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  #251  
Old May 18th 17, 06:51 PM posted to rec.bicycles.tech
Duane[_3_]
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Posts: 1,900
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On 18/05/2017 11:50 AM, AMuzi wrote:
On 5/18/2017 10:37 AM, Frank Krygowski wrote:
On 5/17/2017 11:30 PM, wrote:
On Wed, 17 May 2017 22:40:05 -0400, Frank Krygowski
wrote:

On 5/17/2017 9:50 PM, Radey Shouman wrote:
Emanuel Berg writes:

Radey Shouman wrote:

By requiring a head injury, you exclude the
cases where helmets actually prevented head
injury (or where helmets caused a head injury
that would otherwise not have happened).

By requiring an accident, you exclude the
cases where a helmeted rider took more risk
than she otherwise would have, and had
a crash she would have avoided without
a helmet.

By comparing bikers with and without helmets,
you risk comparing two populations that are
quite different, in ability, in age, in their
tendency to follow traffic rules or to seek
medical attention, in economic status, and
many other factors.

Still, it is bikes, helmets, accidents, and
head injuries, as opposed to pedestrians,
MCs, etc.

All of us are pedestrians at some point, so head
injuries to pedestrians
should have some personal interest. Similarly most of
us are drivers,
and almost all are passengers in motor vehicles at least
some of the time.

And who never uses a ladder?

It's reasonable to ask whether wearing a bike helmet
reduces ones
chances of suffering a brain injury, today, this year,
or over a
lifetime. But it's also reasonable to ask, if you're a
health
researcher, what the best way of minimizing brain
injuries over a whole
population, many of whom may not ever ride a bicycle.

Frank seems to think it was purely mercenary, but I
suspect that the
original question in the minds of those who started the
bike helmet
thing was: In what activity with a non-trivial risk of
brain injury can
we actually change human behavior, to use the protective
equipment that
surely will fix the problem?

That might be a possible explanation if the promotions
weren't kick
started almost entirely by Bell Inc.

The very first article I read touting bike helmets was
talking about
Bell Biker helmets, when they first arrived on the
market. (There was
one tiny manufacturer, Skid-Lid, before Bell. I don't
recall anything
but its own ads promoting it.)

Bell soon became a sponsor of Safe Kids Inc. Safe Kids
began lobbying
for mandatory helmets, and we were off to the races, as
they say.

Also, note that the entire industry started in the U.S.,
a country where
bicycling has always been comparatively rare, thus easy
to portray as
dangerous. If public health people were really at the
root of the
promotion, why would it not have happened in those
European countries
where there is lots of cycling, so lots more (purported)
benefit?
Cycling has always been camparatively rare in the USA????

When I was growing up, just about every kid had a bicycle
in Canada -
and it seemed there were a lot more in the USA. Every
school had a
bank of bike racks, and large numbers of kids biked to
school instead
of being ferried in by parents in mini-vans / suvs, cuvs
etc. Every
small town had at least one bicycle shop,
In the summer, there were kids on bikes all over town,
and we biked
out to our favorite fishing holes and swimming holes. The
common bike
was a single speed coaster bike - with 3 speed Sturmey
Archer equipped
bikes a close second, and "french gear" bikes - usually 5
or 10 speed,
but not uncommonly even 3 and 6 speed (3 on the back and 2
on the
crank)


I think you missed the word "comparatively." Bike use in
the U.S. has always been much smaller than in Europe and Asia.

And it's interesting that American kids once rode bikes very
much more than they do now. My friends and I certainly rode
a lot when I was a kid; but the only common warning then was
from a mom saying "Watch out for cars."

Today, warnings come from well-funded institutions pushing
publications saying "You can fall off your bike and die even
in your own driveway! You MUST wear a helmet every time you
ride a bike!"

Do you think there may be a connection between the "Danger!
Danger!" warnings and the drop in kids' bicycling? Just maybe?



True but cultural changes are even larger than that. Military theorists
have been writing about policy effects of an only-child population for
years and then there's modern media which sensationalize crimes against
children (horrible, every one) despite USA children being safer in every
measurable respect than any population ever before in history. How safe?
Mothers can obsess over supposed vaccine side effects and trace
materials in food because they don't have enough real dangers to worry
over.


