Evaluating the impact of cycle helmet use...

For all discussions about this "lively" subject. All topics that are substantially about helmet usage will be moved here.
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[XAP]Bob
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Re: Evaluating the impact of cycle helmet use...

Post by [XAP]Bob »

pjclinch wrote: 16 Jul 2020, 8:39am Most typically cycling according to the National Standards for Cycle Training is seen as using 2 positions, Primary and Secondary. Secondary is a whole can of worms as to where it effectively is (I was involved in a consultation over teaching positioning earlier this year, it's not just a case of cut and paste from Cyclecraft) but Primary is generally reasonably easy to pin down as the middle of your lane.
--8<--
(The Cycling Scotland position teaching looks to be heading for a Secondary that's taught as at least a metre, rather than Cyclecraft's 50cm)
Interesting definitions...
I generally work on the basis of whether I choose to cycle in the left tyre track (secondary) or the right tyre track (primary) on the road - I do sometimes take the centreline of the lane, but it's not that often (usually not a great surface, and often slightly raised compared with either side, so it doesn't really hold the trike)
Although on a 'bent (especially a trike) it's very rare to get bad close passes (comparing between the same cyclist riding the same commute on mixed vehicles for a several years).

I do make sure that I return to secondary when it's (potentially) safe for the following vehicle to overtake, and obviously avoid the road craters as best I can.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
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Re: Evaluating the impact of cycle helmet use...

Post by Vorpal »

thirdcrank wrote: 10 Jun 2021, 2:16pm
The utility cyclist wrote: 11 Jul 2020, 8:34am
All helmet wearers and those that push for people to wear them whilst cycling do massive harm to society as a whole never mind other people riding bikes helmeted or not. That's not opinion, it's a fact.
I'm not sure if it's good form to quote this as the poster seems to have left the forum but he's also been a strong supporter of the environment for cyclists in Denmark. A little bird sent me this helmet promotion propaganda published by the Danish Road Safety Council.

https://www.youtube.com/watch?v=0m-c4GixUpg
I thought that was rather funny, but of course it is promoting helmets. The Danish equivalent of the DfT & highways authorities have generally been pretty keen to promote helmets. I suspect that is one of the reasons Danish researchers study why they shouldn't. :lol:
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50sbiker
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Re: Evaluating the impact of cycle helmet use...

Post by 50sbiker »

Go scrape your forehead along the road...With and without helmet...Then tell me it makes no difference wearing a helmet.
slowster
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Re: Evaluating the impact of cycle helmet use...

Post by slowster »

50sbiker wrote: 26 Jun 2021, 10:30am Go scrape your forehead along the road...With and without helmet...Then tell me it makes no difference wearing a helmet.
Go learn about proper evidence based science.
Maillot Rouge
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Re: Evaluating the impact of cycle helmet use...

Post by Maillot Rouge »

slowster wrote: 26 Jun 2021, 1:50pm
50sbiker wrote: 26 Jun 2021, 10:30am Go scrape your forehead along the road...With and without helmet...Then tell me it makes no difference wearing a helmet.
Go learn about proper evidence based science.
You don’t really need science to tell you that in that scenario a helmet would stop your head getting cut or grazed.Common sense tells you that?
drossall
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Re: Evaluating the impact of cycle helmet use...

Post by drossall »

I agree, any people planning to lie down and scrape their heads along the road probably should consider wearing cycle helmets. But you need to know whether that is representative of what might happen if you go cycling. That means whether that is the kind of thing that happens in real accidents, and whether other things happen that should also be considered. Which is why people try to look at overall figures and what the effects of helmets tend to be.

And that takes us back to what Goldacre says (which I think has been mentioned already), and for that matter what Chris Boardman said.

You also, by the way, need to know whether modern helmets will do better than, say, the old hairnets that racers used to wear. Those were designed precisely for the scraping scenario. They are much mocked now, by people who make the contrary assumption that crashes are all about direct impacts on the head.
slowster
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Re: Evaluating the impact of cycle helmet use...

Post by slowster »

Maillot Rouge wrote: 26 Jun 2021, 4:26pm You don’t really need science to tell you that in that scenario a helmet would stop your head getting cut or grazed.Common sense tells you that?
You need science to tell you the significance of such a scenario.
Mike Sales
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Re: Evaluating the impact of cycle helmet use...

