Helmets - split from Hi-Vis discussion

For all discussions about this "lively" subject. All topics that are substantially about helmet usage will be moved here.
Mike Sales
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Re: Helmets - split from Hi-Vis discussion

Post by Mike Sales »

pjclinch wrote: 6 Aug 2021, 3:03pm

It starts off with the two Big Questions, do they help at societal policy and at individual levels. It quickly buries both as "methodologically challenging and contentious"

There are no smoking guns either way.

Pete.
It is odd that when so many people are wearing helmets, many of them by mandation, that we cannot be sure whether or not they work.
It is odd that so much effort and vituperation (from some) is put into getting cyclists to wear helmets when we cannot tell whether they work.
On the other hand we can compare the cyclist casualty rates of countries where helmets are mandated or heavily promoted with the casualty rates of countries where cycle safety efforts go in other directions. That comparison might just have something to tell us about helmet efficacy.
We can also compare the kilometres cycled in helmet countries, compared with those where helmets are little worn.

Spiegelhalter and Goldacre have something to say about why so much fuss is made over a safety device we cannot determine works.

They ask why so much emphasis is put on helmets when the benefits are "too modest to capture compared with other strategies".
They suggest that the reasons for helmet promotion are psychological, cultural and political, and about the public debate on risk.

Helmets on cyclists suggest that cycling is more dangerous than most common activities, which it is not, but the perception does not encourage more people to take up cycling..
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
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pjclinch
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Re: Helmets - split from Hi-Vis discussion

Post by pjclinch »

Mike Sales wrote: 6 Aug 2021, 3:10pm It is odd that when so many people are wearing helmets, many of them by mandation, that we cannot be sure whether or not they work.
It is odd that so much effort and vituperation (from some) is put into getting cyclists to wear helmets when we cannot tell whether they work.
Oh, we know that they work. The old "hit your head against a wall with and without a helmet" test shows that they work to some degree in some situations. We also know they work in making the psychological difference between some people riding and not riding, or just being happier riding. And so on.

The trickier thing is pinning down the particular value of "work" that you're looking for, and as very few people actually bother to do that we end up with a lot of cross-purposed conversations. Alongside the sweeping assumptions of goodness, little tends to be made of the downsides.
But that I can't tell you whether the propensity to helmet use has cost or saved lives in the UK overall is not at all the same thing as not being able to say they don't work at any level. However, working on some level is not the same thing as being a safe bet for a public health and safety policy.
Mike Sales wrote: On the other hand we can compare the cyclist casualty rates of countries where helmets are mandated or heavily promoted with the casualty rates of countries where cycle safety efforts go in other directions. That comparison might just have something to tell us about helmet efficacy.
Not really, it just shows you that other ways are better, not that helmets don't actually work (for some values of "work", as above). You'd need a parallel NL where they made everyone wear helmets to see the real effects of helmets in a Dutch context, and that wouldn't tell you how good they were here. It's not an experiment we can do, in any case.
Mike Sales wrote:We can also compare the kilometres cycled in helmet countries, compared with those where helmets are little worn.
Again, that doesn't tell you much about helmet performance, only that a safety approach primarily dependent on lids isn't as encouraging as one based on making riding pleasant, safe and convenient by design.

Helmets can still "work" in a Dutch-type context. Perhaps the bigger question that helmet proponents tend to avoid is "it might help to some degree, but is it worth doing?". The stock response is "if one life is saved!", yet the people saying that somehow don't see fit to applying it to their use of e.g. stairs.

Pete.
Often seen riding a bike around Dundee...
Mike Sales
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Re: Helmets - split from Hi-Vis discussion

Post by Mike Sales »

I think that the various national experiences can tell us a lot about helmets.
The countries which have near universal wearing show us that helmets are a far from sufficient condition for safe roads for cycling.
Those where despite few helmets, cycling has a low rate of casualties show that helmets are not a necessary condition for safe cycling.
The question is, of course, why we waste all this effort and time on the bloody subject.
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
slowster
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Re: Helmets - split from Hi-Vis discussion

Post by slowster »

Mike Sales wrote: 6 Aug 2021, 4:49pm The question is, of course, why we waste all this effort and time on the bloody subject.
It seems to me that the unwillingness of so many, including so many cyclists, to comprehend and accept the fact that scientific evidence supporting hemet wearing is weak, is itself a phenomenon which is worth spending time and effort to understand.