My kid used to ride all the time. He stopped when his friends thought
it wasn't cool. Cool is sitting around with a cell phone texting each
other. Actually, if he thought cycling was dangerous, he would have
been more likely to do it as it would have been way more cool.

Around here the drop in kids on bikes comes with adolescence. The
younger ones all have bikes. But cycling is pretty common in Quebec.
Maybe it's different in places where cycling is less popular.
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  #252  
Old May 18th 17, 06:52 PM posted to rec.bicycles.tech
SMS
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On 5/18/2017 7:20 AM, Radey Shouman wrote:

snip

I think that was my first point, which you snipped. Not that I agree
that helmet effectiveness is under-estimated.


No one reports head impact crashes where there is no injury. As Jay
pointed out, there are a lot of crashes where a helmet completely
prevents lacerations, and those don't result in an ER visit.

  #253  
Old May 18th 17, 07:58 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
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On 5/18/2017 12:15 PM, jbeattie wrote:
On Thursday, May 18, 2017 at 8:46:49 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:32 AM, sms wrote:
On 5/16/2017 12:24 PM, Radey Shouman wrote:

By requiring an accident, you exclude the cases where a helmeted rider
took more risk than she otherwise would have, and had a crash she
would have avoided without a helmet.

And you have all the crashes that are not reported at all because the
helmet prevented a trip to the emergency room. Helmet effectiveness is
vastly under-estimated because there's no way to determine how many
people don't seek treatment because they have no injury because of the
helmet.


Bull****.

If there were vast numbers of concussions prevented by helmet use, the
number of bike-related concussions in the U.S. would not have risen at
the same time helmets surged in popularity.

From the article "Senseless" in the June 2013 issue of _Bicycling_
magazine: "Here’s the trouble. Stat #3: As more people
buckled on helmets, brain injuries also increased.
Between 1997 and 2011 the number of bike-related
concussions suffered annually by American riders
increased by 67 percent, from 9,327 to 15,546, according to the National
Electronic Injury Surveillance
System, a yearly sampling of hospital emergency
rooms conducted by the U.S. Consumer Product
Safety Commission (CPSC)"

Again, the needle is not even moving in the right direction.

Likewise, if there were lots of lives saved by helmets, bike fatalities
since (say) the mid-1980s should have dropped by a greater percentage
than pedestrian fatalities. But they did not, as shown by
http://vehicularcyclist.com/fatals.html
and http://vehicularcyclist.com/kunich.html


Ordinary helmets don't prevent minor TBIs, although they can prevent skull fracture and serious scalp injury. I've seen some scalp injuries that would make your skin crawl.

Citing to Kunich? Gawd. Go to MedLine: Clinical Surgery; Bicycle helmets work when it matters the most; (2017) 213 AMJLSU 2 413-417:

Results

A total of 6,267 patients were included. About 25.1% (n = 1,573) of bicycle riders were helmeted. Overall, 52.4% (n = 3,284) of the patients had severe TBI, and the mortality rate was 2.8% (n = 176). Helmeted bicycle riders had 51% reduced odds of severe TBI (odds ratio [OR] .49, 95% confidence interval [CI] .43 to .55, P .001) and 44% reduced odds of mortality (OR .56, 95% CI .34 to .78, P = .010). Helmet use also reduced the odds of facial fractures by 31% (OR .69, 95% CI .58 to .81, P .001).

Conclusion

Bicycle helmet use provides protection against severe TBI, reduces facial fractures, and saves lives even after sustaining an intracranial hemorrhage.

• The aim of this study was to assess the association of helmets with severity of traumatic brain injury and facial fractures after bicycle-related accidents.
• Results of our study strongly support our hypothesis that helmet use in bicycle riders with intracranial bleed is independently associated with reduction in overall facial fractures and severity of TBI.
• Injury prevention programs should advocate the use of helmets in bicycle riders especially in the teenage group where least compliance with bicycle helmet use was observed.


Who knows if it's accurate, but I would tend to trust a group of University of Arizona researchers and trauma doctors more than some dopey bloggers.


The "dopey bloggers" were simply posting government statistics, Jay.
Despite lots of studies replicating the 1989 helmet promotion paper by
Thompson & Rivara and getting vaguely similar results, the TBI cases
have _risen_ with massive helmet use; and the fatalities have not fallen
as fast as pedestrian fatalities. You may not like the guy who posted
the numbers, but those ARE the numbers!

