Trikki Beltran's bad concussion and his helmet

wvantwiller wrote:
John Forrest Tomlinson wrote in
:

On Fri, 15 Jul 2005 23:07:35 -0400, wvantwiller
wrote:

I personally knew at least one child and one father who would be alive
today if they had been wearing helmets after they died from the trauma
of minor bicycle falls;

How do you know that?



Mostly the newspaper articles quoting the doctors that the internal
trauma would probably been prevented if the riders had been wearing
helmets. Both accidents were recent enough to have involved newer
helmets, also.

To put that in perspective: We had one poster here who told of his
doctor's evaluation. He was in a bike crash, went to the emergency
room and was being treated by the ER doctor. He was not wearing a
helmet when he crashed.

The doctor asked him if he had been wearing a helmet. Not wanting to
hear a lecture, he lied and said "Yes."

The doctor told him "It's a good thing. It probably saved your life."

Unfortunately, I don't recall the name of that poster. If he's still
hanging around, perhaps he'll chime in.


Oh, and there's little reason to think a newer generation helmet is
more protective than an older one. If anything, the older ones
probably had more impact protection. Helmet manufacturers are
constantly working to give you more holes and less styrofoam, while
still (just _barely_) passing the ridiculously weak certification
tests.

- Frank Krygowski

Just zis Guy, you know? wrote:
On Fri, 15 Jul 2005 23:07:35 -0400, wvantwiller
wrote:



Why you think something that increases the lever arm won't hurt in
torsional impacts.


Why you think something that dissapates and redistributes the point
stresses that will inevitably also be present in the non-torsional part of
the impact isn't a good thing?


But there is no known case where cyclist safety has improved with
increasing helmet use, so obviously what goes on after the crash is
only part of the story.


I think the pro-helmet lobby has over-emphasized the ability of a
helmet's life saving abilities in a crash. People therefore think that
they can take more risks because the magical foam hat will save them
from harm.

The anti-helmet lobby has under-emphasized the ability of a helmet's
life saving abilities in a crash. They then think that the helmet is
useless in all cases, and fight against them.

The real aspect is that in certain crashes, a helmet does really well,
but not in all cases. The safest is to ride with a helmet, using the
same riding style as if you don't have one.

W

Just zis Guy, you know? wrote:
I submit that on or about Sat, 16 Jul 2005 07:52:57 -0600, the person
known to the court as Rich made a statement
in Your Honour's bundle) to the
following effect:


But you misunderstand. The torsional force is important not because
of its effect on the neck, but because of the differential movement it
causes between the hemispheres of the brain. These torsional forces
are reckoned to be a (some say the) major source of permanent
disabling brain injury.


Total BS.


Plenty of cites are available, but this will do as a quick layman's
guide: http://www.emedicine.com/radio/topic216.htm

Background: Diffuse axonal injury (DAI) is a frequent result of
traumatic deceleration injuries and a frequent cause of persistent
vegetative state in patients. DAI is the most significant cause of
morbidity in patients with traumatic brain injuries, which most
commonly are the result of high-speed motor vehicle accidents.

DAI is a significant medical problem because of the high level of
debilitation of the patient, the stress that the patient's family must
endure when the patient is in a persistent vegetative state, and the
staggering medical cost of sustaining an individual in this state. DAI
typically consists of several focal white matter 1-15 mm lesions in a
characteristic distribution (see below).

Pathophysiology: The pathophysiology of DAI first was described by
Holbourn in 1943 using 2-dimensional gelatin molds. His work led to
the understanding that shear injury is not induced by linear or
translational forces but rather by rotational forces. Sudden
acceleration-deceleration impact can produce rotational forces that
affect the brain. The injury to tissue is greatest in areas where the
density difference is greatest. For this reason, approximately two
thirds of DAI lesions occur at the gray-white matter junction.

The result of shearing forces in areas of greater density differential
is trauma to the axons, which results in edema and axoplasmic leakage
that is most severe during the first 2 weeks after injury. The exact
location of the shear-strain injury depends on the plane of rotation
and is independent of the distance from the center of rotation.
Conversely, the magnitude of injury depends on 3 factors, including
(1) the distance from the center of rotation, (2) the arc of rotation,
and (3) the duration and intensity of the force.

