been suggested that nobody changes their mind as a result of a helmet war, but actually that is not true, a lot of us started as strongly pro-helmet and have had our eyes opened by the presentation of evidence which - let's be honest - helmet proponents don't so much as address, as sweep under the carpet. It often comes as a shock to people, even experienced cyclists, to find that there is any evidence at all to contradict the 85% figure they've been presented with for over a decade.

They are productive up to a point, the point where a helmet thread becomes a helmet war. At this point positions have been taken, trenches dug, and anybody going &quot;over the top&quot; is likely to come under heavy fire from the opposite side. The debate tends to become robust (read: seriously bad tempered). It is only a matter of time before someone posts one of the classic Liddite throwaways:

For some reason those who post these arguments seem to get upset when the response is widespread withering scorn. Who could have predicted that? That is such an atypical reaction to the assertion that one person has the monopoly on truth!

Here is a point to ponder: the people putting the sceptical viewpoint have often read dozens, sometimes hundreds, of helmet papers. Those arguing the points above usually turn out not to have read any, beyond the carefully-edited abstracts recycled by pro-helmet campaigners. Hmmmm.

Shoot the Messenger
One reason why I am suspicious of pro-helmet arguments (and I know others share this) is that the most vociferous proponents of helmets tend not to be too scrupulous. In the UK, the leading pro-helmet group is BHIT. They have been responsible for a number of dodgy claims, which I detail in this table.

In a bizarre twist on the <a href="asa_complaint">ASA complaint ruling</a>, BHIT complained to ASA about a briefing document for MPs which contained a section much like the above headed &quot;myths&quot; and &quot;facts&quot;. ASA decided that the Parliamentary briefing was a marketing communication (selling what?) and ruled that although the myths were indeed false claims made by the helmet lobby, and the facts were indeed accurate, because there was dispute about the extent to which the (acknowledged true) facts rebutted the (acknowledged false) claims, this was misleading. Er, right.

BHIT derives much of its income from grants form the Department of Health and Department for Transport - that's you and me. Thus far what they have delivered in return for around £100,000 of public money is a couple of reports claiming that helmet promotion can increase helmet use (really? who would have thought it?) but containing too little data to evaluate the other claims contained, a conspicuously inaccurate Early Day Motion, and campaigning for a helmet law. These political campaigning activities must be done out of their unrestricted funds, but much of their income (e.g. Government grants) is restricted.

BHIT have also engaged in some seriously distasteful emotive campaigning. When Troy Parker was killed riding off the pavement into the path of a car on a bike with defective brakes, they brought his grieving mother to Westminster to press the case for a helmet law. Leaving aside for a moment the fact that there is no proof a helmet would have saved his life, as the Coroner said, it was riding on the footway and having defective brakes which caused the crash. And they have a video about a boy who is reduced to a vegetable after crashing his birthday present bike (unhelmeted). Curnow shows that this kind of brain injury is most likely to be caused by a type of force against which helmets provide no protection, and could even exacerbate. But BHIT make no claims to be a cycle safety charity - their sole interest is in promoting helmets.

In short: the Government is paying them a lot of our money to provide expert information on cycle helmets. They do not do this. They are propagandists. In addition to the dodgy claims above, they also quote, uncritically, the 85% figure - even after accepting to the ASA that they should not make such claims.

In the USA helmets are strongly promoted by the National SafeKids Campaign. Would you be surprised to learn that they are sponsored by Bell? Probably not. Especially when you hear about recent moves in the USA towards helmets for soccer... Guess what figure they quote in their helmet promotion campaign? Yup, 85%.

Which invites the question: if helmets are such a good idea, why is it necessary to lie in order to promote them? I'll leave you to ponder that one at your leisure.

Can we stop now?
Right, so now you can quote at least three studies to support your pre-existing point of view, whatever that might have been. So how has that helped, exactly?

It has helped in this way: And now you are ready, Grasshopper, for the Great Truth: When cycle safety interventions are rationally ranked by likely effectiveness, helmets are always placed last. The reason is simple and obvious. It is risk management 101: first reduce risk at source, then reduce exposure to risk, and only when this fails apply personal protective equipment.
 * you are better informed
 * you understand that there is no simple answer to the question of whether helmet use is good or not
 * you realise that simplistic arguments - on either side - are almost invariably incomplete, usually to the point of uselessness.</ul>

CS Downing's &quot;Pedal Cycle Accidents in Great Britain&quot; (TRRL, 1985) rated the efficacy of interventions in reducing cyclist casualties thus:

Note that this was before helmets really started to take off, and risk-averse cyclists had just started to wear hard shell helmets.

The fundamental flaw with helmet promotion is that it ignores this principle, and elevates cycle helmets - a palliative measure, and one designed only for a small subset of the accidents which cause serious injury - to first place. In fact, only place. Helmet lockers are marketed as a &quot;cycle safety programme&quot;; helmets &quot;help children cycle safely&quot; But this is arrant nonsense! Cycle safety is not about planning for when you hit the ground, still less about making it less unpleasant to do so - it's about not hitting the ground in the first place!

So you can join the urc regulars in singing our variation on the Blue Öyster Cult classic:

You see me now, a veteran

Of a thousand helmet wars

I've been living on the edge so long

Where the winds of limbo roar

And I'm young enough to look at

And far too old to see

All the scars are on the inside

I'm not sure that there's anything left of me