Helmets

you know? said:

John D'oh has made it a habit to post a one-liner, "Troll.", in
response to any well-argued post disagreeing with him, but I think
we've established by now that this is not an accusation but a
placeholder.

http://www.chapmancentral.co.uk/web/public.nsf/Documents/johndoh

Well done for putting that up so quickly, Guy.

--
Dave...

Get a bicycle. You will not regret it. If you live. - Mark Twain

On Thu, 02 Dec 2004 22:34:57 GMT, Dave Kahn <[email hidden]>

wrote in message : said:

Quoted message said:

http://www.chapmancentral.co.uk/web/public.nsf/Documents/johndoh

Well done for putting that up so quickly, Guy.

Daniel Barlow did most of the work.

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

Quoted message said:

Please could someone post a review of this paper? Is it available
anywhere online, or only to people with access to good libraries? And
might an offprint be available?

Here's the Abstract <URL:http://www.extenza-eps.com/extenza/loadHTML?
objectIDValue=32524&type=abstract> :

The most frequently sustained severe injuries in motorcycle crashes are
injuries to the head, and many of these are caused by rotational force.
Rotational force is most commonly the result of oblique impacts to the
head. Good testing methods for evaluating the effects of such impacts are
currently lacking. There is also a need for improving our understanding
of the effects of oblique impacts on the human head. Helmet standards
currently in use today do not measure rotational effects in test dummy
heads. However rotational force to the head results in large shear
strains arising in the brain, which has been proposed as a cause of
traumatic brain injuries like diffuse axonal injuries (DAI).

This paper investigates a number of well-defined impacts, simulated using
a detailed finite element (FE) model of the human head, an FE model of
the Hybrid III dummy head and an FE model of a helmet. The same
simulations were performed on both the FE human head model and the FE
Hybrid III head model, both fitted with helmets. Simulations on both
these heads were performed to describe the relationship between load
levels in the FE Hybrid III head model and strains in the brain tissue in
the FE human head model. In this study, the change in rotational velocity
and the head injury criterion (HIC) value were chosen as appropriate
measurements. It was concluded that both rotational and translational
effects are important when predicting the strain levels in the human
brain.

"Peter Taylor" <[email hidden]> wrote:
....
| A helmet will not save you from falling under a bus,

Not wearing one might make you or the bus driver take greater care,
meaning the "accident" is avoided completely. If so, your "not helmet"
saved your life.

| My argument is that skin and bones heal. Brain does not. And wearing a
| helmet is just a sensible precaution against suffering an irreversible
| injury.

They're not designed to prevent brain injury. Find me a manufacturer
that claims they are.

| Adults can make up their own mind and weigh up the risks, but for heavens
| sake encourage your kids to wear a properly designed helmet.

I'll do that if you can find me a helmet intended to be effective in
RTAs. Otherwise I'd rather maximise the motivation towards caution in
road users.

--
Patrick Herring, http://www.anweald.co.uk

On Fri, 03 Dec 2004 00:26:19 GMT, [email hidden] (Patrick Herring)

wrote in message : said:

Not wearing one might make you or the bus driver take greater care,

Or indeed you yourself.

"then came ye chavves, theyre cartes girded wyth candels
blue, and theyre beastes wyth straynge horn-lyke thyngs
onn theyre arses that theyre fartes be herde from myles
around." Chaucer, the Sheppey Tales

Ian Smith said:

But conversely, there's no credible way it could make the injuries
worse, unlike helmets.

Possibly you could swallow it and choke. Especially if you'd been
knocked unconscious.

-dan

--
"please make sure that the person is your friend before you confirm"

Ian Smith said:

But conversely, there's no credible way it could make the injuries
worse, unlike helmets.

You've clearly never suffered from a lucky rabbit's foot stuck up your
nostril after a crash

Tony ;-)

Clive George said:

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

Quoted message said:

Quoted message said:

I don't think a rabbit's foot would reduce head injuries in any accident.

Quoted message said:

Now there's a challenge :-)

In the only crash I've been in which I hit my helmeted head, I reduced
head injuries by putting my hand in front of my head. According to
witnesses I was was approaching the van by sliding along on my knees
at a combined realtive approach speed of about 30mph. I was wearing a
car racing helmet (rather stronger than a cycle helmet). I placed my
outstretched hand on the van's headlamp, and proceeded to stove the
whole headlamp assembly in with head, with body weight behind it, to
the extent that it all got bent back and jammed into the front wheel
so the wheel no longer went round. I was knocked out.