The true extent of axonal injury typically is worse than visualized
using current imaging techniques. On the microscopic level, the axon
may not be torn completely by the initial force, but the trauma still
can produce focal alteration of the axoplasmic membrane, resulting in
subsequent impairment of axoplasmic transport. Axoplasmic swelling
ensues, and the axon then splits in two. A retraction ball forms,
which is a pathologic hallmark of shearing injury. The axon then
undergoes wallerian degeneration. Dendritic restructuring may occur,
with some regeneration possible in mild-to-moderate injury.

Within the basal ganglia, the effect of DAI produces parenchymal
atrophy brought on by shrinkage of astrocytes in the lateral and
ventral nuclei, with sparing of the anterior and dorsomedial nuclei,
the pulvinar, centromedian nuclei, and lateral geniculate bodies.
Cholinergic neurons have been found to be slightly more susceptible to
trauma than neurons belonging to other neurotransmitters. Peripheral
lesions usually are smaller than central lesions. The lesions
typically are ovoid or elliptical, with the long axis parallel to the
direction of the involved axonal tracts. A high association is seen
between thalamic injury and DAI.

Both silver stains and beta-amyloid precursor protein
immunohistochemical staining have proven useful in the pathologic
identification of DAI lesions.

DAI classically was believed to represent a primary injury (occurring
at the instant of the trauma). Currently, however, it is apparent that
the axoplasmic membrane alteration, transport impairment, and
retraction ball formation may represent secondary (or delayed)
components to the disease process.

Guy

Hey Guy, quit confusing perceptions with facts!


Robin Hubert

I submit that on or about Sat, 16 Jul 2005 10:56:21 -0400, the person
known to the court as The Wogster made a
statement in Your
Honour's bundle) to the following effect:

I think the pro-helmet lobby has over-emphasized the ability of a
helmet's life saving abilities in a crash. People therefore think that
they can take more risks because the magical foam hat will save them
from harm.

Seems fair to me :-)

The anti-helmet lobby has under-emphasized the ability of a helmet's
life saving abilities in a crash. They then think that the helmet is
useless in all cases, and fight against them.

Really? Since I don't actually know of anybody in any anti-helmet
lobby, I couldn't say, but I'd be intrigued to know what you would
consider a realistic estimate of the life-saving capabilities of
helmets. I tend to go by the findings of the largest study of its
kind, by Rodgers in 1988, which found no measurable effect on injuries
and a small but significant increase in risk of fatality, which I'm
quite happy to write off as an artifact.

So as far as I'm concerned the effect on serious and fatal injuries is
zero plus or minus blind luck.

The real aspect is that in certain crashes, a helmet does really well,
but not in all cases. The safest is to ride with a helmet, using the
same riding style as if you don't have one.

Yes, I agree with that. Unfortunately it's unlikely to work that way.
Even I (and I think you'd accept I'm as sceptical as anyone) find
myself riding faster when I have my magic foam hat on.

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

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound

"Just zis Guy, you know?" wrote in message
The Wogster made a
statement to the following effect:

The real aspect is that in certain crashes, a helmet does really well,
but not in all cases. The safest is to ride with a helmet, using the
same riding style as if you don't have one.

Yes, I agree with that. Unfortunately it's unlikely to work that way.
Even I (and I think you'd accept I'm as sceptical as anyone) find
myself riding faster when I have my magic foam hat on.


Are you riding faster now with a helmet on than 20 years ago before
decent helmets existed and it was popular to wear one, and do you have
a study showing that faster speeds are more likely to contribute to
brain injury or death over medium speeds?

And charging more for less protection, more marketing. The conspiracy of
ignorance masquerades as common sense.


wrote in message
ps.com...


wvantwiller wrote:
John Forrest Tomlinson wrote in
:

On Fri, 15 Jul 2005 23:07:35 -0400, wvantwiller
wrote:

I personally knew at least one child and one father who would be alive
today if they had been wearing helmets after they died from the trauma
of minor bicycle falls;

How do you know that?



Mostly the newspaper articles quoting the doctors that the internal
trauma would probably been prevented if the riders had been wearing
helmets. Both accidents were recent enough to have involved newer
helmets, also.

