Definitive proof ;-)

[email hidden] wrote on 19/03/2007 12:54 +0100:

Quoted message said:

I am quite happy for people not to wear helemts. Its really up to
them. Having attended so many cycle accedidents as a medic, I can see
first hand the difference between wearing one or not. Seeing head
injurys on cyclists on a daily basis, I know wearing a helmet doesn'
stop head injury, but the 'dampening' effect it has is often the
difference between recovery and perminant injury.

As a good friend of mine says, the plural of anecdote is not data. I
may be old school but I prefer my medical advice to be evidence, not
anecdote, based.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

Ian Smith said:

Ziggy said:

The fact that helmets are oversold does not mean they are never a
lifesaver.

Which is true.

But no more true than that it's possible for a lucky rabbit's foot to
save your life.

I can't really agree with that.

Only under truly bizarre circumstances could a rabbit's foot save your life.

On the other hand, there must be a number of cases worldwide each year, however
small, where a cyclist dies of a head injury where the impact was just hard
enough to be fatal and where even a small layer of foam would have decreased the
effect of the impact at the skull sufficiently to save the cyclists life.

Tony Raven said:

[email hidden] wrote on 19/03/2007 12:54 +0100:

Quoted message said:

I am quite happy for people not to wear helemts. Its really up to
them. Having attended so many cycle accedidents as a medic, I can see
first hand the difference between wearing one or not. Seeing head
injurys on cyclists on a daily basis, I know wearing a helmet doesn'
stop head injury, but the 'dampening' effect it has is often the
difference between recovery and perminant injury.

As a good friend of mine says, the plural of anecdote is not data. I
may be old school but I prefer my medical advice to be evidence, not
anecdote, based.

Evidence is, that if you bang something rigid(ish) (such as a skull) against
something solid (such as a kerbstone), it takes a greater force to damage it if
you intersperse something that will deform on impact between the two
experimental objects.

It therefore seems likely that helmets will prevent some number of head injuries
each year and reduce the seriousness of some other number.

Of course, both numbers might be quite small but I doubt that they are actually
zero.

Ziggy wrote on 19/03/2007 14:17 +0100:

Quoted message said:

Evidence is, that if you bang something rigid(ish) (such as a skull)
against something solid (such as a kerbstone), it takes a greater
force to damage it if you intersperse something that will deform on
impact between the two experimental objects.

It therefore seems likely that helmets will prevent some number of
head injuries each year and reduce the seriousness of some other
number.

Of course, both numbers might be quite small but I doubt that they
are actually zero.

Save us all a lot of trouble and go and Google the group and read up at
http://www.cyclehelmets.org. We've done all this to death many times
before and the simple summary is you are wrong for a whole load of
reasons I won't go into again in deference to the sanity of the rest of
the group.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

"Ziggy" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

I'm guessing your 'medical training' didn't involve much in the way
of 'statistics and stuff' and this is why you'd rather rely on meaningless
anecdotal evidence instead.

The 'statistics and stuff', on both sides of the debate, are pretty
meaningless
because of the impossibility of doing like for like studies over
meaningful
populations.

Um - it's been done. See eg the stats for where there was a significant step
change in helmet wearing.

Quoted message said:

So we have to fall back to simple physics.

Inasmuch as any problem can be reduced to simple physics, maybe. But it's
more conventional and manageable to use the sciences more appropriate to the
problem - and even then it's pretty tricky, since psychology appears to play
an important part in determining the benefit or otherwise provided by
helmets.

Quoted message said:

Any structure will, upon impact, be affected to a degree determined by the
accelerative force on that structure.

Anything that decreases that accellerative force will reduce the potential
damage.

If you don't believe me, try banging your head firmly against a brick wall
faced
with a polystyrene ceiling tile and then against an unfaced brick wall.
Come
back and report your findings 😉

Very good. Now try extending your model to something more like real life.
Yours is a common mistake - the disappointing thing is that it's still being
made.

How does your model cope with at a bare minimum :

Helmet size making impacts more likely
Helmet weight making impacts more likely
Percieved safety of helmet leading to more risk taking and hence higher
probability of impact
Other road users perceptions of helmet wearers altering impact probability

?

All of these happen. Unfortunately it does mean the problem is rather more
complicated than you'd like. In fact, it means it's sufficiently complicated
that we have to resort to "statistics and stuff" to get a better measure of
the effectiveness of helmets.

clive

Ziggy said:

Evidence is, that if you bang something rigid(ish) (such as a
skull) against something solid (such as a kerbstone), it takes a
greater force to damage it if you intersperse something that will
deform on impact between the two experimental objects.

Absolutely. If all you care about is damage to your skull, I agree
that wearing a helmet makes a lot of sense.