The study you linked is very typical, and very similar to the Thompson &
Rivara study that served as its prototype. The T&R "85%"study has
gotten the most discussion in efforts to explain why its predictions
simply don't come true in the real world (and why its results are
officially disowned by the federal government); but the criticisms of
T&R apply to almost all studies on the same model. Here are some of them.

First, if you're studying helmeted vs. non-helmeted cyclists presenting
to ER, are you really studying similar groups? Fatalities are mentioned
above; but as John has noted several times, roughly a quarter of bike
fatalities involve blood alcohol above the legal limit. AFAIK only one
helmet study of this type included alcohol as a confounding factor, and
it found that alcohol use correlated with brain injury; helmet use did
not significantly correlate. More briefly, drunks don't usually wear
helmets, but they affect studies such as the one above.

In the T&R study, other reviewers showed that helmeted kids were seven
times as likely to be presented to ER compared to non-helmeted kids.
Why? In that case, it appeared that kids (and today, adults) in helmets
had significantly better medical insurance, and would appear at ER "just
in case." Non-helmeted kids that presented were in much more serious
crashes overall, since the uninsured probably saved money by treating
minor injuries at home. More briefly, insurance coverage is a
confounding factor that's normally ignored. Did the study above account
for it?

Other confounding factors are likely, such as crash details (wrong way
into an oncoming car, or slip on gravel?), economic status (which goes
beyond insurance), availability of transportation (poor people are less
likely to wear helmets and less likely to have an easy way to get to ER)
and more.

If these confounding factors could all be accounted for - something I
doubt is possible - I suspect these "case control" studies would much
more closely match the observed results on a national scale, which is
that helmets make no great difference overall.

Former pro rider Chris Boardman said "Helmets not even in top 10 of
things that keep cycling safe." They've been heavily promoted for over
25 years and the needle is still moving in the wrong direction, even for
the minuscule portion of serious TBI that happens to bicyclists. Why
are we still giving them any attention?

See
http://road.cc/content/news/111258-c...p-cycling-safe


--
- Frank Krygowski
  #254  
Old May 18th 17, 08:03 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Shimano Headset

On 5/18/2017 1:34 PM, sms wrote:
On 5/18/2017 9:15 AM, jbeattie wrote:

snip

Ordinary helmets don't prevent minor TBIs, although they can prevent
skull fracture and serious scalp injury. I've seen some scalp injuries
that would make your skin crawl.


True. It's popular for AHZs to try to always move the conversation to
TBIs, because it suits their agenda, but the reality is that there are
other types of head injuries as well, and it is necessary for them to
ignore those other types.


Yes, "head injury" is not the same as Traumatic Brain Injury, despite
decades of helmet pushers deliberately conflating the two.

But non-TBI head injuries are things like scrapes, cuts, scratches,
bruises. A scrape on the head is precisely as dangerous as a scrape on
the knee (the most common injury in cycling). And it can be prevented
with many kinds of hats. Guy Chapman posted many times here about his
being "saved" by wearing a wooly cap.

Don't make mountains out of molehills in your effort to get everyone to
wear styrofoam.

--
- Frank Krygowski
  #255  
Old May 18th 17, 08:06 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Shimano Headset

On 5/18/2017 1:52 PM, sms wrote:
On 5/18/2017 7:20 AM, Radey Shouman wrote:

snip

I think that was my first point, which you snipped. Not that I agree
that helmet effectiveness is under-estimated.


No one reports head impact crashes where there is no injury. As Jay
pointed out, there are a lot of crashes where a helmet completely
prevents lacerations, and those don't result in an ER visit.


There are also no reports when a wooly hat prevents a laceration. Guy
Chapman's experience, when he was "saved" by his wooly hat, is in no
database.

The wooly hat manufacturers should learn from the helmet manufacturers.
Think of the marketing possibilities!

--
- Frank Krygowski
  #256  
Old May 18th 17, 09:24 PM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
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On Thursday, May 18, 2017 at 11:58:54 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:15 PM, jbeattie wrote:
On Thursday, May 18, 2017 at 8:46:49 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:32 AM, sms wrote:
On 5/16/2017 12:24 PM, Radey Shouman wrote:

By requiring an accident, you exclude the cases where a helmeted rider
took more risk than she otherwise would have, and had a crash she
would have avoided without a helmet.

