judith wrote:

Which logically means there is no benefit in wearing a helmet as, if
your proposition is correct, they cannot either be safer than not
wearing them because that would make them less dangerous and hence
safer. The proposition as presented then becomes an oxymoron.

Rubbish - there is evidence that wearing helmets overall reduces the
risk of injury to the head.
#

Where?

judith wrote:
On Thu, 28 Aug 2008 02:09:55 -0700 (PDT), "
wrote:

snip

you can either promote cycling or promote helmets,the two are
incompatible. (Guy Chapman)
Any way your reply is not the point I raised, you cannot advocate the
wearing of something by saying it is no more dangerous than not
wearing it... the converse is then also true, if it is no more
dangerous then it cannot be safer because the act of wearing or not
wearing makes no difference to the risk.

Your statement is an oxymoron.

Sniper8052

If you believe it is an oxymoron - just ignore it.

However, there is evidence that wearing a cycle helmet will reduce the
overall risk of injury to a cyclist.

Where is this evidence?

"judith" wrote in message
...

I understand that that was from an article written specifically for
the CTC as part of their anti-compulsion programme - not a scientific
study. From where did he get the figures?

Here are some facts rather than supposition:

Cycle helmets can reduce the severity of head injuries. Research by
the Transport Research Laboratory in 1994 provided international
evidence of their worth.

A report by the British Medical Association (Cycle Helmets, June 1999)
strongly recommended them.

Incredible. You moan about the lack of links to evidence in Sniper's post,
yet here you are qouting a couple of lines from nowhere at all.

In your first 'fact' note the use of the word 'can', which renders your
point completely useless.

On Thu, 28 Aug 2008 17:33:35 +0100, "Michael C"
wrote:

"judith" wrote in message
.. .
On Wed, 27 Aug 2008 17:43:17 +0100, "Michael C"

I don't think there are any but I don't see how this is relevant. They
might say that they leave the choice up to the rider, but they wouldn't
say
you shouldn't actually wear one.


Of course it is relevant.

If the club believed that the wearing of cycle helmets was more likely
overall to increase your chances of head injury - then they would
recommend not wearing them.

Your lack of logic here is astounding. The clubs can leave the choice up to
the rider.

As it is many (most?) clubs recommend wearing helmets because they
know very well that they are more likely to result in an overall
decrease in the chance of injury to the head.

Here you go again making statements without anything to back them up. They
don't know very well that they are more likely to result in an overall
decrease in the chance of injury to the head, BECAUSE THERE HAS BEEN NO
EVIDENCE THAT SUGGESTS THAT.


Why do many Cycle Clubs recommend people wear them then?
Why do the Police insist that officers on cycles on duty wear them?

Are they wrong to do so?

Are you saying that there is no evidence that cycle helmets will
overall reduce the chance of injury?

What about the BMJ article (D.L.Robinson) where I think from memory it
says that case-control studies show that cyclists who wear helmets
have fewer head injuries than non-helmet wearers - is this not the
case?


--
you can either promote cycling or promote helmets,the two are
incompatible. (Guy Chapman)

On Thu, 28 Aug 2008 16:11:15 +0100, Mike Clark
wrote:

In message
judith wrote:

On Thu, 28 Aug 2008 15:05:11 +0100, Mike Clark
wrote:

In message
judith wrote:

On Thu, 28 Aug 2008 12:05:38 +0100, Mike Clark
wrote:

[snip]

you snipped the citation (and it's open access so you can download and
read it for free!)

so here it is again.

British Medical Journal, (2006) 332: 722-725 "No clear evidence from
countries that have enforced the wearing of helmets" D.L. Robinson

http://www.bmj.com/cgi/content/full/332/7543/722-a


Mike


Yes thanks - I had looked at it - however I did not see that there is
contrary evidence that wearing a helmet increases the risk per se.

Obviously if you looked but did not see you must have failed to
understand.

You may be right - perhaps I didn't understand.
In which case you can perhaps provide the sentence/paragraphs which
does provide evidence that wearing a helmet increases the risk per se.


snip

Let me point you to a follow-up submission by the same author

http://www.bmj.com/cgi/eletters/332/7543/722-a#15405

In particular I would invite you to take a look at Figure 2 which
clearly indicates that from 96/97 to 01/02 the percentage of head
injuries decreased at the same time as the percentage of cyclists
wearing helmets also showed a marked decrease. This data shows that
an improvement (decrease) in the frequency of head injuries is
associated with a reduction in the proportion of cyclists wearing a
helmet.

I do not believe that it shows that at all (perhaps I am naive)

So you can't see both lines coming down over that time period?


I believe I am looking at the graph which you referenced:


Fig 2 Linear Trends in %head injury, vs helmet wearing (%HW) of child
cyclists in Ontario, Canada.

To me this clearly shows the HI trend dropping almost linearly - with
no relationship to the HW graph.

Is that the graph which you are looking at?


--
you can either promote cycling or promote helmets,the two are
incompatible. (Guy Chapman)

On Thu, 28 Aug 2008 17:40:14 +0100, Marc
wrote:

snip

However, there is evidence that wearing a cycle helmet will reduce the
overall risk of injury to a cyclist.

Where is this evidence?


I think from memory DL Robinson in the BMJ says that case-control
studies confirm that cyclists who wear helmets have less head injuries
than those who don't wear helmets.


