Helmet quote from URCM

Derek C wrote:

In fact, the vast majority of crashed helmets examined in the Hurt
Report showed that they had absorbed about the same impact you'd
receive if you simply tipped over while standing, like a bowling pin,
and hit your head on the pavement. Ninety-plus percent of the head
impacts surveyed, in fact, were equal to or less than the force
involved in a 7-foot drop. And 99 percent of the impacts were at or
below the energy of a 10-foot drop."


Missing the point as usual. How do you square that with 67% of them
suffering head injuries?

Tony

On Aug 9, 10:12Â*am, Tony Raven wrote:
Derek C wrote:

In fact, the vast majority of crashed helmets examined in the Hurt
Report showed that they had absorbed about the same impact you'd
receive if you simply tipped over while standing, like a bowling pin,
and hit your head on the pavement. Ninety-plus percent of the head
impacts surveyed, in fact, were equal to or less than the force
involved in a 7-foot drop. And 99 percent of the impacts were at or
below the energy of a 10-foot drop."

Missing the point as usual. How do you square that with 67% of them
suffering head injuries?

Tony

The relevant passages to what you refer to are as follows:

"The European Union recently released an extensive helmet study called
COST 327, which involved close study of 253 recent motorcycle
accidents in Germany, Finland and the U.K. This is how they summarized
the state of the helmet art after analyzing the accidents and the
damage done to the helmets and the people: "Current designs are too
stiff and too resilient, and energy is absorbed efficiently only at
values of HIC [Head Injury Criteria: a measure of G force over time]
well above those which are survivable."

"The COST study was limited to people who had hit their helmets on the
pavement in their accidents. Of these, 67 percent sustained some kind
of head injury. Even moreã*… percent—sustained leg injuries, and 57
percent had thorax injuries. You can even calculate your odds using
the Injury Severity Score, or ISS. Take the AIS scores for the worst
three injuries you have. Square each of those scores—that is, multiply
them by themselves. Add the three results and compare them with the
ISS Scale of Doom below."


I think the latter paragraph refers to riders who had hit kerbstones
in the course of their crashes. They probably would have suffered much
more severe head injuries if they hadn't been been wearing helmets.
The first paragraph acknowledges that many current motorcycle crash
helmets may be a bit too stiff for many standard accidents.

Derek

On Sat, 7 Aug 2010, Derek C wrote:

Quote from URCM posting by Simon Brooke:

"I had a fall on ice in February and concussed myself badly; next winter
when the ice is about I shall wear a helmet. But I might get studded
tyres as well."

He obviously now believes that helmets help to protect cyclists from
serious head and brain injuries!

Maybe he's just worried about running over his own head with those tyres.

tom

--
Any problem in computer science can be solved with another layer of
indirection. -- David Wheeler

On Mon, 9 Aug 2010 03:10:01 -0700 (PDT), Derek C wrote:

"The COST study was limited to people who had hit their helmets on the
pavement in their accidents. Of these, 67 percent sustained some kind
of head injury. Even moreã*… percent—sustained leg injuries, and 57
percent had thorax injuries. You can even calculate your odds using
the Injury Severity Score, or ISS. Take the AIS scores for the worst
three injuries you have. Square each of those scores—that is, multiply
them by themselves. Add the three results and compare them with the
ISS Scale of Doom below."


I think the latter paragraph refers to riders who had hit kerbstones
in the course of their crashes.

Why?

That is, why do you think the authors of the report are so cretinous
as to take the results for the set of riders who hit kerbstones and
describe it as the set who hit the pavement?

Or is it that you assume they deliberately falsified the report? In
that case, why do you think they described one result as being a
different result? Was it just so that they agreed with the Del
world-view?


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On Aug 9, 8:00*am, Derek C wrote:

Suggest you also read TRL PPR446.

"In the literature reviewed, there is a difference between hospital-
based studies, which tend to show a
significant protective effect from cycle helmets, and population
studies, which tend to show a lower,
or no, effect"

Of course you will prefer the "predictive analysis" (i.e. guess) that
supports your world-view. Feel free to tell us how that squares with
the measured increases in head injury rates in Aus and NZ following
passage of laws there.
--
Guy

Derek C wrote:
On Aug 9, 10:12 am, Tony Raven wrote:
Derek C wrote:

In fact, the vast majority of crashed helmets examined in the Hurt
Report showed that they had absorbed about the same impact you'd
receive if you simply tipped over while standing, like a bowling pin,
and hit your head on the pavement. Ninety-plus percent of the head
impacts surveyed, in fact, were equal to or less than the force
involved in a 7-foot drop. And 99 percent of the impacts were at or
below the energy of a 10-foot drop."
Missing the point as usual. How do you square that with 67% of them
suffering head injuries?

