Helmet redux

On Thu, 02 Jun 2005 14:53:35 -0500, catzz66
wrote:

People wearing helmets are proclaiming to the world: "I'm doing something
dangerous."

This is one of the statements where I disagree. You have no more
justification for it that I would have in saying all nonwearers are
foolhardy risk takers.

Really? So can you name any other non-dangerous activity for which
you regard the wearing of protective headgear as a "reasonable
precaution?"

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 CHS, Puget Sound

Rich Clark wrote:


People wearing helmets are proclaiming to the world: "I'm doing something
dangerous." There is no evidence I'm aware of to make such a statement any
more true of cycling than it is of driving.



This is one of the statements where I disagree. You have no more
justification for it that I would have in saying all nonwearers are
foolhardy risk takers. There are enough of us here who can state that
we personally did have an accident where helmets helped and that we
consider them to be a reasonable precaution to take when riding, nothing
more, nothing less. We'd have a better chance for dialogue without the
hype.

Just zis Guy, you know? wrote:
Sorry, but your proposed mechanism for overcoming the deficiencies in
the science is markedly worse than the imperfect science that we
currently have. If you are honest with yourself you will admit this.

Once again- I am only arguing for using the anecdotes for constructing
a hypothesis. How can I make it more clear?


Can't be done. And in the absence of this, abandoning science for
anecdote is a step in the wrong direction.

See my reply above!

Here are some downsides for you:
o cost, calculated as exceeding the average benefit in injuries saved

To me the studies are flawed so the calculation prove little or
nothing.

You have better data? No.

No. That's why we need to get it

You need to remember that mountain biking is not all
biking :-)

Actually now I'm purely a roadie :-)

o sends the message that cycling is dangerous, which it is not

We have different perceptions on this. I don't hink it sends that
message at all.

OK, so do you wear one when walking on roads with motor traffic? Or
when travelling in the car? Or around the house? These activities
have comparable risks of head injury. By wearing a helmet for only
one of them, we give the impression that it is uniquely dangerous -
which it isn't.

I guess my oint is that since the studies are flawed we have no idea
what the relative risk might be.


See why we need statistics and data, not anecdote?

See answer #1 above!


No, anecdote further obfuscates the situation. There is no way I ca
think of that bad science is made better by adding non-science!

See answer #1 above.


how come there is no known case where cyclist
safety has improved with increasing helmet use? How come cost-benefit
analysis shows that they cost more than they save in injury
treatments?

Well, I don't know the real answer. And when a proper study is executed
you may well turn out to be correct. But right now I don't see any such
rigorous studies so there is nothing out there provign anything.

Once again, you need to ask yourself what standard you are setting for
a "proper" study.

Pretty high, because absent that we have this debate without valid
data. It can't go very far- at least to my mind.



But then you suggest that in the absence of a "proper" study we revert
to something markedly worse than the "improper" studies. That makes
no sense!


See answer #1 above.


You surely cannot be under any illusion that anecdote has a validity
comparable with whole population and times series data? I refuse to
believe that anyone is that naive!

See answer # 1 above

I think we have a pretty good idea by now, we have after all around
thirty years of data to go on.

But flawed data!!

Wouldn't we all. But we also have to recognise that such data may
never become available due to irreconcilable practical and ethical
difficulties.

But let's stop arguing from flawed data.
And let's stop misrepresenting the arguments of others. For example how
often in your post have you accused me of reverting to anecdotal
evidence over scientific data when in fact I have clearly stated that I
am proposing the anecdotal evidence only as way to construct a null
hypothesis. Without such a null hypothesis how could you construct a
valid statistacal study?

As to the issue of only a double blind study with random assignment
would "prove" the question. I'll argue against that. There is no reason
why a prospective study that uses multi variate matching could not
address the question quite well. It's when you try to do data mining on
extant data sets that you have real problems with the matching.

