Martlew Letter Guardian

Sir, MP proposes to fine children who cycle without helmets (Guardian, 8 Jan, 2004) I apologise if by now you have had rather a lot of emails on this subject and are weary of it. To those of us who cycle it is an important matter.

The idea of helmet compulsion is seductive as a way of "fixing" the danger posed by cars to children without actually tackling the danger, which would be politically inexpedient. Unfortunately the idea is built on logical fallacies and flawed research. It has been tried in other countries, and the result has been massive reductions in numbers cycling and increases in cyclist injury rates. Mr Martlew's bill is wrong on a number of counts: First, nine out of ten child cycle accidents happen in off-road play. Unless Mr Martlew proposes to force use of helmets by children on private land, this will not be addressed. The undesirability of regulating what we wear on private property should not need to be spelled out. Second, there is no proof that helmets make the difference between fatal and non-fatal crashes - or indeed that they prevent anything other than superficial injuries. Helmet advocates seek to conflate head injuries (which include cuts and abrasions to parts of the head not covered by a helmet) with serious or life-threatening head injuries. This is a logical fallacy. Not only are most of these injuries trivial, but in sixteen out of nineteen cases recently reviewed, cyclists whose cause of death was recorded as head injury were found to have other mortal injuries as well. Third, even if all child cyclist fatalities could be prevented through helmet use (which even advocates do not claim), the effect would still barely scratch the surface of the much deeper problem of traffic danger to children. Road traffic crashes are the leading cause of death in school-age children in the UK today, and most of those children are not rising bicycles at the time. Fourth, you are more likely to suffer a head injury while driving or walking than while cycling. Forcing helmets on cyclists in isolation makes no sense. Fifth, inactivity is a greater danger to childrens' health than cycling-related head injuries. Every country where helmet compulsion has been tried has seen a substantial and sustained drop in numbers cycling. Cycling is sufficiently safe that the BMA reckons the benefits outweigh the dangers by around 20:1 - focusing on the small danger and ignoring the large benefit is especially short-sighted at a time when children are being diagnosed with Type II (obesity-related) diabetes. Sixth, aggressive promotion of cycle helmets carries the very real risk that those wearing them will overestimate their protective effect. This idea of risk compensation is repudiated by helmet advocates but they have not yet advanced any alternative explanation for the observed fact that injury rates typically rise when compulsion is introduced.

Beware the anecdote. It is easy to assume that every cyclist who dies while not wearing a helmet would have survived had they wore one. This is simply unsupportable. Indeed, in two incidents I know of, experienced riders in their early seventies were pitched over the bars on hitting a pothole (a very rare but dangerous type of crash). One died, the other survived. The one who died was the one wearing a helmet, the survivor wore only a cotton cycling cap. Equally, those who survive crashes while wearing helmets always attribute their survival to the helmet, but this too is wrong. The human skull is a tough customer. While recognising that immature skulls are less strong than adult ones, it is nonetheless foolish to suppose that the helmet is the only thing between a falling cyclist and death or brain injury. The majority of falls from cycles end in nothing more serious than cuts and abrasions, generally not even affecting the head. The injuries which most concern us, those where a motor vehicle is involved, are outside the design envelope of cycle helmets as we know them. Helmets may make a marginal difference in some crashes, protecting reasonably well against cuts and abrasions but bringing an increased risk of some rare injuries due to increased size and mass of the head. One thing which helmets do nothing to prevent is the type of twisting injury known as Diffuse Axonal Injury (DAI). This is considered the leading traumatic cause of permanent intellectual disablement. There is even some evidence that helmets make this more likely, but that is controversial.

Finally, I have to ask why it is, if compulsion advocates have such a strong case, that they feel the need to exaggerate. This includes the use of a figure for helmet efficacy which was produced in only one study, and was corrected by its authors in 1996; claims for child cyclist head injury numbers which exceed the total numbers of all cyclists injured with any severity; claims for potential savings to the NHS which are a third greater than the total NHS spend on children aged 4-16. Not everybody is so hysterical, though. Some studies are sober, peer-reviewed and place the risks in proportion. The best estimate I have seen form such studies is that compulsory helmet wearing for children might, if the numbers cycling remains unchanged, save two lives a year. Is it worth risking a one-third reduction in child cycling for this? Those two lives are a tragedy, but place them in context alongside the three thousand plus non-cyclists killed on the UK's roads last year and it seems that maybe we are solving the wrong problem. If you want to "think of the children" you will have far more effect by driving carefully than by forcing them to wear plastic hats.