And you have all the crashes that are not reported at all because the
helmet prevented a trip to the emergency room. Helmet effectiveness is
vastly under-estimated because there's no way to determine how many
people don't seek treatment because they have no injury because of the
helmet.

Bull****.

If there were vast numbers of concussions prevented by helmet use, the
number of bike-related concussions in the U.S. would not have risen at
the same time helmets surged in popularity.

From the article "Senseless" in the June 2013 issue of _Bicycling_
magazine: "Here’s the trouble. Stat #3: As more people
buckled on helmets, brain injuries also increased.
Between 1997 and 2011 the number of bike-related
concussions suffered annually by American riders
increased by 67 percent, from 9,327 to 15,546, according to the National
Electronic Injury Surveillance
System, a yearly sampling of hospital emergency
rooms conducted by the U.S. Consumer Product
Safety Commission (CPSC)"

Again, the needle is not even moving in the right direction.

Likewise, if there were lots of lives saved by helmets, bike fatalities
since (say) the mid-1980s should have dropped by a greater percentage
than pedestrian fatalities. But they did not, as shown by
http://vehicularcyclist.com/fatals.html
and http://vehicularcyclist.com/kunich.html


Ordinary helmets don't prevent minor TBIs, although they can prevent skull fracture and serious scalp injury. I've seen some scalp injuries that would make your skin crawl.

Citing to Kunich? Gawd. Go to MedLine: Clinical Surgery; Bicycle helmets work when it matters the most; (2017) 213 AMJLSU 2 413-417:

Results

A total of 6,267 patients were included. About 25.1% (n = 1,573) of bicycle riders were helmeted. Overall, 52.4% (n = 3,284) of the patients had severe TBI, and the mortality rate was 2.8% (n = 176). Helmeted bicycle riders had 51% reduced odds of severe TBI (odds ratio [OR] .49, 95% confidence interval [CI] .43 to .55, P .001) and 44% reduced odds of mortality (OR .56, 95% CI .34 to .78, P = .010). Helmet use also reduced the odds of facial fractures by 31% (OR .69, 95% CI .58 to .81, P .001).

Conclusion

Bicycle helmet use provides protection against severe TBI, reduces facial fractures, and saves lives even after sustaining an intracranial hemorrhage.

• The aim of this study was to assess the association of helmets with severity of traumatic brain injury and facial fractures after bicycle-related accidents.
• Results of our study strongly support our hypothesis that helmet use in bicycle riders with intracranial bleed is independently associated with reduction in overall facial fractures and severity of TBI.
• Injury prevention programs should advocate the use of helmets in bicycle riders especially in the teenage group where least compliance with bicycle helmet use was observed.


Who knows if it's accurate, but I would tend to trust a group of University of Arizona researchers and trauma doctors more than some dopey bloggers.


The "dopey bloggers" were simply posting government statistics, Jay.
Despite lots of studies replicating the 1989 helmet promotion paper by
Thompson & Rivara and getting vaguely similar results, the TBI cases
have _risen_ with massive helmet use; and the fatalities have not fallen
as fast as pedestrian fatalities. You may not like the guy who posted
the numbers, but those ARE the numbers!



The study you linked is very typical, and very similar to the Thompson &
Rivara study that served as its prototype. The T&R "85%"study has
gotten the most discussion in efforts to explain why its predictions
simply don't come true in the real world (and why its results are
officially disowned by the federal government); but the criticisms of
T&R apply to almost all studies on the same model. Here are some of them..

First, if you're studying helmeted vs. non-helmeted cyclists presenting
to ER, are you really studying similar groups? Fatalities are mentioned
above; but as John has noted several times, roughly a quarter of bike
fatalities involve blood alcohol above the legal limit. AFAIK only one
helmet study of this type included alcohol as a confounding factor, and
it found that alcohol use correlated with brain injury; helmet use did
not significantly correlate. More briefly, drunks don't usually wear
helmets, but they affect studies such as the one above.