Post by Mike Sales »

50sbiker wrote: 26 Jun 2021, 10:30am Go scrape your forehead along the road...With and without helmet...Then tell me it makes no difference wearing a helmet.
Do you (or would you) feel less safe cycling without a helmet?
When you feel less safe do you take more care?
Helmets offer, at best, very limited protection, which is easily used up by a belief that they make you safe.
It's the same the whole world over
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Maillot Rouge
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Re: Evaluating the impact of cycle helmet use...

Post by Maillot Rouge »

slowster wrote: 26 Jun 2021, 7:17pm
Maillot Rouge wrote: 26 Jun 2021, 4:26pm You don’t really need science to tell you that in that scenario a helmet would stop your head getting cut or grazed.Common sense tells you that?
You need science to tell you the significance of such a scenario.
No you need common sense.What does science tell you that common sense doesn’t?
It seems that common sense is lacking on both sides of a totally pointless argument!
It seems ‘science’ is the go to argument solver for both for and anti one thing or another.It’s amusing how it changes sides to suit.
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Re: Evaluating the impact of cycle helmet use...

Post by Mike Sales »

Maillot Rouge wrote: 26 Jun 2021, 7:47pm

No you need common sense.What does science tell you that common sense doesn’t?
It seems that common sense is lacking on both sides of a totally pointless argument!
It seems ‘science’ is the go to argument solver for both for and anti one thing or another.It’s amusing how it changes sides to suit.
If common sense was a sufficient guide to reality we would not need science.
Albert Einstein Quotes
Common sense is the collection of prejudices acquired by age eighteen.
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: Evaluating the impact of cycle helmet use...

Post by pjclinch »

Maillot Rouge wrote: 26 Jun 2021, 7:47pm
slowster wrote: 26 Jun 2021, 7:17pm
Maillot Rouge wrote: 26 Jun 2021, 4:26pm You don’t really need science to tell you that in that scenario a helmet would stop your head getting cut or grazed.Common sense tells you that?
You need science to tell you the significance of such a scenario.
No you need common sense.
What is this "common sense" of which you Earth-people speak?
Maillot Rouge wrote:What does science tell you that common sense doesn’t?
It seems that common sense is lacking on both sides of a totally pointless argument!
It seems ‘science’ is the go to argument solver for both for and anti one thing or another.It’s amusing how it changes sides to suit.
Science, done properly, gives you a method and tool set to see if something is right, irrespective of whether it's "obvious". However, the "done properly" bit is a rather huge caveat, and also it's the case that doing science properly will sometimes give an answer along the lines of "it's too complicated to give you an answer with the information we have".

But science does tell you things that "common sense" says are ridiculous, e.g. it's "obvious" that light can't behave as if it were both particles and continuous waves... and yet we have certain proof that it does exactly that.

The reality is that both "common sense" and "science" will be invoked as a reason something must be right, irrespective of whether either are being deployed. The "scrape your head along the road" argument could be stated as either "common sense" or a scientific case-control experiment, but it's actually just a case of not thinking things through any further than confirming one initial prejudices.

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Jdsk
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Re: Evaluating the impact of cycle helmet use...

Post by Jdsk »

It's perfectly possible to have an evidence-based discussion of the many different issues and what's known and what isn't known.

But unfortunately that hasn't been what's happened in the past in this forum.

It's up to us whether that's what happens in the future in this forum.

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Re: Evaluating the impact of cycle helmet use...

Post by drossall »

Maillot Rouge wrote: 26 Jun 2021, 7:47pmWhat does science tell you that common sense doesn’t?
That heavy objects do not in fact fall faster than light ones. That all the "interesting" (i.e. relevant, that you should worry about) things in a collision depend on the square of speed, so 12mph is nearly half as "fast" again as 10mph, and 20mph is four times "faster" and four times more "impact".

That's two for a start that are of some relevance to this topic.
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[XAP]Bob
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Re: Evaluating the impact of cycle helmet use...