How do you persuade someone exhibiting cognitive dissonance, that they are exhibiting cognitive dissonance?
Stevek76
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Re: Helmets - split from Hi-Vis discussion

Post by Stevek76 »

I wonder sometimes how so much (inconclusive) evidence exists in the first place. Why is this matter so studied and who on earth is funding it?
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Mike Sales
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Re: Helmets - split from Hi-Vis discussion

Post by Mike Sales »

Motoring helmet.jpg
Driving is dangerous: all motorists should wear head protection. If only one life were saved it would be worth it.


"Davis Craig recommends you wear your Motoring Helmet at all times when motoring but particularly at the following documented high-risk times –



After consuming any alcohol.

When other drivers are likely to have consumed alcohol especially 4.00 pm to 2.00 am Friday and Saturdays.

After dark and during twilight.

In rain or when roads are wet.

During long trips when you may become tired.

Within five kilometres of your home or destination.

Christmas, Easter or long weekends.

If you are under 25 or over 60."
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
drossall
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Re: Helmets - split from Hi-Vis discussion

Post by drossall »

Road safety in general is subject to this kind of thing, because what you're measuring matters so much. For example, for many years, roads got straightened to remove accident blackspots. Which they did. But then people noticed the extra accidents happening further along, because the blackspots were no longer slowing down the traffic. So measures were taken to make going fast harder again. All depends how you're measuring it.
Mike Sales
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Re: Helmets - split from Hi-Vis discussion

Post by Mike Sales »

Here is an interesting article from The New York Times.
Millions of parents take it as an article of faith that putting a bicycle helmet on their children, or themselves, will help keep them out of harm’s way.

But new data raise questions about that assumption. The number of head injuries sustained in bicycle accidents has increased 10 percent since 1991, even as helmet use has risen sharply, according to figures compiled by the Consumer Product Safety Commission. With ridership declining over the same period, the rate of head injuries among bicyclists has increased 51 percent even as the use of bicycle helmets has become widespread.
https://bicycleuniverse.com/head-injuri ... e-helmets/
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
drossall
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Re: Helmets - split from Hi-Vis discussion

Post by drossall »

That's quite an old article. But it perhaps shows some of the issues.

It's stated that there's no doubt that helmets help, but a story is told of someone who incurred an injury with a helmet that would not have occurred without one. You can see in this how both statements could be true at the same time - helmets prevent injuries, and you're less safe with one on. That's because different measures are being used; on the one hand, if I am going to have this accident anyway, am I better off with or without a helmet? On the other, if I go out for a ride on a normal day, when I would certainly be hoping not to have any accident, am I more likely to come back safely with or without a helmet?

I'm not sure I agree with every assertion in that last paragraph, but it does show how complex things get. (And of course the article mentions the magic 88% figure, which is Thompson and Rivara again.)

As I recall it, the debate over helmets arose specifically because people were trying to figure out why studies, and legislatures that were early to introduce compulsion, were not showing the expected benefits.
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Re: Helmets - split from Hi-Vis discussion

Post by pjclinch »

Stevek76 wrote: 6 Aug 2021, 7:52pm I wonder sometimes how so much (inconclusive) evidence exists in the first place. Why is this matter so studied and who on earth is funding it?
Lots of research gets done because someone is interested in doing it. If you're in the medicine game and are collecting hospital data directly from patients the main cost is your own time. Lots of doctors do research on what they think might help their patients, which is Good. They're not necessarily great at designing good studies though...

Pete.
Often seen riding a bike around Dundee...
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