In the T&R study, other reviewers showed that helmeted kids were seven
times as likely to be presented to ER compared to non-helmeted kids.
Why? In that case, it appeared that kids (and today, adults) in helmets
had significantly better medical insurance, and would appear at ER "just
in case." Non-helmeted kids that presented were in much more serious
crashes overall, since the uninsured probably saved money by treating
minor injuries at home. More briefly, insurance coverage is a
confounding factor that's normally ignored. Did the study above account
for it?

Other confounding factors are likely, such as crash details (wrong way
into an oncoming car, or slip on gravel?), economic status (which goes
beyond insurance), availability of transportation (poor people are less
likely to wear helmets and less likely to have an easy way to get to ER)
and more.

If these confounding factors could all be accounted for - something I
doubt is possible - I suspect these "case control" studies would much
more closely match the observed results on a national scale, which is
that helmets make no great difference overall.

Former pro rider Chris Boardman said "Helmets not even in top 10 of
things that keep cycling safe." They've been heavily promoted for over
25 years and the needle is still moving in the wrong direction, even for
the minuscule portion of serious TBI that happens to bicyclists. Why
are we still giving them any attention?


Because they prevent certain injuries. Skip the case studies and go to FEA:

Bicycle helmets are highly effective at preventing head injury during head impact: Head-form accelerations and injury criteria for helmeted and unhelmeted impacts; (2014) 70 ESACAP C 1-7

The protective effect of a helmet in three bicycle accidents—A finite element study; (2016) 91 ESACAP 135-143

There are all sorts of these studies. Not surprisingly, they prove that if you hit your head on a hard object, you're better off if you're wearing a helmet. That's kind of why we have helmets, no?

-- Jay Beattie.

  #257  
Old May 18th 17, 10:37 PM posted to rec.bicycles.tech
[email protected]
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Posts: 3,345
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On Thursday, May 18, 2017 at 10:11:24 AM UTC-7, jbeattie wrote:

I actually hire epidemiologists and biomechanical experts. I also have unfettered MedLine access and access to all the journals published by Elsevier. I don't pretend to know more than the professionals I hire, although I do understand what they tell me. I also don't pretend to be an expert epidemiologist on the internet.

Face includes forehead and brow. My helmet covers my forehead and projects over my brow. I don't know about your helmet. I'm aware of studies going back to '94 (at least) showing that helmets lessen certain facial injuries.. This is not news.


Jay, if you HIRE experts to tell you things exactly why are you so quick to deny knowledge to others because you get it for free?

No a helmet does NOT protect your face or brow. It simply rotates back on your head. I have one of the very few broken bones I've sustained on my brow and I was wearing the best Bell helmet of the time. I was unconscious for over 5 minutes. And as I said, this was a fall onto my face with me turning my head down to "protect" my face at a mere 18" to 2'.

The "facial" injuries you're talking about are the same one's that Frank and I have spoken of in several postings here - if you have a non-serious crash a helmet can protect you somewhat from non-serious injuries.

Isn't that good enough for you? You can only accept a helmet that would save you if a train hit you are 60 mph?
  #258  
Old May 18th 17, 10:46 PM posted to rec.bicycles.tech
[email protected]
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Posts: 3,345
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On Thursday, May 18, 2017 at 10:55:41 AM UTC-7, sms wrote:
On 5/18/2017 7:20 AM, Radey Shouman wrote:

snip

I think that was my first point, which you snipped. Not that I agree
that helmet effectiveness is under-estimated.


No one reports head impact crashes where there is no injury. As Jay
pointed out, there are a lot of crashes where a helmet completely
prevents lacerations, and those don't result in an ER visit.


Exactly WHERE did these life threatening injuries come from in which helmets saved their lives? Why has fatalities for pedestrians come down in a stead line with the introduction of pedestrian lights and bicycle fatalities come down with the growth of cycling and hence the increased familiarity of cyclists on the road?

I want you to explain how suddenly helmets started saving EXACTLY the same numbers of lives so that the reductions were a straight line.

And remember - the use of helmets did NOT increase incrementally but almost immediately among sports riders. And only very slowly among other groups.
  #259  
Old May 18th 17, 10:52 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,345
Default Shimano Headset

On Thursday, May 18, 2017 at 11:58:54 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:15 PM, jbeattie wrote:
On Thursday, May 18, 2017 at 8:46:49 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:32 AM, sms wrote:
On 5/16/2017 12:24 PM, Radey Shouman wrote:

By requiring an accident, you exclude the cases where a helmeted rider
took more risk than she otherwise would have, and had a crash she
would have avoided without a helmet.