How come I was travelling on my knees towards this van? I'd been
knocked off my motorcycle by a bus which "hadn't seen me". Nor,
apparently, had the van, despite my full headlamp beam having been
pointed straight at him.

I've no doubt my hand reduced the severity of the impact (it took it
nearly six months of hard work to recover normal functioning). I'm
sure a rabbit's foot taped to the front of the helmet would have
helped a bit too.

They kept me in hospital for ten days just waiting for the concussion
to develop. They said there was no way I could have been in that sort
of accident and not be suffering from concussion. In fact they
couldn't believe that not only was my skull not cracked but I wasn't
even displaying any obvious symptoms of concussion. The hospital was
well sited to collect lots of crash victims, near a number of "black
spots", so they had a lot of experience.

While I was in hospital I read of the sad case of a learner nurse on a
new moped, wearing a motorcycling helmet, who was intimidated by
traffic into riding rather slowly close to the kerb. She wobbled into
the kerb at about walking speed, wobbled off, fell off, and hit her
head on the kerb edge. Her helmet split open on impact. She suffered
brain damage, never recovered consciousness, was pronounced brain
dead, and her parents gave permission for her organs to be donated.

"You're lucky!" said the other head cases on the ward. "No I'm not," I
said, "I'm sensible. She was wearing a [censored] helmet. The law shouldn't
allow those things to be sold."

But then, car racing helmets are rather more seriously constructed
than toy bicycle helmets, or indeed than motorcycle helmets, which was
why I was wearing the thing, and continued to wear similar successors
for decades, rather than the flimsy stuff permitted by legislation: my
brain was worth the protection.

I've nothing against helmets per se. I'd consider wearing a cycle
helmet if research hadn't so comprehensively shown their
silliness. You don't even need to go into accident statistics, you
simply have to look up impact concussion data and check them against
the design and test criteria for cycle helmets. They're a text book
case of a triumph of marketing over ignorance. But what about all
those research studies which show positive benefit? Well yes, what
about all those research studies which showed that smoking wasn't bad
for you? It's not hard to buy research studies.

--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

Just zis Guy said:

On 02 Dec 2004 17:43:06 GMT, Andy Leighton <[email hidden]>
wrote in message <[email hidden]>:

Quoted message said:

Quoted message said:

it seems that there are confounding factors (be it risk
compensation, rotational injuries or some other factors) that reduce their
effectiveness (to below a significant level) when viewed on whole populations.

Quoted message said:

And there is more discussion of this all the time. There are two
studies into the locations where helmets get hit, and they come out at
an average of about 2/3 of impacts being on the side of the helmet,
not the straight frontal or top impact modelled in the drop tests.
And there is yet another report on oblique impacts out: "Injury
tolerances for oblique impact helmet testing, "Aare M, Kleiven S,
Halldin P. Int J Crashworthiness 2004. I haven't read the original
yet, but the abstracts talk about the current standards not even
measuring oblique / rotational forces (which we knew) despite their
being strongly implicated in the worst kinds of brain injury.

Quoted message said:

We also know that almost all modern helmets have a tendency to grab
tarmac surfaces.

Something which motorcycle helmet makers know about, and take steps to
avoid as far as possible. Shame that bicycle helmet manufacturers
aren't aware of this. Wait a minute! Some of them make *both* good
non-grabby motorcycle helmets *and* crappy grabby bicycle
helmets. What *can* be going on here?

It's called a market. People buy them.
--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

On Fri, 3 Dec 2004 09:50:24 +0000 (UTC), [email hidden] (Chris

Malcolm) said:

They kept me in hospital for ten days just waiting for the concussion
to develop. They said there was no way I could have been in that sort
of accident and not be suffering from concussion.

Impressive. Obviously van headlights make good crumple zones :-)

Guy
--
"then came ye chavves, theyre cartes girded wyth candels
blue, and theyre beastes wyth straynge horn-lyke thyngs
onn theyre arses that theyre fartes be herde from myles
around." Chaucer, the Sheppey Tales

In article said:

Andy Leighton said:

I don't think it is in the same class. Helmets may work in some individual
cases, however it seems that there are confounding factors (be it risk
compensation, rotational injuries or some other factors) that reduce their
effectiveness (to below a significant level) when viewed on whole populations.

I don't think a rabbit's foot would reduce head injuries in any accident.

But conversely, there's no credible way it could make the injuries
worse, unlike helmets.

Risk compensation: believing in your lucky rabbit's foot could encourage you
to take bigger risks, leading to you travelling faster at the time of the
accident, making your injuries worse.
Conversely, the added confidence it gives you could make you cycle better,
avoiding the accident in the first place.

