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-   -   Head Injuries. Am I right, or have I suffered a few too many (http://www.cyclebanter.com/showthread.php?t=57383)

Mark Thompson April 24th 04 10:25 PM

Head Injuries. Am I right, or have I suffered a few too many
 
While reading through The Effectiveness of Bicycle Helmets:A Review[1] in
section 2.3 paragraph 3, it quotes a study by Piggott et al, 1994[2] as
saying that

"The prevalence of head injuries among hospital admissions was 32 per
cent .... although for only 5 per cent was the head injury categorised as
being more than minor"

Sorry, what was that again?

"for only 5 per cent was the head injury categorised as being more than
minor"

So unless my brain is failing me again[3], and if this study is right and
the results are comparable across all hospitals:

1. 95% of the head injuries in hospital admissions in this study are
minor.
2. With plenty of exceptions, it is a broad rule that the harder the
impact, the more the damage.
3. Helmets protect better against impacts of a smaller force than of a
larger force.
4. So if x% of head injuries are prevented by wearing a helmet, then that
will generally be the least serious x%
5. So to start preventing significant amounts of serious head injuries
cycle helmets would have to reduce head injuries by more than 95% - and
that's just the ones serious enough to make people pop into the hospital!

I have two questions.

A) Is there a flaw in my logic?
B) Is the 5% figure valid for UK hospitals?



[1]
Revised Edition Prepared by Dr. Michael Henderson
for the Motor Accidents Authority of New South Wales, Australia.
1995
http://www.helmets.org/henderso.htm

[2]
Piggott P, Knuiman M W and Rosman D L, Rates and pattern of injuries from
bicycle crashes based on population: police and hospital data, Rood and
Transport Research, 3:64-74, 1994.

[3]
Postage and packaging free...

Just zis Guy, you know? April 24th 04 10:57 PM

Head Injuries. Am I right, or have I suffered a few too many
 
On 24 Apr 2004 21:25:33 GMT, Mark Thompson
wrote in message
57:

A) Is there a flaw in my logic?


No, there is a large heap of flaws in Henderson's ;-)

B) Is the 5% figure valid for UK hospitals?


90,210 admissions
5,804 cyclist admissions
2,183 cyclist head injury admissions
Under 400 known serious cycling head injuries
Unknown number of the above to areas covered by the helmet, studies
suggest around half.

According to the Government's figures around one in ten of these
serious injuries might be preventable by a helmet.

I wonder what the injury reductions in Hull's home zones have been
like?

--
Guy
===
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington University

Simon Mason April 25th 04 03:40 PM

Head Injuries. Am I right, or have I suffered a few too many
 

"Just zis Guy, you know?" wrote in message
...


I wonder what the injury reductions in Hull's home zones have been
like?


I don't think they break down the figures for individual homezones, all I
know is that since the 20 mph limits were introduced to now 25% of the city,
injuries to cyclist and peds are at an all time low. This piece was from
last November 03.

http://www.thisishull.co.uk/displayN...tentPK=7675956

If Proof was ever needed about the effectiveness of Hull's 20mph zones, it
has finally been delivered.

New statistics reveal 300 accidents involving children have been prevented
since the lower speed limits were introduced eight years ago in residential
areas.

But the £4m success story making our roads safer doesn't end there.

Hull now leads the country in its pioneering work cutting speed limits.

The city now boasts more 20mph zones than any other local authority, with
more than one quarter of Hull now covered.

Such progress has quite rightly earned praise from the Government's Health
Development Agency.

However, it is vital the work on road safety does not end there.

Areas which do not already benefit from 20mph limits need to be included as
soon as possible.

It is crucial police continue to make the resources available to enforce the
restrictions.

And it is also vital innovative new ways are found to make accident-prone
roads more pedestrian-friendly.

If motorists feel they are being unfairly victimised, then they should think
again.

Up to 13,000 children could be saved from death or serious injury each year
if speed limits on all residential roads nationwide were cut to 20mph.

It is a small price to pay if slowing down helps save a child's life.

--
Simon M.




Alan Braggins April 26th 04 11:37 AM

Head Injuries. Am I right, or have I suffered a few too many
 
Mark Thompson wrote:
3. Helmets protect better against impacts of a smaller force than of a
larger force.
4. So if x% of head injuries are prevented by wearing a helmet, then that
will generally be the least serious x%
5. So to start preventing significant amounts of serious head injuries
cycle helmets would have to reduce head injuries by more than 95% - and
that's just the ones serious enough to make people pop into the hospital!

I have two questions.

A) Is there a flaw in my logic?


Helmets could plausibly prevent (i.e. make non-injuries) only 5% of
injuries and still reduce some serious injuries to not-serious.
You only have to prevent over 95% of injuries to make some of the
serious injuries into non-injuries.

Now other figures suggest that helmets don't actually provide that
benefit, or only to a very small extent, but I don't think the argument
above is enough to show that, at least without some elaboration of 4.
(And if that elaboration turns into "helmets are, on the whole, useless
in serious impacts", you can omit the other steps.)

Simon Brooke April 27th 04 09:05 AM

Head Injuries. Am I right, or have I suffered a few too many
 
in message , Alan Braggins
') wrote:

Now other figures suggest that helmets don't actually provide that
benefit, or only to a very small extent, but I don't think the
argument above is enough to show that, at least without some
elaboration of 4. (And if that elaboration turns into "helmets are, on
the whole, useless in serious impacts", you can omit the other steps.)


It may be worse than that. It may well be 'helmets mitigate injury in
minor impacts but agravate injury in [some|many|most|all] major
impacts'. Someone with serious research funding needs to do a study on
the rotational acceleration effects of glancing blows on helmets. It
may be that on investigation this turns out to be not serious and not
likely to cause severe injury - and it may not. It urgently needs
serious investigation.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; I'd rather live in sybar-space


Mark Thompson April 27th 04 09:38 AM

Head Injuries. Am I right, or have I suffered a few too many
 

minor impacts but agravate injury in [some|many|most|all] major
impacts'.


The only reports on it I've seen said it was likely to happen in only a
very few cases.

It also said that a major impact was not needed for injury to occur, as
even minor impacts could cause the effect (but presumably were less likely
to injure).

On the other hand, it also said that serious brain damage/death only
hapened in a very few cases.

But it went on to say that as rotational thingummies are more likely to
cause severe brain damage/death, then it's likely to be over-represented in
the more serious cases.

So yeah, more research needed!


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