Personally, I care more about my brain than my skull.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

Ziggy said:

Ian Smith said:

Ziggy said:

The fact that helmets are oversold does not mean they are never a
lifesaver.

Which is true.

But no more true than that it's possible for a lucky rabbit's foot to
save your life.

I can't really agree with that.

Only under truly bizarre circumstances could a rabbit's foot save your life.

Eh? You can't agree that it's possible for a rabbit's foot to save
your life, then in the very next sentence you agree that in certain
circumstances it could.

When you've decided what you agree with, can you let me know.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

On Mon, 19 Mar 2007 14:17:30 GMT

(Ziggy) said:

Evidence is, that if you bang something rigid(ish) (such as a skull)
against something solid (such as a kerbstone),

I don't do that.

But the last two times I've gone over the handlebars, I'd have been
very unlikely to escape such an impact if my head had been encumbered
by some hulking great shell.

Quoted message said:

It therefore seems likely that helmets will prevent some number of
head injuries each year and reduce the seriousness of some other
number.

And be the cause of some further number. Statistics say this third
number is the highest.

--
not me guv

Ziggy said:

The 'statistics and stuff', on both sides of the debate, are pretty
meaningless because of the impossibility of doing like for like studies
over meaningful populations.

So we have to fall back to simple physics.

The statistics are difficult to interpret: I agree.

We have to fall back to naive oversimplified physics: I disagree.

Quoted message said:

If you don't believe me, try banging your head firmly against a brick wall
faced with a polystyrene ceiling tile and then against an unfaced brick
wall. Come back and report your findings 😉

If you think you're advancing the whole helmet debate here, you're very much
mistaken.

Anthony

In article <[email hidden]>, Ziggy
[email hidden] says...

Quoted message said:

So if you had the choice of a fractured skull or a fractured femur, which would
you choose? ;-)

Skull - I've done the femur thing several times and I'm bored of it.

Ian Smith said:

Ziggy said:

Ian Smith said:

On Mon, 19 Mar 2007 13:07:19 GMT, Ziggy <[email hidden]> wrote:

> The fact that helmets are oversold does not mean they are never a
> lifesaver.

Which is true.

But no more true than that it's possible for a lucky rabbit's foot to
save your life.

I can't really agree with that.

Only under truly bizarre circumstances could a rabbit's foot save your life.

Eh? You can't agree that it's possible for a rabbit's foot to save
your life, then in the very next sentence you agree that in certain
circumstances it could.

No.

Read what you wrote, and what I said. There is no inconsistency.

Quoted message said:

When you've decided what you agree with, can you let me know.

I knew from the outset what I did and didn't agree with 😉

On Mon, 19 Mar 2007 14:27:26 -0000, "Clive George" <[email hidden]>
wrote:

Some stuff.

You seem to be labouring under the misapprehension that I'm arguing that helmet
wearing is a 'good thing'.

I'm not.

I'm just pointing out that there are almost certain to be circumstances when
wearing a helmet saved someone's life and circumstances where someone dies when
they would have survived had they been wearing a helmet.

It seems there are some people here who are so terrified that there could be a
positive outcome to wearing a helmet that they will say anything to distract
from that fact.

I don't like helmets.

I don't wear a helmet.

But I don't let the above two facts blind me to the possibility, however remote,
that one day not wearing a helmet could cost me my life.

On Mon, 19 Mar 2007 14:44:00 +0000, Anthony Jones <[email hidden]>

Quoted message said:

Ziggy wrote:

Quoted message said:

Quoted message said:

If you don't believe me, try banging your head firmly against a brick wall
faced with a polystyrene ceiling tile and then against an unfaced brick
wall. Come back and report your findings 😉

If you think you're advancing the whole helmet debate here, you're very much
mistaken.

OK.

Go away and try it, then come back and tell me what you think.

"Ziggy" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Mon, 19 Mar 2007 14:27:26 -0000, "Clive George"
<[email hidden]>
wrote:

Some stuff.

You seem to be labouring under the misapprehension that I'm arguing that
helmet
wearing is a 'good thing'.

I'm not.

I'm just pointing out that there are almost certain to be circumstances
when
wearing a helmet saved someone's life and circumstances where someone dies
when
they would have survived had they been wearing a helmet.

That's better. Trouble is you present it in almost exactly the same terms as
various pro-helmet people use to justify their promotion. And you did
dismiss the "statistics and stuff" bit out of hand.

If you don't want to be misunderstood, be a little more careful what you
write.

cheers,
clive

Ian Smith said:

Ziggy said:

Evidence is, that if you bang something rigid(ish) (such as a
skull) against something solid (such as a kerbstone), it takes a
greater force to damage it if you intersperse something that will
deform on impact between the two experimental objects.

