published helmet research - not troll

"Riley Geary" writes:


From NHTSA, we have their official "What's New about Bicycle
Helmets" brochure at
http://www.nhtsa.dot.gov/people/inju...ead/page2.html
that states:

"Why are bicycle helmets so important?
Bicycle helmets can reduce the risk of head injury by up to 85 percent. Most
deaths related to bicycle falls and collisions involve head injuries. This
means that wearing a helmet can save your life."

"Up to 85%" is a pretty weak statment, as is "can save your life." Kind
of like saying "Brand X reduces cavities by up to 80%."

What I wrote was "I don't think anyone seriously claims an 85%
reduction in fatalities, nor in fatal head injuries - that is mostly a
strawman Krygowski et al. like to bring up." A serious claim is
something you'd see in respectable journal, not some brochure or some
random web site.

Mostly you are complaining about advertizing and "Dear Abby" advice.
Oh and the IIHS (Insurance Institute for Highway Safety) is simply
an industry mouthpiece. Of course insurance companies are in favor
of bicycle helmets - it costs them nothing so any reduction in what
they put out in claims contributes to the bottom line.


You mean like the infamous Sachs, et al "study" still available on the bhsi
website at http://www.bhsi.org/stats.htm and still cited by true believers
among helmet promoters that took the original TRT "finding" and extrapolated
it to fatalities with the ludicrous assertion that:

You guys claimed that the BHSI is simply a single individual putting up a
personal web site. Would you mind getting your story straight or at least
consistent? BTW. the title of the page you are complaining about is
"A Compendium of Statistics from Various Sources." That doesn't sound
like the sort of thing anyone should take seriously.



--
My real name backwards: nemuaZ lliB

"Just zis Guy, you know?" writes:

On Tue, 27 Jul 2004 04:47:47 GMT, (Bill Z.)
wrote in message :

If you look at http://www.smf.org/articles/report.html, for example,
the authors (who include ones Krygowski and Kunich regularly
disparage), you'll see a statement that "Overall, helmets were found
to prevent 69 percent of head injuries, 65 percent of brain injuries,
and 74 percent of severe brain injuries

And you believe that? You believe that a polystyrene hat is more
effective in preventing severe brain injury than "superficial cuts and
abrasions"? Because that is what they are saying here.

Snipping midsentence as you just did is dishonest. What you eliminated
is the following:

_*but_* these authors use the following definitions:

* Head injury: All injuries to the forehead, scalp, ears, skull
and brain, including superficial lacerations, abrasions and
bruises on the scalp, forehead and ears, as well as skull
fractures, concussion, cerebral contusions and lacerations and
all intracranial hemorrhages (subarachnoid, subdural, epidural
and intra-cerebral).
* Brain injury: A diagnosis of concussion or more serious
intracranial injury, excluding skull fractures without
accompanying brain injury.
* Severe brain injury: An intracranial injury or hemorrhage,
including all cerebral lacerations/contusions, and subarachnoid,
subdural and extradural hemorrhages.

Grow up, Guy, and stop playing silly games where you misrepresent
what others have said.

--
My real name backwards: nemuaZ lliB

"Just zis Guy, you know?" writes:

On Tue, 27 Jul 2004 02:14:20 GMT, (Bill Z.)
wrote in message :

Like I said: explain how helmets can mitigate rotational forces. On
the one hand they increase the turning moment, and are more likely to
grab the tarmac; on the other, they increase the deceleration time
marginally. So no obvious nett benefit there.

Go read a book on classical mechanics and you might start getting a
clue as to what I'm talking about. Since you lied about my previous
post, I'm going to flush everything else of yours in today's batch
of posts..

Come back when you grow up.

--
My real name backwards: nemuaZ lliB

"Bill Z." wrote in message
...
Joe Riel writes:

Bill Z. wrote:

A substantial impact to the head that is "off center" will apply a far
higher torque than you can possibly be counteracted by your neck
muscles.

It's not clear that peak force (torque) is the definitive measure.
The impulse (force time integral) is significant. The helmet reduces
the peak but increases the time.

And if you increase the time enough, you'll get the same effect as
pushing on your head with a wet noodle. The impulse is roughly
constant - it depends solely on the momentum transferred.

Keep in mind that most materials have an elastic limit. They'll
return to their original shapes if the peak stress is below some
threshold.

Here we go again with Bill and his inability to understand that the foam in
a helmet compresses very closely to 300 gees across it's entire compression
distance.

