Another Helmet Thread

Jay Beattie writes:

On Sunday, June 30, 2013 2:41:47 AM UTC-7, SMS wrote:
On 6/29/2013 10:40 PM, Dan wrote:



http://heapro.oxfordjournals.org/content/22/3/191.full


snip



Somehow I don't think this study will be featured on the AHZ website.

We really should skip the "AHZ" bit and probably change it to "AMHLZ." I don't think anyone is against helmets per se.



Consider: If no MHL were ever possible, and practical,
comfortable, inexpensive, 100% effective helmets were
feasible, would Frank have a problem with them?

snip

On 01/07/13 14:01, Frank Krygowski wrote:
On Sunday, June 30, 2013 10:15:48 PM UTC-4, Jay Beattie wrote:

O.K., back to this one:



http://www.sciencedaily.com/releases...cience+News%29


I've discussed that one. It doesn't consider the true comparison between a helmeted head and an unhelmeted one, which is really the issue. It ignores the difference in target size, it ignores the structure of the brain inside the skull, it ignores the protective (evolutionary) mechanisms of the low-friction scalp layers, it uses a smooth surface as the impact target...

Why do you like that? Just because it's pro-helmet? Surely it doesn't take an engineering or medical education to tell how unrealistic it is!

I don't know why it is so hard to accept that a helmet can reduce the incidence of skull fracture.

I don't think anyone is doubting that a helmet "can" reduce the incidence of skull fracture. The questions are these: First, what's the numerical value of "can"? (A Zippo lighter "can" stop a bullet to the heart. It's happened.) Second, why is the supposed value applicable only to bicycling, and not to activities that cause far, far more brain injury deaths?

Again, if you going head first in to the pavement -- helmet or no helmet? http://www.youtube.com/watch?v=_DfiNZJK96I

Hmm. Any evidence of risk compensation there?

Not that it's necessarily a bad thing. The problem is really risk OVER-compensation. If that guy repeated that "trick" on a much longer, steeper downhill, he'd probably be dead. (Let me know if you doubt that.) Yet there are plenty of people taking that risk every day. Why? Partly because they believe their helmet makes them nearly invulnerable.

You can disagree with the text of this video, but it does include images of preventable injuries -- wounds that would have been prevented with a helmet.


Are you _sure_ those are all bicycling wounds? Recall, way over 98% of such injuries in the U.S. have nothing to do with bicycles. The fixation on bicycle injuries, while pretending other head injuries don't exist, is yet more "bicycling is dangerous" nonsense.

When, oh when, will helmet proponents finally work to protect the great majority of all those OTHER hapless victims? Why, if only ONE life can be saved...

- Frank Krygowski

On 01/07/13 14:01, Frank Krygowski wrote:
On Sunday, June 30, 2013 10:15:48 PM UTC-4, Jay Beattie wrote:

O.K., back to this one:



http://www.sciencedaily.com/releases...cience+News%29



I've discussed that one. It doesn't consider the true comparison
between a helmeted head and an unhelmeted one, which is really the
issue. It ignores the difference in target size, it ignores the
structure of the brain inside the skull, it ignores the protective
(evolutionary) mechanisms of the low-friction scalp layers, it uses a
smooth surface as the impact target...


That's funny. We evolved "low-friction scalp layers", presumably from
millions of years of skidding along some rough surface on our head.

--
JS

On 01/07/13 14:11, Frank Krygowski wrote:
On Sunday, June 30, 2013 7:00:41 PM UTC-4, James wrote:

Another quote from the same article...



"Bicycle-helmet standards ...



The key to Snively's method was a test in which he dropped helmets

straight down onto a flat anvil and other metal shapes. A metal
headform

inside the helmet registered the impact. Snively estimated that a
naked

head struck the surface with a force more than 1,000 times greater
than

gravity, or 1,000g, which is lethal. He required that a helmet
protect

the skull by decreasing the impact force to less than 300g, a
number

well below the point at which researchers believed critical head

injury�then defined mainly as skull fracture�occurred.

I don't doubt that the author of that article believes the standard
is based on just skull fracture. However, that's not the way other
sources explain it.

And consider: If skull fracture were the real criterion, why would
the standard test use a solid magnesium headform and measure
deceleration? Why would it not use something replicating a human
skull, and measure breakage?