Clearly more research is called for.

"Just zis Guy, you know?" <[email hidden]> wrote:

| On Fri, 03 Dec 2004 00:26:19 GMT, [email hidden] (Patrick Herring)
| wrote in message <[email hidden]>:
|
| >Not wearing one might make you or the bus driver take greater care,
|
| Or indeed you yourself.
|
| "then came ye chavves, theyre cartes girded wyth candels
| blue, and theyre beastes wyth straynge horn-lyke thyngs
| onn theyre arses that theyre fartes be herde from myles
| around." Chaucer, the Sheppey Tales

Not sure what you're saying here: is it that I should trump my way
through the traffic or switch to cart-and-oxen?

--
Patrick Herring, http://www.anweald.co.uk

On Fri, 03 Dec 2004 14:29:58 GMT, [email hidden] (Patrick Herring)

wrote in message : said:

Not sure what you're saying here: is it that I should trump my way
through the traffic or switch to cart-and-oxen?

What I am saying is this: "where did I leave that sigsep?"

Looks like fridge-suck to me...

Guy
--
"then came ye chavves, theyre cartes girded wyth candels
blue, and theyre beastes wyth straynge horn-lyke thyngs
onn theyre arses that theyre fartes be herde from myles
around." Chaucer, the Sheppey Tales

in message <[email hidden]>, Just zis Guy,

you know? (') said:

On Thu, 02 Dec 2004 22:03:12 +0000, Simon Brooke
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

Please could someone post a review of this paper? Is it available
anywhere online, or only to people with access to good libraries? And
might an offprint be available?

I don't have a copy yet, but I am trying to get one.

Twenty-five squids, they want, for an offprint! Ouch!

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; killing [afghan|iraqi] civilians is not 'justice'

in message <[email hidden]>, Just zis Guy,

you know? (') said:

On Fri, 3 Dec 2004 09:50:24 +0000 (UTC), [email hidden] (Chris

Malcolm) said:

They kept me in hospital for ten days just waiting for the concussion
to develop. They said there was no way I could have been in that sort
of accident and not be suffering from concussion.

Impressive. Obviously van headlights make good crumple zones :-)

^^^ ^^^^^^^^^^

IRTA a Dutch gentleman's name, and spent a several of moments trying to
find a parse for the sentence...

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

'Victories are not solutions.'
;; John Hume, Northern Irish politician, on Radio Scotland 1/2/95
;; Nobel Peace Prize laureate 1998; few have deserved it so much

On Fri, 03 Dec 2004 19:53:43 +0000, Simon Brooke
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

IRTA a Dutch gentleman's name, and spent a several of moments trying to
find a parse for the sentence...

Wot, like Hertz van Rental?

Guy
--
"then came ye chavves, theyre cartes girded wyth candels
blue, and theyre beastes wyth straynge horn-lyke thyngs
onn theyre arses that theyre fartes be herde from myles
around." Chaucer, the Sheppey Tales

On Fri, 03 Dec 2004 19:51:19 +0000, Simon Brooke
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

Quoted message said:

I don't have a copy yet, but I am trying to get one.

Twenty-five squids, they want, for an offprint! Ouch!

Well quite. <whisper> there are certain people who have been known to
share papers </whisper>

Guy
--
"then came ye chavves, theyre cartes girded wyth candels
blue, and theyre beastes wyth straynge horn-lyke thyngs
onn theyre arses that theyre fartes be herde from myles
around." Chaucer, the Sheppey Tales

Simon Brooke said:

Twenty-five squids, they want, for an offprint! Ouch!

The authors asked you to pay for the privilege of reading their research?

I'm in the wrong field!

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

"Just zis Guy, you know?" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Fri, 03 Dec 2004 19:53:43 +0000, Simon Brooke
<[email hidden]> wrote in message
<[email hidden]>:

Quoted message said:

IRTA a Dutch gentleman's name, and spent a several of moments trying to
find a parse for the sentence...

Wot, like Hertz van Rental?

Don't forget his brother who says ducky a lot and has a tendancy to wear
sequins.

cheers,
clive

in message <[email hidden]>, James Annan

(') said:

Simon Brooke said:

Twenty-five squids, they want, for an offprint! Ouch!

The authors asked you to pay for the privilege of reading their
research?

The journal publishers, I'm guessing.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

<p>Schroedinger's cat is <blink><strong>NOT</strong></blink> dead.</p>