Have you never seen any similar evidence of this yourself ? - most
odd, I thought that you had assessed all the evidence in order to
judge for yourself. Perhaps you only read the "evidence" which
supports your point of view?


--
you can either promote cycling or promote helmets,the two are
incompatible. (Guy Chapman)

On Thu, 28 Aug 2008 17:41:19 +0100, "Michael C"
wrote:

"judith" wrote in message
.. .

I understand that that was from an article written specifically for
the CTC as part of their anti-compulsion programme - not a scientific
study. From where did he get the figures?

Here are some facts rather than supposition:

Cycle helmets can reduce the severity of head injuries. Research by
the Transport Research Laboratory in 1994 provided international
evidence of their worth.

A report by the British Medical Association (Cycle Helmets, June 1999)
strongly recommended them.

Incredible. You moan about the lack of links to evidence in Sniper's post,
yet here you are qouting a couple of lines from nowhere at all.

In your first 'fact' note the use of the word 'can', which renders your
point completely useless.


I didn't complain about lack of "links" - I complained about no
reference to the source of his comments.

Having given you the titles of journals, I thought that you would be
able to find the relevant bits yourself.



DfT: Bicycle helmets: review of effectiveness

Here are some extracts - save you reading it all:

Bicycle helmets have been found to be effective at reducing the
incidence and severity of head, brain and upper facial injury.
Bicycle helmets have been found to be effective in reducing injury for
users of all ages, though particularly for children.
All studies found evidence of a protective effect with regards to head
injury of helmet wearing in the event of a bicycle crash.
http://www.dft.gov.uk/pgr/roadsafety...ct4726?page=18
(This is not the 1994 paper I was thinking of - it is later)




--
you can either promote cycling or promote helmets,the two are
incompatible. (Guy Chapman)

judith wrote:
On Thu, 28 Aug 2008 17:40:14 +0100, Marc
wrote:

snip

However, there is evidence that wearing a cycle helmet will reduce the
overall risk of injury to a cyclist.
Where is this evidence?


I think from memory DL Robinson in the BMJ says that case-control
studies confirm that cyclists who wear helmets have less head injuries
than those who don't wear helmets.

Not good enough!

PPOR

In message
judith wrote:

On Thu, 28 Aug 2008 16:11:15 +0100, Mike Clark
wrote:
[snip]
Let me point you to a follow-up submission by the same author

http://www.bmj.com/cgi/eletters/332/7543/722-a#15405

In particular I would invite you to take a look at Figure 2 which
clearly indicates that from 96/97 to 01/02 the percentage of head
injuries decreased at the same time as the percentage of cyclists
wearing helmets also showed a marked decrease. This data shows that
an improvement (decrease) in the frequency of head injuries is
associated with a reduction in the proportion of cyclists wearing a
helmet.
[snip]


I believe I am looking at the graph which you referenced:


Fig 2 Linear Trends in %head injury, vs helmet wearing (%HW) of child
cyclists in Ontario, Canada.

To me this clearly shows the HI trend dropping almost linearly - with
no relationship to the HW graph.

Is that the graph which you are looking at?


Yep that is the one.

So I'm glad that you agree that it is evidence for no relationship
between helmet wearing and protection from head injuries.


I suppose it could be claimed as evidence that

(a) cycle helmets worked for a few years and then stopped working and
became dangerous for some reason?

Or alternatively it could be evidence that

(b) other factors apart from cycle helmets are more dominant in a
contributing to accident safety?


My preference as an interpretation is for (b) and this also fits in
rather nicely with the observation that in countries where cycle helmet
wearing is very low, such as The Netherlands and Denmark, that
serious cycle injuries are less frequent than in countries with much
higher rates of cycle helmet usage such as the USA, Canada and the UK.


Mike
--
M.R. Clark PhD, Reader in Therapeutic and Molecular Immunology
Cambridge University, Department of Pathology
Tennis Court Road, Cambridge CB2 1QP
Tel +44 (0)1223 333705 Web http://www.path.cam.ac.uk/~mrc7/

On Thu, 28 Aug 2008 19:51:16 +0100, Mike Clark
wrote:

In message
judith wrote:

On Thu, 28 Aug 2008 16:11:15 +0100, Mike Clark
wrote:
[snip]
Let me point you to a follow-up submission by the same author

http://www.bmj.com/cgi/eletters/332/7543/722-a#15405

In particular I would invite you to take a look at Figure 2 which
clearly indicates that from 96/97 to 01/02 the percentage of head
injuries decreased at the same time as the percentage of cyclists
wearing helmets also showed a marked decrease. This data shows that
an improvement (decrease) in the frequency of head injuries is
associated with a reduction in the proportion of cyclists wearing a
helmet.
[snip]


I believe I am looking at the graph which you referenced:


Fig 2 Linear Trends in %head injury, vs helmet wearing (%HW) of child
cyclists in Ontario, Canada.

To me this clearly shows the HI trend dropping almost linearly - with
no relationship to the HW graph.

Is that the graph which you are looking at?


Yep that is the one.

So I'm glad that you agree that it is evidence for no relationship
between helmet wearing and protection from head injuries.

You said : This data shows that an improvement (decrease) in the
frequency of head injuries is associated with a reduction in the
proportion of cyclists wearing a helmet.

It shows nothing of the sort. It purely shows that there was a steady
decrease in HI over the period under consideration - with no
correlation to the helmet wearing at all.

Why do you think the injuries do not go back up to their original (04)
level in 01/02?