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

Like I said: explain how helmets can mitigate rotational forces. On
the one hand they increase the turning moment, and are more likely to
grab the tarmac; on the other, they increase the deceleration time
marginally. So no obvious nett benefit there.

Specialized ran some tests to debunk the idea that helmets "grabbed" the
ground and caused increased rotational forces on the brain/head/neck. They
ran all the tests, looked at the data and never published a word of it. That
is significant in my book.

"Tom Kunich" writes:

"Bill Z." wrote in message
...
Joe Riel writes:


Keep in mind that most materials have an elastic limit. They'll
return to their original shapes if the peak stress is below some
threshold.

Here we go again with Bill and his inability to understand that the foam in
a helmet compresses very closely to 300 gees across it's entire compression
distance.

Kunich refuese to admit that the peak force would be higher without
the helmet.

--
My real name backwards: nemuaZ lliB

"Tom Kunich" writes:

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

Like I said: explain how helmets can mitigate rotational forces. On
the one hand they increase the turning moment, and are more likely to
grab the tarmac; on the other, they increase the deceleration time
marginally. So no obvious nett benefit there.

Specialized ran some tests to debunk the idea that helmets "grabbed" the
ground and caused increased rotational forces on the brain/head/neck. They
ran all the tests, looked at the data and never published a word of it. That
is significant in my book.

Yet another conspiracy theory on Kunich's part (if it is even true.)



My real name backwards: nemuaZ lliB

Bill "Evasion" Zaumen. wrote:

And you believe that? You believe that a polystyrene hat is more
effective in preventing severe brain injury than "superficial cuts
and abrasions"? Because that is what they are saying here.

Snipping midsentence as you just did is dishonest.

It would possibly have been, had I been suggesting a different definition of
head injury from the authors' own rather than just saving space, but since I
was working with their definitions, it was emphatically not dishonest.

Now address the point: do you accept those authors' assertion that helmets,
uniquely among personal protective equipment, are more effective against the
most serious injuries than against all injuries including trivial ones? It
is a claim also made by TR&T (85% / 88% in their case).

What you eliminated is the following:
_*but_* these authors use the following definitions:
* Head injury: All injuries to the forehead, scalp, ears, skull
and brain, including superficial lacerations, abrasions and
bruises on the scalp, forehead and ears, as well as skull
fractures, concussion, cerebral contusions and lacerations and
all intracranial hemorrhages (subarachnoid, subdural, epidural
and intra-cerebral).
* Brain injury: A diagnosis of concussion or more serious
intracranial injury, excluding skull fractures without
accompanying brain injury.
* Severe brain injury: An intracranial injury or hemorrhage,
including all cerebral lacerations/contusions, and subarachnoid,
subdural and extradural hemorrhages.

OK, so, restating the question unsnipped (and therefore almost unreadable)
to save your delicate sensibilities: do you seriously believe that helmets
prevent more "intracranial injury or hemorrhage, including all cerebral
lacerations/contusions, and subarachnoid, subdural and extradural
hemorrhages" than they do "injuries to the forehead, scalp, ears, skull and
brain, including superficial lacerations, abrasions and bruises on the
scalp, forehead and ears, as well as skull fractures, concussion, cerebral
contusions and lacerations and all intracranial hemorrhages (subarachnoid,
subdural, epidural and intra-cerebral)"?

It seems to me thoroughly implausible.

Grow up, Guy, and stop playing silly games where you misrepresent
what others have said.

In what way did I misrepresent, precisely?

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

Bill Z. wrote:

Like I said: explain how helmets can mitigate rotational forces. On
the one hand they increase the turning moment, and are more likely to
grab the tarmac; on the other, they increase the deceleration time
marginally. So no obvious nett benefit there.

Go read a book on classical mechanics and you might start getting a
clue as to what I'm talking about.

Bill, I have an engineering degree. I understand classical mechanics. As I
said in the post you are replying to, there is no evidence to support any
mitigating effect on rotational injuries, and none to support helmets making
them worse. There is, in short, no evidence that helmets have any effect on
rotational brain injuries. So, where's your evidence to suggest otherwise?
Which papers show effectiveness in this kind of injury? Please give
citations.

Since you lied about my previous
post, I'm going to flush everything else of yours in today's batch
of posts..

I have been trying not to give you any excuse for your usual evasions in
this subthread, so please provide evidence.

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

"Just zis Guy, you know?" wrote:

In what way did I misrepresent, precisely?

You disagreed with him.
Only liars and frauds disagree with Zaumen and Vandemann.

Mitch.