Just zis Guy, you know? wrote:
On Thu, 02 Jun 2005 14:53:35 -0500, catzz66
wrote:


People wearing helmets are proclaiming to the world: "I'm doing something
dangerous."


This is one of the statements where I disagree. You have no more
justification for it that I would have in saying all nonwearers are
foolhardy risk takers.


Really? So can you name any other non-dangerous activity for which
you regard the wearing of protective headgear as a "reasonable
precaution?"



That really is not the question.

gds wrote:
Well the extant helmet thread is getting quite long and the "debate'
remains quite heated. I've raised a point (in favor of voluntary
helmet use) a number of times and it has never had a direct response.
So I thought I'd try it again in a new thread.

I'm not at all convinced a new thread was necessary. But:...


For a moment let us put aside all of the published research - both pro
& con. My issue is the personally witnessed events where a helmet is
percieved to have prevented or reduced an injury. aI think that this
type of data is improtant in individual decsions on helmet use.

In my own case I have seen many crashes over the years but only two in
which I am completely convinced that a helmet prevented injury. In one
instance I was the rider. I came off my bike on a single track and my
head smashed into a large boulder alongside the trail. The helmet
worked as designed. The hard shell shattered and the foam inner had a
large dent. I had no injury to my head whatsoever.

I witnessed a similar case in which a companion came off his bike and
his head impacted the curb. This was long ago and the helmet was the
type with the styrofoam core with a nylon cover. In this instance the
helmet also performed as designed and the foam broke up absorbing the
shock of the strike but there was no injury.

Let me tell two crash stories, one short and one long.

The first is the last time I hit my head falling off a bike. It was
about 40 years ago. I was delivering newspapers by bike in the winter.
I slipped on some ice, slid sideways then fell directly backwards.
The back of my head hit the sidewalk, but not very hard. I remember
thinking "Ouch. I wonder if I'll have a bump on my head from that?"
But I didn't.

If I _had_ worn a helmet? The thickness of the helmet would have
guaranteed a much harder impact between the helmet and the ground. I
would have had a less concentrated load on my scalp, but I can't say if
the acceleration suffered by my brain would have been greater or less -
I suspect it might have been greater. I'm _sure_ the stress on my neck
would have been much higher, perhaps seriously higher. All in all, I'm
glad I didn't wear a helmet. But if I'd worn one? I'm _sure_ you'd
say it had protected me.


Second, longer story. Others have read this befo

My family and a some friends were leaving a restaurant in a nearby big
city, walking back toward our car. We saw a bus at the side of the
road just ahead, and we saw a car going the same direction pass the
bus.

Just as the car got to the front of the bus, a college kid zoomed
across in front of the bus, going about 12 mph. The car hit him
broadside.

We saw the impact from behind the car and we heard the sickening crash.
The car screetched to a halt. We saw the kid's body tossed into the
air, completely above the car. We heard later that he landed on his
head on the street in front of the car.

As soon as I saw the impact, I ran back to the restaurant and called
911 to report the fatality, then I ran back to reluctantly view the
carnage. But there was no carnage, no fatality. The car's grill was
destroyed, the hood smashed, the windshield destroyed, but the kid was
sitting on a wall at the sidewalk. He'd walked their on his own power.

An off-duty EMT who happened to pass by was holding his neck to
immobilize it. Cops and ambulance arrived, and they strapped him to a
board to take him to the ER. But except for a scratch on his head from
the windshield wiper (Head injury!!!!) he was perfectly fine. We
called the next day, and he was back in classes.

If he'd been wearing a helmet, EVERYBODY would have said the helmet not
only helped, but it saved his life. It was obvious from the damage to
the car, the height to which he was thrown, the subsequent landing on
his head...

But he had no helmet.

What's weirder, nobody even mentioned the lack of a helmet. Not the
EMT, the cops, the ambulance guys - nobody. Why? Because the kid
wasn't on a bike. Like the great majority of non-motorist traffic
victims, he was on foot. He'd jogged across in front of that bus.

