"Tilly" <
[email protected]> wrote in message
news:
[email protected]...
> On Sat, 02 Jul 2005 13:31:52 +0100, "Just zis Guy, you know?"
> <[email protected]> wrote:
>
> >I am open to persuasion. At least, I think I am. I have been
> >persuaded to change my mind once on this issue, after all.
>
> How about a little anecdotal evidence based on my limited experience
> as a cycling instructor.
>
> I have now instructed for 32 hours, 23 hours on road and 9 hours in
> the playground. 31 hours have been with children with at least some
> experience, and 1 hour with a complete novice.
>
> If I multiply the number of children in each group by the number of
> hours I get a total of 154 cycling hours: 1 cycling hour for a
> complete novice and 153 cycling hours for children with some
> experience. Of those 153 cycling hours 44 have been in the playground
> and 109 on road.
>
> There have been a total of six incidents involving a child losing
> control of their bike and the bike ending up on the ground. Only one
> incident resulted in any noticeable injury, a slight graze treated
> with an antiseptic wipe, for all other incidents there were no
> noticeable injuries.
>
> 5 incidents occurred in the playground, 1 incident on the road.
>
> 2 incidents occurred to a complete novice, 4 to children with some
> experience.
>
> Dividing cyclist hours by incidents we have:
>
> 1 incident every 8.8 playground cyclist hours;
> 1 incident every 109 road cyclist hours.
>
> 1 incident every 38.25 some experience cyclist hours;
> 2 incidents every complete novice cyclist hours.
>
> I conclude on this very low data that a child is about 12 times more
> likely to have an incident in the playground than on the road, and
> that a novice cyclist is about 76.5 times more likely to have an
> incident than a cyclist with at least some experience.
>
> This anecdotal evident supports that which I have already said: a
> child is more likely to be injured in the playground when cycling
> skills are being challenged than on the road where real life
> situations are being explored. And that a novice is more likely to
> suffer an injury than a cyclist with some experience.
>
> It also supports CTUK's risk assessment: for a complete novice the
> risk of a fall is high, for all other riders the risk is very low.
However, you will agree that the evidence is anecdotal based on a very small
sample -- hence, possibly not particularly informative.
> Can we agree that it is far more likely for a complete novice to
> suffer a fall?
This seems likely.
> Can we then go on to agree that it is far more likely for a complete
> novice to suffer a head injury?
I'm not sure we can. Novices are likely to be travelling very slowly.
Indeed, learning to ride a bike is largely about having the confidence and
the control to go fast enough so as not to fall off. Slow speed falls seem
to predominantly result in knee and hand/arm injuries. ***
However, it has to be accepted that, if the probability of a head injury is
about the same for a novice as for an experienced cyclist (which I doubt but
for which I have no data) then your hypothisis would be correct.
> Can we also agree that for the type of fall likely to be suffered by a
> complete novice helmets are most effective.
No -- for the reasons stated above. The falls will be predominantly low
speed. They will predominantly be in a 'safe place' (i.e. should be devoid
of kerbs etc.)
> Can we then go on to agree a wording to the effect of: *While cycling
> is a safe and healthy activity, it makes good sense for complete
> novices to wear helmets when learning to ride a bicycle in a school
> playground.*
Insufficient data to judge.
And that is the problem. Too many people jump to conclusions for which
there is insufficient evidence -- indeed I can be accused of doing it above
(see ***) The only thing that I think we can say is that many parents may
feel more comfortable if their little bundle of genetic inheritance has some
protective gear on. I suspect (but have no evidence) that wrist, elbow and
knee pads would be more useful.
T
PS -- I did suffer a fairly major fall aged 11. Broken arm, broken teeth,
lacerations (fairly minor though quite scary enough for my Gran) to face,
arms and knees -- slight concussion. All (except for the teeth that had to
be crowned) mended naturally with a vanishingly small amount of scaring. I
have no evidence -- but given the exact form of the injuries I suspect that
a helmet would have been of very limited effect. It would have not
protected my arm (which did its job of breaking my fall), or knees. It
might have protected my forehead (where the lacerations were very minor) and
reduced the concussion at the expense of tipping my head further back so
exposing my chin and mouth to additional damage. In extremis it may have
caused some neck injuries.
Statistically insignificant -- but can you imagine the lecture Gran would
have got from a modern triage nurse?
