From: Derek C on
On 7 Apr, 18:04, n...(a)cam.ac.uk wrote:
> In article <1b11cb23-e7a6-4ace-bc82-fe6f57f9d...(a)x3g2000yqd.googlegroups.com>,
> Derek C  <del.copel...(a)tiscali.co.uk> wrote:
>
>
>
> >The problem is that just gently toppling off your bike at low speed
> >and striking your head on a paving stone or the road can cause a
> >possibly fatal skull fracture. As a child I managed to fracture my
> >upper jawbone and damage my teeth when I skidded off my bike rounding
> >a corner at quite low speed and struck a kerbstone with my bare head.
> >I was also mildly concussed. That was before cycle helmets were
> >available BTW.
>
> No, that is one problem.  Another is that bicycle helmets make it
> more likely that you will strike your head, and increase the impact
> when you do.
>
> That excludes various other effects, such as whether they are more
> likely to make the rider careless, or to encourage motorists to
> endanger the cyclist.
>
> The result is that we simply do not know whether wearing a bicycle
> helmet is likely to increase or reduce the risk of brain damage.
> Either is possible, but the statistics indicate that their effect
> is very small, whichever way it is.
>
> Regards,
> Nick Maclaren.

Typical psycholist reply!

Derek C
From: nmm1 on
In article <111a41e2-e1ef-4b15-8836-4db839a26882(a)8g2000yqz.googlegroups.com>,
Derek C <del.copeland(a)tiscali.co.uk> wrote:
>>
>> >The problem is that just gently toppling off your bike at low speed
>> >and striking your head on a paving stone or the road can cause a
>> >possibly fatal skull fracture. As a child I managed to fracture my
>> >upper jawbone and damage my teeth when I skidded off my bike rounding
>> >a corner at quite low speed and struck a kerbstone with my bare head.
>> >I was also mildly concussed. That was before cycle helmets were
>> >available BTW.
>>
>> No, that is one problem. =A0Another is that bicycle helmets make it
>> more likely that you will strike your head, and increase the impact
>> when you do.
>>
>> That excludes various other effects, such as whether they are more
>> likely to make the rider careless, or to encourage motorists to
>> endanger the cyclist.
>>
>> The result is that we simply do not know whether wearing a bicycle
>> helmet is likely to increase or reduce the risk of brain damage.
>> Either is possible, but the statistics indicate that their effect
>> is very small, whichever way it is.
>
>Typical psycholist reply!

I don't think that you can spell "statistician" :-) I am not the
only one who has come to that conclusion.


Regards,
Nick Maclaren.
From: john wright on
On 07/04/2010 18:04, nmm1(a)cam.ac.uk wrote:
> In article<1b11cb23-e7a6-4ace-bc82-fe6f57f9dc72(a)x3g2000yqd.googlegroups.com>,
> Derek C<del.copeland(a)tiscali.co.uk> wrote:
>>
>> The problem is that just gently toppling off your bike at low speed
>> and striking your head on a paving stone or the road can cause a
>> possibly fatal skull fracture. As a child I managed to fracture my
>> upper jawbone and damage my teeth when I skidded off my bike rounding
>> a corner at quite low speed and struck a kerbstone with my bare head.
>> I was also mildly concussed. That was before cycle helmets were
>> available BTW.
>
> No, that is one problem. Another is that bicycle helmets make it
> more likely that you will strike your head, and increase the impact
> when you do.
>
> That excludes various other effects, such as whether they are more
> likely to make the rider careless, or to encourage motorists to
> endanger the cyclist.

This is ISTR quite a large effect when one considers seat belts in cars
and helmets for motor cyclists. Both are known to increase speed and
other risk laden behaviour.


--
John Wright

Use your imagination Marvin!

Life's bad enough as it is - why invent any more of it.
From: Derek C on
On 7 Apr, 18:12, n...(a)cam.ac.uk wrote:
> In article <111a41e2-e1ef-4b15-8836-4db839a26...(a)8g2000yqz.googlegroups.com>,
> Derek C  <del.copel...(a)tiscali.co.uk> wrote:
>
>
> >> >The problem is that just gently toppling off your bike at low speed
> >> >and striking your head on a paving stone or the road can cause a
> >> >possibly fatal skull fracture. As a child I managed to fracture my
> >> >upper jawbone and damage my teeth when I skidded off my bike rounding
> >> >a corner at quite low speed and struck a kerbstone with my bare head.
> >> >I was also mildly concussed. That was before cycle helmets were
> >> >available BTW.
>
> >> No, that is one problem. =A0Another is that bicycle helmets make it
> >> more likely that you will strike your head, and increase the impact
> >> when you do.
>
> >> That excludes various other effects, such as whether they are more
> >> likely to make the rider careless, or to encourage motorists to
> >> endanger the cyclist.
>
> >> The result is that we simply do not know whether wearing a bicycle
> >> helmet is likely to increase or reduce the risk of brain damage.
> >> Either is possible, but the statistics indicate that their effect
> >> is very small, whichever way it is.
>
> >Typical psycholist reply!
>
> I don't think that you can spell "statistician" :-)  I am not the
> only one who has come to that conclusion.
>
> Regards,
> Nick Maclaren.- Hide quoted text -
>
> - Show quoted text -

I am a professional scientist with a Masters degree, and have used
statistical data for most of my career, thank you very much. The
telling statistic for me is the Police report that suggests that 10
-16 % of cyclists who died principally of head injuries probably would
have survived if they had worn helmets (subject to the usual medical
uncertainties). I shall continue to wear a helmet (my choice).

Derek C

From: nmm1 on
In article <0ad927b2-c9c4-44bd-860f-db5d91c5c936(a)x3g2000yqd.googlegroups.com>,
Derek C <del.copeland(a)tiscali.co.uk> wrote:
>
>I am a professional scientist with a Masters degree, and have used
>statistical data for most of my career, thank you very much. The
>telling statistic for me is the Police report that suggests that 10
>-16 % of cyclists who died principally of head injuries probably would
>have survived if they had worn helmets (subject to the usual medical
>uncertainties). I shall continue to wear a helmet (my choice).

Hmm. If you have actually looked at that claim and failed to spot
the large number of serious statistical defects in it, then your
understanding of statistics is vastly less than you think it is.
It's not quite fair to call it statistical nonsense, but it's pretty
close to it.

Even if it were a reliable estimate (it isn't, but let's skip that),
it ignores the question of how much more likely helmet wearers are
to suffer a major head impact in the first place. The population
statistics indicate that the increase in that may well be comparable,
so the aggregate benefit is close to nil. Which is the REAL issue.

Notice that I am not making any comment on your choice to wear a
helmet, or carry a rabbit's foot, but merely attempting to correct
your erroneous claims.


Regards,
Nick Maclaren.