It seems to me that testers need apparatus that yields both repeatable
measurements and is not (possibly) destroyed with every test. I imagine
an accurate model of a human skull is not so easy to reproduce (WRT how
hard must I hit it to break it), and then to calibrate a model - you'd
need to break it, which kinda renders it useless for further testing ;-)

Every batch of bicycle helmets that is imported into Australia and sold,
has had a sample tested to ensure that that batch passes the required
tests and a special silver foil sticker attached as proof that the
helmet meets the standards requirements.

I can just see them doing that with breakable head models at $10,000 each.

--
JS.

On 01/07/13 15:10, Dan wrote:


Consider: If no MHL were ever possible, and practical,
comfortable, inexpensive, 100% effective helmets were
feasible, would Frank have a problem with them?


Probably, because their mere presence on the shop shelf is indication
enough that riding a bicycle is terribly dangerous, and might put
someone off.

--
JS

On 6/30/2013 10:15 PM, Jay Beattie wrote:
On Saturday, June 29, 2013 4:58:24 PM UTC-7, Phil W Lee wrote:
Frank Krygowski considered Sat, 29 Jun 2013

14:32:31 -0700 (PDT) the perfect time to write:



On Saturday, June 29, 2013 2:56:54 PM UTC-4, Jay Beattie wrote:
On Saturday, June 29, 2013 8:43:56 AM UTC-7, frank Krygowski wrote:
On Saturday, June 29, 2013 10:41:14 AM UTC-4, Jay Beattie wrote:
Drug testing bears little resemblance to the retrospective and case studies used In the helmet literature.
Of course. There's no practical way to do a double-blind helmet study.
I have yet to see clinical trials or bio testing or animal testing of helmets -- rat helmets? In fact, the closest thing to FDA-like testing of helmets is the biomechanical testing using cadaver skulls tending to show that helmets are effective.
Let's talk about the "biomechanical testing using cadaver skulls tending to show that helmets are effective." What tests are you referring to, exactly?
http://thejns.org/doi/full/10.3171/2012.8.peds12116
Yep, I thought it would be that one.
Any specific thoughts on it?
They tested (dead) children's skulls to show that the helmets gave the

same protection against laboratory testing to them as to metal skull

forms. No attempt was made to realistically simulate a real incident.



Conclusion: helmets meet testing standards, even if a cadaver skull

is substituted for a metal head form.





More policy based evidence making.

They looked for a test they knew it could pass, and it did so.
O.K., back to this one:

http://www.sciencedaily.com/releases...cience+News%29

I don't know why it is so hard to accept that a helmet can reduce the incidence of skull fracture. Again, if you going head first in to the pavement -- helmet or no helmet? http://www.youtube.com/watch?v=_DfiNZJK96I

Because Forester says that all you need is his book and you can cycle
safely. Saying that helmets are useful goes against the boss. Same
with bike lanes or paths or anything else.

You can disagree with the text of this video, but it does include images of preventable injuries -- wounds that would have been prevented with a helmet.

http://www.youtube.com/watch?v=gxOeKwVVCVg

-- Jay Beattie.

does Beattie wear a helmet ?

what type ?

Mine (Bell Nbar discount) sits on muh white water canoe in rack, at hand but unused only on dirt n chip seal.

and Dano ?

On 6/30/2013 9:49 PM, Jay Beattie wrote:

It is uncontroverted that helmets prevent certain injuries. Say that. It will set you free. Resist the urge to make any statement about the risks of walking, gardening or other activities. We're just talking about the protective benefits of helmets.

He's already done the first part pretty much. That's _why_ he always has
the irresistible urge to make the statements about pedestrian helmets,
gardening helmets, driving helmets, etc..

On 6/30/2013 11:44 PM, James wrote:
On 01/07/13 15:10, Dan wrote:


Consider: If no MHL were ever possible, and practical,
comfortable, inexpensive, 100% effective helmets were
feasible, would Frank have a problem with them?


Probably, because their mere presence on the shop shelf is indication
enough that riding a bicycle is terribly dangerous, and might put
someone off.

True, it's the same reason you see the 'voluntary helmet use is a silent
vote for compulsion' from some of the AHZs.