To put that in perspective: We had one poster here who told of his
doctor's evaluation. He was in a bike crash, went to the emergency
room and was being treated by the ER doctor. He was not wearing a
helmet when he crashed.

The doctor asked him if he had been wearing a helmet. Not wanting to
hear a lecture, he lied and said "Yes."

The doctor told him "It's a good thing. It probably saved your life."

Unfortunately, I don't recall the name of that poster. If he's still
hanging around, perhaps he'll chime in.


Oh, and there's little reason to think a newer generation helmet is
more protective than an older one. If anything, the older ones
probably had more impact protection. Helmet manufacturers are
constantly working to give you more holes and less styrofoam, while
still (just _barely_) passing the ridiculously weak certification
tests.

- Frank Krygowski

Just zis Guy, you know? wrote:
I submit that on or about Sat, 16 Jul 2005 10:56:21 -0400, the person
known to the court as The Wogster made a
statement in Your
Honour's bundle) to the following effect:


I think the pro-helmet lobby has over-emphasized the ability of a
helmet's life saving abilities in a crash. People therefore think that
they can take more risks because the magical foam hat will save them

from harm.

Seems fair to me :-)


The anti-helmet lobby has under-emphasized the ability of a helmet's
life saving abilities in a crash. They then think that the helmet is
useless in all cases, and fight against them.


Really? Since I don't actually know of anybody in any anti-helmet
lobby, I couldn't say, but I'd be intrigued to know what you would
consider a realistic estimate of the life-saving capabilities of
helmets. I tend to go by the findings of the largest study of its
kind, by Rodgers in 1988, which found no measurable effect on injuries
and a small but significant increase in risk of fatality, which I'm
quite happy to write off as an artifact.

So as far as I'm concerned the effect on serious and fatal injuries is
zero plus or minus blind luck.


Isn't this proof of the magical foam hat (M.F.H.)attitude.
Realistically there should be no increases in fatalities or serious
injuries, if there are, then the study is skewed by people taking more
risks and chances.

There are really about 4 kinds of bike accident.

1) Bike hits another object, rider does a toss over handlebars and lands
nose first, gaining a 3rd degree case of road rash. Helmet effect - none.

2) Bike hits another object, rider does a toss over handlebars, and
while airborne hits another object head first. Helmet effect moderate
to good.

3) Bike hits object and rider is partially crushed against object,
helmet effect none.

4) Operator loses control and bike goes down sideways in a skid. Helmet
effect none.

Out of the 4, a helmet is only involved in one, and it could more often
then not, result in a broken neck as forces are transmitted by the
helmet to the skull, and then to the neck. Gee morgue or paraplegic
wheelchair (like Christopher Reeves), hmmmmm, given those two choices,
the morgue actually sounds better.

The real aspect is that in certain crashes, a helmet does really well,
but not in all cases. The safest is to ride with a helmet, using the
same riding style as if you don't have one.


Yes, I agree with that. Unfortunately it's unlikely to work that way.
Even I (and I think you'd accept I'm as sceptical as anyone) find
myself riding faster when I have my magic foam hat on.

But knowing that the M.F.H., has such little effect, the question is,
why would you take more chances?

W

I submit that on or about 16 Jul 2005 08:34:41 -0700, the person known
to the court as "Carl Sundquist" made a statement
s.com in Your
Honour's bundle) to the following effect:

The real aspect is that in certain crashes, a helmet does really well,
but not in all cases. The safest is to ride with a helmet, using the
same riding style as if you don't have one.

Yes, I agree with that. Unfortunately it's unlikely to work that way.
Even I (and I think you'd accept I'm as sceptical as anyone) find
myself riding faster when I have my magic foam hat on.

Are you riding faster now with a helmet on than 20 years ago before
decent helmets existed and it was popular to wear one,

I ride faster now with one than I do now without one. Specifically, I
corner faster when going down hills.

This applies only to my drop-bar bike. On the recumbent I go faster
than on the wedgie, and haven't noticed a hat / no hat difference.

20 years ago? Can't recall how fast I was back then, but it's
immaterial since i was an early adopter and enthusiastic advocate of
foam hats, so rarely if ever rode without one.

and do you have
a study showing that faster speeds are more likely to contribute to
brain injury or death over medium speeds?