When you see a bike incident where you _know_ a helmet helped, think
about this example. Think about what you _really_ know.

So, my thought is that modern, light weight helmets can, in some cases
prevent head injuries. And modern light weight helmets now are so light
and have so much air flow that the "discomfort factor" is very low.
Thus, I don't see much of a down side.

I'll agree they _can_ help. And although the discomfort varies greatly
from person to person and situation to situation, they're certainly not
uncomfortable when you're not exerting yourself in the heat. So I
don't see much downside either... meaning, of course, I don't see why
people don't wear them all the time!

Oddly, it's a rare helmet promoter who uses that idea. Most people
think they should be used _only_ while riding a bike. I think they
have the mistaken idea that cycling is an unusual source of serious
head injuries. I think they got that idea from the helmet salesmen.

Of course, it's false. Cycling is no worse for serious head injuries
than many other activities for which helmets are _never_ proposed.

All this argument over study methodolgies, compulsion causing less
cycling, and the idea that there are more head injuries in motor
vehicles seem to me to be simply changing the subject.

Not at all! That is, not if what you're really worried about is head
injuries. If you're simply bent on making cycling look bad, whether or
not it causes such injuries, then I suppose concentrating only on
cycling makes sense. But if two different activities both cause, say,
0.5 serious head injuries per million hours activity, why promote a
helmet for one, but not the other?

(BTW, that number isn't the correct one; my data on that is in my other
office. I'll double check it later, if you like.)


Bicycle helemts
do add some measure of observable benefit. Now the debate of just how
much that benefit might be is valid.

Sorry, you are confidently excluding the possibility that they provide
no measurable benefit. You must understand that some studies have
found exactly that: no measurable benefit.

But as I and others have witnessed
events with such benefit and the citations of helmets causng accidents
are extremely rare or invole unsupervised childrren (another separate
issue) it goes against all intuiton that there is NO benefit.

Intuition ain't science! If you want to judge things based on
intuition, give up penicillin for your next infection; go with Bach
Flower Remedies instead. (Google it.)

I prefer science.

- Frank Krygowski

wrote:


If I _had_ worn a helmet? The thickness of the helmet would have
guaranteed a much harder impact between the helmet and the ground.

Please look up the mening of "guarantee" Seriously, from the info given
the concept of gurantee does not apply.

I
would have had a less concentrated load on my scalp, but I can't say if
the acceleration suffered by my brain would have been greater or less -
I suspect it might have been greater. I'm _sure_ the stress on my neck
would have been much higher, perhaps seriously higher. All in all, I'm
glad I didn't wear a helmet.

You are pretty sure it wouldn't help to have a helmet based on no real
relevant information to reach that conclusion. I'm not arguing that a
helemt would surely have been bettr but i don't see how you could
possible reach the conclusion that "I'm sure the stress..." etc.




Second, longer story. Others have read this befo


So, my thought is that modern, light weight helmets can, in some cases
prevent head injuries. And modern light weight helmets now are so light
and have so much air flow that the "discomfort factor" is very low.
Thus, I don't see much of a down side.

I'll agree they _can_ help. And although the discomfort varies greatly
from person to person and situation to situation, they're certainly not
uncomfortable when you're not exerting yourself in the heat. So I
don't see much downside either... meaning, of course, I don't see why
people don't wear them all the time!


And that is why good studies need to be done.

Oddly, it's a rare helmet promoter who uses that idea. Most people
think they should be used _only_ while riding a bike. I think they
have the mistaken idea that cycling is an unusual source of serious
head injuries. I think they got that idea from the helmet salesmen.

Of course, it's false. Cycling is no worse for serious head injuries
than many other activities for which helmets are _never_ proposed.

All this argument over study methodolgies, compulsion causing less
cycling, and the idea that there are more head injuries in motor
vehicles seem to me to be simply changing the subject.

