Do helmets save lives?
Ed Walker says there is no evidence that cyclists are safer in head-gear
Guardian Tuesday June 15, 1999
As an Accident and Emergency doctor, I see lots of people who have fallen
off their bicycles, although the most seriously injured tend to get knocked
off by motorists. "And was she wearing a cycle helmet?" is a standard
question put to the parent of any injured child. Cycle helmets prevent
injuries and save lives. That's what we are all told.
But there's always a niggling doubt in my mind, and those of many other
doctors, that bike helmets aren't really all they are cracked up to be.
Why? Take these two examples: a six-year-old who slides off his bike on the
driveway, and suffers nasty grazes and bumps to the head, entirely
preventable had he been wearing a helmet; and a man of 40 flung from his
bike into the path of a lorry by a passing car - he's dead from massive
"non-survivable" head injuries. Even the best-designed bike helmet would
have made no difference.
It's nice to think that between these two extremes there must be cases where
helmets would make a significant difference to the incidence of long-term
disability or death. Nice, but probably incorrect.
The BMA's board of education and science, which has examined the evidence,
has just concluded that helmet use should not be compulsory in the UK. It is
estimated that only around 18% of British cyclists wear them. In Australia,
the home of helmet regulation, their use is mandatory. Deaths and serious
head injuries among cyclists in Victoria fell by around 45% in the year
following legislation in 1990. But so did the number of people riding bikes
- by 40% in adults and 60% in children. Is this the real reason for the
apparent drop in injuries and deaths?
Opponents of legislation point to New Zealand, where a sharp rise in
voluntary helmet use in the months prior to a new law being enforced was not
matched by any reduction in the rate of serious head injuries.
The Snell Memorial Institute in California was set up in memory of an
amateur motor racer who died in 1956 when his "state-of-the-art" helmet
failed completely to protect him. A Snell certification label is the gold
standard in terms of safety certification of protective headgear (Snell B95
is the one to look for when buying a cycle helmet.) But the institute has
never advocated any specific cycle helmet law.
Dr. George Snively, a founder, has said "it is impossible to build a [cycle]
helmet that will offer significant impact protection".
A live brain is said to have the consistency of blancmange. Putting
blancmange in a polystyrene box will not allow you safely to throw it
against concrete without the contents being just as badly shaken as had the
"protection" not been present.
"Bike helmet saved my life" makes a headline. But such claims often follow
off-the-cuff comments by doctors like me. Few of us who attend people with
cycle injuries are likely to be experts on the mechanics of impact injury.
Hundreds of people fall from bikes every day while not wearing helmets, and
avoid serious injury. These cases go unreported.
Campaigners for helmet laws approach the issue of cycle safety from the
wrong direction, because two thirds of the most serious bike accidents are
caused by car-drivers. This is certainly our experience in A&E departments,
and something the BMA report also acknowledged. It calls for legislation
aimed at drivers rather than cyclists; in particular, increased use of 20
mph speed limits in urban areas (although even at 20mph, and even if wearing
a helmet, a direct impact to the head is likely to be fatal.)
Pedestrians and car occupants are in fact more likely to suffer head
injuries from road accidents than cyclists. In the US, 34% of fatal head
injuries happen to people in cars. Some 7% are pedestrians, and only 1%
cycle riders. Yet no-one seriously suggests that helmets are worn by anyone
other than cyclists and motorcyclists.
Cycling is good for you - as long as you don't get knocked off. Forcing
people to wear helmets demonstrably reduces the number willing to ride a
bicycle. Less cycle use means more obesity, heart attacks, and use of other,
less environmentally-friendly means of transport. Making helmet use
compulsory gives cycling an undeservedly dangerous profile, and may
discourage bicycle use even further. Rather than encasing cyclists in
armour-plating, we should be directing our attention to that nut behind the
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