And you have all the crashes that are not reported at all because the
helmet prevented a trip to the emergency room. Helmet effectiveness is
vastly under-estimated because there's no way to determine how many
people don't seek treatment because they have no injury because of the
helmet.

Bull****.

If there were vast numbers of concussions prevented by helmet use, the
number of bike-related concussions in the U.S. would not have risen at
the same time helmets surged in popularity.

From the article "Senseless" in the June 2013 issue of _Bicycling_
magazine: "Here’s the trouble. Stat #3: As more people
buckled on helmets, brain injuries also increased.
Between 1997 and 2011 the number of bike-related
concussions suffered annually by American riders
increased by 67 percent, from 9,327 to 15,546, according to the National
Electronic Injury Surveillance
System, a yearly sampling of hospital emergency
rooms conducted by the U.S. Consumer Product
Safety Commission (CPSC)"

Again, the needle is not even moving in the right direction.

Likewise, if there were lots of lives saved by helmets, bike fatalities
since (say) the mid-1980s should have dropped by a greater percentage
than pedestrian fatalities. But they did not, as shown by
http://vehicularcyclist.com/fatals.html
and http://vehicularcyclist.com/kunich.html


Ordinary helmets don't prevent minor TBIs, although they can prevent skull fracture and serious scalp injury. I've seen some scalp injuries that would make your skin crawl.

Citing to Kunich? Gawd. Go to MedLine: Clinical Surgery; Bicycle helmets work when it matters the most; (2017) 213 AMJLSU 2 413-417:

Results

A total of 6,267 patients were included. About 25.1% (n = 1,573) of bicycle riders were helmeted. Overall, 52.4% (n = 3,284) of the patients had severe TBI, and the mortality rate was 2.8% (n = 176). Helmeted bicycle riders had 51% reduced odds of severe TBI (odds ratio [OR] .49, 95% confidence interval [CI] .43 to .55, P .001) and 44% reduced odds of mortality (OR .56, 95% CI .34 to .78, P = .010). Helmet use also reduced the odds of facial fractures by 31% (OR .69, 95% CI .58 to .81, P .001).

Conclusion

Bicycle helmet use provides protection against severe TBI, reduces facial fractures, and saves lives even after sustaining an intracranial hemorrhage.

• The aim of this study was to assess the association of helmets with severity of traumatic brain injury and facial fractures after bicycle-related accidents.
• Results of our study strongly support our hypothesis that helmet use in bicycle riders with intracranial bleed is independently associated with reduction in overall facial fractures and severity of TBI.
• Injury prevention programs should advocate the use of helmets in bicycle riders especially in the teenage group where least compliance with bicycle helmet use was observed.


Who knows if it's accurate, but I would tend to trust a group of University of Arizona researchers and trauma doctors more than some dopey bloggers.


The "dopey bloggers" were simply posting government statistics, Jay.
Despite lots of studies replicating the 1989 helmet promotion paper by
Thompson & Rivara and getting vaguely similar results, the TBI cases
have _risen_ with massive helmet use; and the fatalities have not fallen
as fast as pedestrian fatalities. You may not like the guy who posted
the numbers, but those ARE the numbers!

The study you linked is very typical, and very similar to the Thompson &
Rivara study that served as its prototype. The T&R "85%"study has
gotten the most discussion in efforts to explain why its predictions
simply don't come true in the real world (and why its results are
officially disowned by the federal government); but the criticisms of
T&R apply to almost all studies on the same model. Here are some of them..

First, if you're studying helmeted vs. non-helmeted cyclists presenting
to ER, are you really studying similar groups? Fatalities are mentioned
above; but as John has noted several times, roughly a quarter of bike
fatalities involve blood alcohol above the legal limit. AFAIK only one
helmet study of this type included alcohol as a confounding factor, and
it found that alcohol use correlated with brain injury; helmet use did
not significantly correlate. More briefly, drunks don't usually wear
helmets, but they affect studies such as the one above.