Post by [XAP]Bob »

50sbiker wrote: 26 Jun 2021, 10:30am Go scrape your forehead along the road...With and without helmet...Then tell me it makes no difference wearing a helmet.
Great advert for cycling gloves, because all you're trying to protect against is minor scrapes.
I know people who have smashed their entire face in whilst wearing a lid (and they would likely have been much less badly injured if they hadn't been, since it wouldn't have twisted their face into the corner of the car by catching on the roof rail). I have come off my bike a number of times over the years, and the only times I've ever hit a lid were on the garage door.

Neither of those are more than anecdote, but common sense is built on anecdotes, not science. The common sense tells me that my brain knows exactly how big my head is, and is very well designed/adapted to protect the head at that size and mass.

Science tells me that we have survived for many many generations without cycle helmets, even though our travelling speed was much the same (a decent runner, as would all our ancestors have been, can run a 5 minute mile - i.e. sustain 12mph for an hour).
Science tells me that the spec for a lid is based on an impact with a flat surface at 12mph - and no account is made of rotational behaviour (unlike specifications for motorcycle helmets).
Science tells me that a disembodied head (for that is how lids are tested) will hit the ground at just over 13 mph (assuming it falls 1.8m at 9.8m/s^2).
i.e. lids are only designed to protect against a simple fall, one that may result in a big bruise, even a few cuts. They aren't designed to protect against potentially brain injuring collisions, and may even make them worse by converting linear acceleration into rotational acceleration (which the brain, cocooned in its strong bone shell and fluid bath, is much less well able to tolerate).

Social sciences tells us that even the promotion of lids as a safety measure drastically reduces the number of people willing to cycle, but we know that cycling has massive health benefits, outweighing any risk several times over.
We know that walking and cycling result in about the same number of fatalities as each other per mile travelled - yet no-one seems keen on walking helmets.
We know that alcohol consumption massively increases the risk of head injury - yet no-one seems keen on drinking helmets.


NICE statistics show:
https://www.nice.org.uk/guidance/qs74/documents/head-injury-briefing-paper2 wrote:Each year, 1.4 million people attend emergency departments in England and Wales with a recent head injury. Between 33% and 50% of these are children aged under 15 years. Annually, about 200,000 people are admitted to hospital with head injury. Of these, one-fifth have features suggesting skull fracture or have evidence of brain damage. The incidence of death from head injury is low, with as few as 0.2% of all patients attending emergency departments with a head injury dying as a result.
Note that head injury here explicitly excludes face/jaw injuries as convention.

There are only ~4000 cyclists seriously injured each year, and not all of those will be head injuries (I'd say a broken leg is serious for example).
Since it is certain that not all serious injuries are head injuries, and it is also pretty certain that the most serious head injuries will be accompanied by other injuries (how often do we read that a London cyclist was crushed by an HGV, but "they weren't wearing a helmet" - as if that would have done anything at all to change the outcome - I'm going to take a stab in the dark and say that 50% of serious injuries are primarily head injury (I suspect that is a massive over estimate).
Any thought that is put into protecting against head injuries should really be focussed elsewhere - at best you're going to slightly affect 1% of head injuries.

In terms of health interventions - getting people on bikes is far more valuable than any effect that lids could possibly bring.
If we spent half the effort that goes into promoting the least effect possible method of preventing injuries (PPE is always a last resort), on actually making safer cycling routes, legislation that supported active transport, and education on the concept of a public highway then we would make far more difference than plastic ever could.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
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Re: Evaluating the impact of cycle helmet use...

Post by Mike Sales »

[XAP]Bob wrote: 27 Jun 2021, 12:39pm
In terms of health interventions - getting people on bikes is far more valuable than any effect that lids could possibly bring.
If we spent half the effort that goes into promoting the least effect possible method of preventing injuries (PPE is always a last resort), on actually making safer cycling routes, legislation that supported active transport, and education on the concept of a public highway then we would make far more difference than plastic ever could.
We can look at real world "experiments" which attempt to reduce cyclist casualties.
In Australia they tried mandating helmets.
The result was a large drop in miles cycled but no change in cyclist casualty rate, which remains about twice ours.
In the Netherlands a long effort in making safe routes for cycling has produced a casualty rate rather less than half of ours, but many more miles cycled, by all sorts of people, to school or the shops or work, very few of who feel the the need to wear a helmet.

Why are drivers so critical of bare headed cyclists, one wonders.
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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