Absolutely. If all you care about is damage to your skull, I agree
that wearing a helmet makes a lot of sense.

Well, that's all I was saying. (Bearing in mind that in a lot of cases a
fractured skull can lead to nasty complications, including death.)

So there was no really no need for a panic team to dive rush in to discredit the
notion that helmets are generally 'a good thing'. That was not what I was
saying.

Ziggy said:

Quoted message said:

Quoted message said:

If you don't believe me, try banging your head firmly against a brick
wall faced with a polystyrene ceiling tile and then against an unfaced
brick wall. Come back and report your findings 😉

If you think you're advancing the whole helmet debate here, you're very
much mistaken.

Go away and try it, then come back and tell me what you think.

Have you tried it?

Anthony

Nick Kew said:

On Mon, 19 Mar 2007 14:17:30 GMT

(Ziggy) said:

Evidence is, that if you bang something rigid(ish) (such as a skull)
against something solid (such as a kerbstone),

I don't do that.

Good!

Quoted message said:

But the last two times I've gone over the handlebars,

I don't do that 😉

Quoted message said:

Quoted message said:

It therefore seems likely that helmets will prevent some number of
head injuries each year and reduce the seriousness of some other
number.

And be the cause of some further number. Statistics say this third
number is the highest.

I'm absolutely prepared to believe that.

Ziggy said:

Ian Smith said:

Ziggy said:

On 19 Mar 2007 13:45:29 GMT, Ian Smith <[email hidden]> wrote:

>But no more true than that it's possible for a lucky rabbit's foot to
>save your life.

I can't really agree with that.

Only under truly bizarre circumstances could a rabbit's foot
save your life.

Eh? You can't agree that it's possible for a rabbit's foot to save
your life, then in the very next sentence you agree that in certain
circumstances it could.

Read what you wrote, and what I said.

I said "it's possible for a lucky rabbit's foot to save your life".
You said "I can't really agree with that".

ie, you do not believe it's possible for a lucky rabbit's foot to save
your life.

You said "Only under truly bizarre circumstances could a rabbit's foot
save your life."

ie, you do believe it's possible for a lucky rabbit's foot to save
your life.

You don't believe it. You do believe it.
And now you say:

Quoted message said:

There is no inconsistency.

So, I say again - make your mind up what you believe, then try again.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

On Mon, 19 Mar 2007 15:34:49 GMT, [email hidden] (Ziggy)

Quoted message said:

On Mon, 19 Mar 2007 14:27:26 -0000, "Clive George" <[email hidden]>
wrote:

Some stuff.

You seem to be labouring under the misapprehension that I'm arguing that helmet
wearing is a 'good thing'.

I'm not.

I'm just pointing out that there are almost certain to be circumstances when
wearing a helmet saved someone's life and circumstances where someone dies when
they would have survived had they been wearing a helmet.

It seems there are some people here who are so terrified that there could be a
positive outcome to wearing a helmet that they will say anything to distract
from that fact.

I don't like helmets.

I don't wear a helmet.

But I don't let the above two facts blind me to the possibility, however remote,
that one day not wearing a helmet could cost me my life.

And that "possibility" is, um, zero (or perhaps negative) -
statistically; at least that's what the best and largest studies show
us. No one quite knows why this is, though following this
counter-intuitive finding there have been some suggestions as to why;
you might find it interesting to inform yourself more fully.

Ian Smith said:

Ziggy said:

Ian Smith said:

On Mon, 19 Mar 2007 14:12:21 GMT, Ziggy <[email hidden]> wrote:
> On 19 Mar 2007 13:45:29 GMT, Ian Smith <[email hidden]> wrote:
>
> >But no more true than that it's possible for a lucky rabbit's foot to
> >save your life.
>
> I can't really agree with that.
>
> Only under truly bizarre circumstances could a rabbit's foot
> save your life.

Eh? You can't agree that it's possible for a rabbit's foot to save
your life, then in the very next sentence you agree that in certain
circumstances it could.

Read what you wrote, and what I said.

I said "it's possible for a lucky rabbit's foot to save your life".
You said "I can't really agree with that".

No, Ian, you actually said "But NO MORE true than that it's possible for a lucky
rabbit's foot to save your life." (Emphasis mine).

It was the relative statement that I didn't agree with as I'm sure should have
been obvious from the next two paragraphs:

Quoted message said:

Only under truly bizarre circumstances could a rabbit's foot save your life.

Quoted message said:

On the other hand, there must be a number of cases worldwide each year, however
small, where a cyclist dies of a head injury where the impact was just hard
enough to be fatal and where even a small layer of foam would have decreased the
effect of the impact at the skull sufficiently to save the cyclists life.

You see?

I disagree with your comparative statement and then illustrate why I disagree
with it.