Good point. No. The only differentiating factor which is well
documented is motor vehicle involvement.

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

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound

I submit that on or about Sat, 16 Jul 2005 12:03:03 -0400, the person
known to the court as The Wogster made a
statement in Your
Honour's bundle) to the following effect:

So as far as I'm concerned the effect on serious and fatal injuries is
zero plus or minus blind luck.

Isn't this proof of the magical foam hat (M.F.H.)attitude.
Realistically there should be no increases in fatalities or serious
injuries, if there are, then the study is skewed by people taking more
risks and chances.

Oh sure. I think risk compensation, and propensity to take risk,
varies so widely in cyclists that it is probably impossible to
separate out the effect of helmets in any statistical series. Seems
to me that the risk compensation effect (or whatever else it is)
balances out the benefits so closely as to make the whole thing moot
anyway :-)

There are really about 4 kinds of bike accident.

Oh I have to disagree. I think that if in an average year there are
100,000 bike accidents, then there will be at a first approximation
100,000 different types of bike accidents. No two crashes I've had
have been the same.

This is one reason I think the one-size-fits-all approach is flawed.

The real aspect is that in certain crashes, a helmet does really well,
but not in all cases. The safest is to ride with a helmet, using the
same riding style as if you don't have one.

Yes, I agree with that. Unfortunately it's unlikely to work that way.
Even I (and I think you'd accept I'm as sceptical as anyone) find
myself riding faster when I have my magic foam hat on.

But knowing that the M.F.H., has such little effect, the question is,
why would you take more chances?

Tell me about it. I think it's the separation between the rational
being and the residual animal. But as humans we love to play with
that dichotomy - every time we ride a roller-coaster our analytical
brain is sitting there laughing at the terrified monkey :-)

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

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound

Just zis Guy, you know? wrote:
I submit that on or about Sat, 16 Jul 2005 12:03:03 -0400, the person
known to the court as The Wogster made a
statement in Your
Honour's bundle) to the following effect:


So as far as I'm concerned the effect on serious and fatal injuries is
zero plus or minus blind luck.


Isn't this proof of the magical foam hat (M.F.H.)attitude.
Realistically there should be no increases in fatalities or serious
injuries, if there are, then the study is skewed by people taking more
risks and chances.


Oh sure. I think risk compensation, and propensity to take risk,
varies so widely in cyclists that it is probably impossible to
separate out the effect of helmets in any statistical series. Seems
to me that the risk compensation effect (or whatever else it is)
balances out the benefits so closely as to make the whole thing moot
anyway :-)


Agreed, however the helmet lobbyists seem to push the idea that once you
don the M.F.H. you will be safe in all cases, and that is one of the
reasons people take extra risks......


There are really about 4 kinds of bike accident.


Oh I have to disagree. I think that if in an average year there are
100,000 bike accidents, then there will be at a first approximation
100,000 different types of bike accidents. No two crashes I've had
have been the same.


They may all be different, but they all have similarities as well, which
is why I broke it down, the way I did. MV accidents are the same,
except there are fewer possibilities but more different consequences.
You either hit something, or lose traction. I did want to show that in
some cases the M.F.H. might actually help. Also in those particular
cases, it can also make it worse, i.e. skull fracture versus neck
fracture....


This is one reason I think the one-size-fits-all approach is flawed.


The real aspect is that in certain crashes, a helmet does really well,
but not in all cases. The safest is to ride with a helmet, using the
same riding style as if you don't have one.


Yes, I agree with that. Unfortunately it's unlikely to work that way.
Even I (and I think you'd accept I'm as sceptical as anyone) find
myself riding faster when I have my magic foam hat on.


But knowing that the M.F.H., has such little effect, the question is,
why would you take more chances?


Tell me about it. I think it's the separation between the rational
being and the residual animal. But as humans we love to play with
that dichotomy - every time we ride a roller-coaster our analytical
brain is sitting there laughing at the terrified monkey :-)


I think it's more likely that the M.F.H. lobby has psychologically made
you wonder if maybe the M.F.H. lobby is somehow correct, and that the
M.F.H. will protect you......

W