Not at all! That is, not if what you're really worried about is head
injuries. If you're simply bent on making cycling look bad, whether or
not it causes such injuries, then I suppose concentrating only on
cycling makes sense. But if two different activities both cause, say,
0.5 serious head injuries per million hours activity, why promote a
helmet for one, but not the other

Look you will not pass any logic class this way. Helemets are either
worthwhile while cycling or not. Making the arguemnt about relative
risk is simply not the issue. You may correct. It may well be that
getting out of bed is more dangerous than cycling. But that is a
separate argument.


(BTW, that number isn't the correct one; my data on that is in my other
office. I'll double check it later, if you like.)


Sorry, you are confidently excluding the possibility that they provide
no measurable benefit. You must understand that some studies have
found exactly that: no measurable benefit.

Agreed. Measurable benefit is my prejudice. But I'm also arguing for a
gwell designed study to settle the question-not dependnce on flawed
studies on either side of the question


But as I and others have witnessed
events with such benefit and the citations of helmets causng accidents
are extremely rare or invole unsupervised childrren (another separate
issue) it goes against all intuiton that there is NO benefit.

Intuition ain't science! If you want to judge things based on
intuition, give up penicillin for your next infection; go with Bach
Flower Remedies instead. (Google it.)

I prefer science.

Of course, But intuition often leads to good science. Your example is
perfect. Fleming witnessed the effects of penicillin (at that point
only intuition!!) and then designed studies that scientifically
demonstrated the effect.

"catzz66" wrote in message
...
Rich Clark wrote:


People wearing helmets are proclaiming to the world: "I'm doing something
dangerous." There is no evidence I'm aware of to make such a statement
any more true of cycling than it is of driving.



This is one of the statements where I disagree.

That was two statements. Which one are you disagreeing with? The one where I
characterize the effect of helmet wearing on an observer? Or the one where I
state my unawareness of evidence proving that cycling is dangerous?

You have no more justification for it that I would have in saying all
nonwearers are foolhardy risk takers.

I am utterly baffled by what part of what I said this is supposed to be
analogous to.

There are enough of us here who can state that
we personally did have an accident where helmets helped

You know that by having reproduced the accident without a helmet and
comparing the results? Or are you simply making the common error of
confusing "belief" with "knowledge"?

and that we consider them to be a reasonable precaution to take when
riding, nothing more, nothing less.

Why is something reasonable in one context and not reasonable in another? If
helmet use is "reasonable" in an activity where the risk is [xx]%, why isn't
it "reasonable" in all activities where the risk is [xx]% or greater?

I suspect that you are again confusing concepts: this time, "reason" with
"intuition."

We'd have a better chance for dialogue

I think that here you are confusing the concepts of "dialogue" and "shouting
match."

without the hype.

What did I say that you believe is an exaggeration? Your use here of the
word "hype" puzzles me. I don't know what you mean.

RichC

gds wrote:

If I _had_ worn a helmet? The thickness of the helmet would have
guaranteed a much harder impact between the helmet and the ground.

Please look up the mening of "guarantee" Seriously, from the info given
the concept of gurantee does not apply.

I think it's pretty much guaranteed that the impact between the helmet and
ground would be zero if it were not present

--
Benjamin Lewis

Although the moon is smaller than the earth, it is farther away.

Rich Clark wrote:
Rich Clark wrote:
People wearing helmets are proclaiming to the world: "I'm doing something
dangerous." There is no evidence I'm aware of to make such a statement
any more true of cycling than it is of driving.



catzz66 replied:
This is one of the statements where I disagree.

Rich Clark wrote:
That was two statements. Which one are you disagreeing with?



Sorry, it was this one: People wearing helmets are proclaiming to the
world: "I'm doing something dangerous."

Benjamin Lewis wrote:
I think it's pretty much guaranteed that the impact between the helmet and
ground would be zero if it were not present

So, do you argue that all helmets should wear heads?