The ironic thing is that there are many activities where protective
equipment is available but often not required (at least for adults), and
no one is screaming about how the availability of such equipment makes
others think that the activity is exceptionally dangerous. We went
kayaking on Saturday. I can't recall there ever being a drowning in the
slough where we were. The rental companies train participants in how to
prevent a capsize and the slough isn't very wide or deep, yet almost
everyone wears a PFD even though PFD's aren't that comfortable.

On 7/1/2013 3:51 AM, Duane Hébert wrote:
On 6/30/2013 10:15 PM, Jay Beattie wrote:
On Saturday, June 29, 2013 4:58:24 PM UTC-7, Phil W Lee wrote:
Frank Krygowski considered Sat, 29 Jun 2013

14:32:31 -0700 (PDT) the perfect time to write:



On Saturday, June 29, 2013 2:56:54 PM UTC-4, Jay Beattie wrote:
On Saturday, June 29, 2013 8:43:56 AM UTC-7, frank Krygowski wrote:
On Saturday, June 29, 2013 10:41:14 AM UTC-4, Jay Beattie wrote:
Drug testing bears little resemblance to the retrospective and
case studies used In the helmet literature.
Of course. There's no practical way to do a double-blind helmet
study.
I have yet to see clinical trials or bio testing or animal
testing of helmets -- rat helmets? In fact, the closest thing to
FDA-like testing of helmets is the biomechanical testing using
cadaver skulls tending to show that helmets are effective.
Let's talk about the "biomechanical testing using cadaver skulls
tending to show that helmets are effective." What tests are you
referring to, exactly?
http://thejns.org/doi/full/10.3171/2012.8.peds12116
Yep, I thought it would be that one.
Any specific thoughts on it?
They tested (dead) children's skulls to show that the helmets gave the

same protection against laboratory testing to them as to metal skull

forms. No attempt was made to realistically simulate a real incident.



Conclusion: helmets meet testing standards, even if a cadaver skull

is substituted for a metal head form.





More policy based evidence making.

They looked for a test they knew it could pass, and it did so.
O.K., back to this one:

http://www.sciencedaily.com/releases...cience+News%29


I don't know why it is so hard to accept that a helmet can reduce the
incidence of skull fracture. Again, if you going head first in to the
pavement -- helmet or no helmet?
http://www.youtube.com/watch?v=_DfiNZJK96I

Because Forester says that all you need is his book and you can cycle
safely. Saying that helmets are useful goes against the boss. Same
with bike lanes or paths or anything else.

LOL, but to be fair, Forester, and others, do point out the differences
in cycling between The Netherlands and the U.S., including the
difference in speed and facilities which greatly reduce the need for
helmets.

Forester writes: "The maximum safe speed for Dutch voonerven has been
given as 8 mph. Average travel speeds on Dutch urban bikepaths are
universally described as very slow, probably below 10 mph. On the other
hand, speeds of American bicycle commuters, now easily measured with
electronic speedometers, typically are in the 16-22 mph range. Dutch
cyclists tolerate their low speeds for two reasons: travel times are not
great because they travel short distances and motoring is so
inconvenient that it would probably take longer. American cyclists would
not tolerate Dutch speeds because of the longer distances they must
travel. The facilities, traffic rules and speed-controlling attitudes
that are acceptable to one nation are obviously unacceptable to another."

Similarly, Peter French, co-convenor of CBD BUG, an Australian advocacy
group which focuses on bike use issues within the CBD (Central Business
District) stated: "If you look at the countries where there's really
high levels of cycling, such as the Netherlands and Denmark, they have
much smaller proportions of people being killed or injured over there,
even though they don't wear helmets. It is because their governments
have focused on safety programs which target traffic speeds and
separating cyclists from fast moving traffic."

Of course every time "The Netherlands" is brought up in the context of
helmets, by the AHZs, these differences are conveniently ignored.

What Frank doesn't want to undertand is that there are two distinct
aspects of bicycle safety.

The first aspect is preventing crashes by:

1. Increased bicycle facilities including bike lanes and bike paths.

2. Driver and cyclist education.

3. Increased law enforcement.

4. Increasing motorist awareness of the presence of cyclists via the use
of better lighting, including daytime lighting, loud horns, and visible
clothing.

The second aspect is mitigating the results of crashes by using safety
equipment such as helmets.