In the T&R study, other reviewers showed that helmeted kids were seven
times as likely to be presented to ER compared to non-helmeted kids.
Why? In that case, it appeared that kids (and today, adults) in helmets
had significantly better medical insurance, and would appear at ER "just
in case." Non-helmeted kids that presented were in much more serious
crashes overall, since the uninsured probably saved money by treating
minor injuries at home. More briefly, insurance coverage is a
confounding factor that's normally ignored. Did the study above account
for it?

Other confounding factors are likely, such as crash details (wrong way
into an oncoming car, or slip on gravel?), economic status (which goes
beyond insurance), availability of transportation (poor people are less
likely to wear helmets and less likely to have an easy way to get to ER)
and more.

If these confounding factors could all be accounted for - something I
doubt is possible - I suspect these "case control" studies would much
more closely match the observed results on a national scale, which is
that helmets make no great difference overall.

Former pro rider Chris Boardman said "Helmets not even in top 10 of
things that keep cycling safe." They've been heavily promoted for over
25 years and the needle is still moving in the wrong direction, even for
the minuscule portion of serious TBI that happens to bicyclists. Why
are we still giving them any attention?

See
http://road.cc/content/news/111258-c...p-cycling-safe


What really makes me question the sanity of the "must wear a helmet" group is that there are NO FACTS that they can understand that show that helmets do very little to nothing.

But the MERE statement that "helmets save lives" is more dependable than St.. Thomas.
  #260  
Old May 18th 17, 11:02 PM posted to rec.bicycles.tech
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On Thursday, May 18, 2017 at 1:24:07 PM UTC-7, jbeattie wrote:
On Thursday, May 18, 2017 at 11:58:54 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:15 PM, jbeattie wrote:
On Thursday, May 18, 2017 at 8:46:49 AM UTC-7, Frank Krygowski wrote:
On 5/18/2017 12:32 AM, sms wrote:
On 5/16/2017 12:24 PM, Radey Shouman wrote:

By requiring an accident, you exclude the cases where a helmeted rider
took more risk than she otherwise would have, and had a crash she
would have avoided without a helmet.

And you have all the crashes that are not reported at all because the
helmet prevented a trip to the emergency room. Helmet effectiveness is
vastly under-estimated because there's no way to determine how many
people don't seek treatment because they have no injury because of the
helmet.

Bull****.

If there were vast numbers of concussions prevented by helmet use, the
number of bike-related concussions in the U.S. would not have risen at
the same time helmets surged in popularity.

From the article "Senseless" in the June 2013 issue of _Bicycling_
magazine: "Here’s the trouble. Stat #3: As more people
buckled on helmets, brain injuries also increased.
Between 1997 and 2011 the number of bike-related
concussions suffered annually by American riders
increased by 67 percent, from 9,327 to 15,546, according to the National
Electronic Injury Surveillance
System, a yearly sampling of hospital emergency
rooms conducted by the U.S. Consumer Product
Safety Commission (CPSC)"

Again, the needle is not even moving in the right direction.

Likewise, if there were lots of lives saved by helmets, bike fatalities
since (say) the mid-1980s should have dropped by a greater percentage
than pedestrian fatalities. But they did not, as shown by
http://vehicularcyclist.com/fatals.html
and http://vehicularcyclist.com/kunich.html

Ordinary helmets don't prevent minor TBIs, although they can prevent skull fracture and serious scalp injury. I've seen some scalp injuries that would make your skin crawl.

Citing to Kunich? Gawd. Go to MedLine: Clinical Surgery; Bicycle helmets work when it matters the most; (2017) 213 AMJLSU 2 413-417:

Results

A total of 6,267 patients were included. About 25.1% (n = 1,573) of bicycle riders were helmeted. Overall, 52.4% (n = 3,284) of the patients had severe TBI, and the mortality rate was 2.8% (n = 176). Helmeted bicycle riders had 51% reduced odds of severe TBI (odds ratio [OR] .49, 95% confidence interval [CI] .43 to .55, P .001) and 44% reduced odds of mortality (OR .56, 95% CI .34 to .78, P = .010). Helmet use also reduced the odds of facial fractures by 31% (OR .69, 95% CI .58 to .81, P .001).

Conclusion

Bicycle helmet use provides protection against severe TBI, reduces facial fractures, and saves lives even after sustaining an intracranial hemorrhage.