Tony

The relevant passages to what you refer to are as follows:

"The European Union recently released an extensive helmet study called
COST 327, which involved close study of 253 recent motorcycle
accidents in Germany, Finland and the U.K. This is how they summarized
the state of the helmet art after analyzing the accidents and the
damage done to the helmets and the people: "Current designs are too
stiff and too resilient, and energy is absorbed efficiently only at
values of HIC [Head Injury Criteria: a measure of G force over time]
well above those which are survivable."

"The COST study was limited to people who had hit their helmets on the
pavement in their accidents. Of these, 67 percent sustained some kind
of head injury. Even moreã*… percent—sustained leg injuries, and 57
percent had thorax injuries. You can even calculate your odds using
the Injury Severity Score, or ISS. Take the AIS scores for the worst
three injuries you have. Square each of those scores—that is, multiply
them by themselves. Add the three results and compare them with the
ISS Scale of Doom below."


I think the latter paragraph refers to riders who had hit kerbstones
in the course of their crashes. They probably would have suffered much
more severe head injuries if they hadn't been been wearing helmets.
The first paragraph acknowledges that many current motorcycle crash
helmets may be a bit too stiff for many standard accidents.

Derek


Another Derek cut and paste special showing an ability to cut and paste
without understanding.

Its your own invention that they hit kerbstones in the course of their
crashes and not related to anything in the report

But you still haven't explained why if 99% of hits were well within the
designed capability of the helmets, 67% of them suffered head injuries.


And look what else COST 327 found:

"Rotational acceleration was identified by the accident analysis to be a
principal cause of head injury."

Now where have we read about rotational brain injuries and helmets
before I wonder?


Tony

On 9 Aug, 06:18, Derek C wrote:
On Aug 8, 11:18*pm, Adam Lea wrote:



On 08/08/2010 18:27, Peter Clinch wrote:

Derek C wrote:
Quote from URCM posting by Simon Brooke:

"I had a fall on ice in February and concussed myself badly; next
winter
when the ice is about I shall wear a helmet. But I might get studded
tyres as well."

He obviously now believes that helmets help to protect cyclists from
serious head and brain injuries!

Oh. So it's not /possible/ he'd be wearing it to protect him mainly from
minor injuries?

You're very good at putting thoughts into folks' heads. Shame there
aren't many in yours...

Pete.

Don't the arguments about risk compensation, increased risk of
rotational injury, and increasing the size & weight of the head making
it more likely the head will hit the ground still apply though? Having
said that, when cycling on ice it is likely that you would be going slow
enough that should you fall and hit your head, the impact would be
within the design limits of the helmet.- Hide quoted text -

- Show quoted text -

Actually it makes little difference if you fall off your bike at 2 mph
or 40 mph. It is only the height from which you fall and the rate of
any subsequent decelerations that matters. My cycle helmet weights
about 300g, whereas a typical human head weighs somewhere between 4.5
and 5.0kg, so a cycle helmet only adds about 6% to its mass and 1" to
its radius.

.

How come it's safer for motorcyclists to wear a helmet (*it's
mandatory) yet when one is launched from a push bike there is an
argument against the helmets viability.

Seems to me a flying body in search of voilent ground contact is going
to experience pain however it's launched.

"Peter Clinch" wrote in message
...

The main point (I would /guess/ it's up to Simon to really say) is the
liklihood of needing protection. And people fall off quite a bit on ice,
and they actually don't fall off much on normal roads. You're more likely
to hit your head if you fall off, than if you don't fall off.


implicit in that is an acceptance that helmets provide protection, if you
fall off: Some here explicitly deny that that is the case

pk

pk wrote:
"Peter Clinch" wrote in message
...

The main point (I would /guess/ it's up to Simon to really say) is the
liklihood of needing protection. And people fall off quite a bit on
ice, and they actually don't fall off much on normal roads. You're
more likely to hit your head if you fall off, than if you don't fall off.


implicit in that is an acceptance that helmets provide protection, if
you fall off: Some here explicitly deny that that is the case

So who are the "some"?

Further note that "some protection" is not "necessarily useful
protection in any case"

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

On Mon, 9 Aug 2010 17:17:56 +0100, pk wrote:
"Peter Clinch" wrote in message
...

The main point (I would /guess/ it's up to Simon to really say) is the
liklihood of needing protection. And people fall off quite a bit on ice,
and they actually don't fall off much on normal roads. You're more likely
to hit your head if you fall off, than if you don't fall off.


implicit in that is an acceptance that helmets provide protection, if you
fall off: Some here explicitly deny that that is the case

I don't think I've ever seen anyone claim they provide no protection
at all in any circumstances. Can you cite an example of such a claim?

The normal claim is that either they offer no significant protection
to the serious injuries that matter (ie, very good at preventing minor
injuries that may be painful but are not life threatening, but little
use at preventing or mitigating the injuries that kill people), or
that they have as much disbenefit as benefit (ie, they exacerbate as
many injuries as they mitigate, or that they cause as many new
injuries as they mitigate). I've seen plenty of that, but I don't
think any of the case you seem to be thinking of.

regards, Ian SMith
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