• The aim of this study was to assess the association of helmets with severity of traumatic brain injury and facial fractures after bicycle-related accidents.
• Results of our study strongly support our hypothesis that helmet use in bicycle riders with intracranial bleed is independently associated with reduction in overall facial fractures and severity of TBI.
• Injury prevention programs should advocate the use of helmets in bicycle riders especially in the teenage group where least compliance with bicycle helmet use was observed.


Who knows if it's accurate, but I would tend to trust a group of University of Arizona researchers and trauma doctors more than some dopey bloggers.


The "dopey bloggers" were simply posting government statistics, Jay.
Despite lots of studies replicating the 1989 helmet promotion paper by
Thompson & Rivara and getting vaguely similar results, the TBI cases
have _risen_ with massive helmet use; and the fatalities have not fallen
as fast as pedestrian fatalities. You may not like the guy who posted
the numbers, but those ARE the numbers!



The study you linked is very typical, and very similar to the Thompson &
Rivara study that served as its prototype. The T&R "85%"study has
gotten the most discussion in efforts to explain why its predictions
simply don't come true in the real world (and why its results are
officially disowned by the federal government); but the criticisms of
T&R apply to almost all studies on the same model. Here are some of them.

First, if you're studying helmeted vs. non-helmeted cyclists presenting
to ER, are you really studying similar groups? Fatalities are mentioned
above; but as John has noted several times, roughly a quarter of bike
fatalities involve blood alcohol above the legal limit. AFAIK only one
helmet study of this type included alcohol as a confounding factor, and
it found that alcohol use correlated with brain injury; helmet use did
not significantly correlate. More briefly, drunks don't usually wear
helmets, but they affect studies such as the one above.

In the T&R study, other reviewers showed that helmeted kids were seven
times as likely to be presented to ER compared to non-helmeted kids.
Why? In that case, it appeared that kids (and today, adults) in helmets
had significantly better medical insurance, and would appear at ER "just
in case." Non-helmeted kids that presented were in much more serious
crashes overall, since the uninsured probably saved money by treating
minor injuries at home. More briefly, insurance coverage is a
confounding factor that's normally ignored. Did the study above account
for it?

Other confounding factors are likely, such as crash details (wrong way
into an oncoming car, or slip on gravel?), economic status (which goes
beyond insurance), availability of transportation (poor people are less
likely to wear helmets and less likely to have an easy way to get to ER)
and more.

If these confounding factors could all be accounted for - something I
doubt is possible - I suspect these "case control" studies would much
more closely match the observed results on a national scale, which is
that helmets make no great difference overall.

Former pro rider Chris Boardman said "Helmets not even in top 10 of
things that keep cycling safe." They've been heavily promoted for over
25 years and the needle is still moving in the wrong direction, even for
the minuscule portion of serious TBI that happens to bicyclists. Why
are we still giving them any attention?


Because they prevent certain injuries. Skip the case studies and go to FEA:

Bicycle helmets are highly effective at preventing head injury during head impact: Head-form accelerations and injury criteria for helmeted and unhelmeted impacts; (2014) 70 ESACAP C 1-7

The protective effect of a helmet in three bicycle accidents—A finite element study; (2016) 91 ESACAP 135-143

There are all sorts of these studies. Not surprisingly, they prove that if you hit your head on a hard object, you're better off if you're wearing a helmet. That's kind of why we have helmets, no?


What I'm wondering is that I'm the one here that has had the most experience with traumatic brain injury and you and the helmet nuts are the one's telling me that I'm full of ****.

When I was taken to the hospital after being knocked out for over 5 minutes they gave me a complete set of X-rays and CAT scans. Since the only injury was a divot in my brow ridge they let me out the door without a question. About three years ago I had my brother to the same ER and asked the doctors why they didn't keep me overnight to check for concussion damage and he laughed in my face. They don't do that because concussion isn't a traumatic brain injury.

And other doctors have plainly said - concussion is usually worse than a minor skull fracture. The head protects itself by fracturing to reduce the speed of impact so that you DON'T get a concussion.

And yet a bicycle helmet is designed ONLY to reduce minor skull fractures. This means that the impact wearing a helmet is likely to give you the very worst effects of an impact.
 




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