Crash and helmet

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Mike Sales
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Re: Crash and helmet

Post by Mike Sales »

Nearholmer wrote: 14 Aug 2022, 10:40am There’s a large body of academic literature, supported I would suggest by common-sense observation, which suggests that societal tolerance of avoidable risk is closely related to the level of un-avoidable risk present in that society.

So, if un-avoidable risk, from things like infant mortality, war, incurable disease, punishing physical work, poor sanitation etc, falls, as it has in our society over the past many years, then our societal appetite for avoidable risks, accidents at work, accidents on the road, self-harm through smoking, excessive alcohol etc, also falls. It’s as if we don’t accept avoidable risk poking its head above the background of unavoidable risk.

That I think explains a lot of the difference between attitudes now and even as recently as the 1960s and 1970s, because then unavoidable risks were still reaping a much greater toll than they do now, as visible through the much lower average life expectancy.

You only have to visit a “developing country”, where un-avoidable risk is much higher than in Western Europe to see this in action.

Herein lies part of the cause of a lot of grumpy old men complaining about modern ‘snowflakes’: societal risk appetite changed, and the grumpy old men still have their personal risk appetites calibrated to the halcyon days of their youth. I think Pliny the Elder noted ‘calibration differences’ causing friction between old and young in about AD60, so it’s not a new phenomenon.
Are the roads really safer now? Is it only a change in my attitude to risk which makes me feel so much more endangered on the same roads that I rode to school on?
Why is the large number of road deaths still tolerated? By the standards of other transport modes it is huge.
Last edited by Mike Sales on 14 Aug 2022, 10:53am, edited 1 time in total.
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?
Mike Sales
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Re: Crash and helmet

Post by Mike Sales »

ed.lazda wrote: 14 Aug 2022, 10:42am

There is reasonable evidence that compelling cyclists to wear helmets is a very poor public health measure, and there is no justification for it.

Conclusions? In my opinion individual cyclists should be free to wear helmets or not, as they please. There is no justification for cycling clubs, event organisers or governments to enforce helmet wearing. There is no place for anyone to persuade another that they should or shouldn't wear a helmet, especially if that opinion is based on anecdote and/or opinion unsupported by evidence.

While not wanting to stifle discussion, is there any point in debating this any further unless significant new evidence appears?
I quite agree. If those trying to get me to wear a helmet would keep quiet I would not be posting here now.
In the unlikely event I get fit enough to join club runs or organised events again I would not be allowed to.
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?
Jdsk
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Re: Crash and helmet

Post by Jdsk »

ed.lazda wrote: 14 Aug 2022, 10:42amWhile not wanting to stifle discussion, is there any point in debating this any further unless significant new evidence appears?
There's plenty of evidence out there for anyone who:
1 Wants to follow evidence-based methods (which don't include cherry-picking, whataboutery, anecdote, ad hominem and straw man argument, or dogma).
2 Is prepared to ask and answer and stick to discussing specific questions on the subject rather than jumping between different questions.

The problem in this forum is agreeing the ground rules of the discussion, not the absence of evidence.

Jonathan
Nearholmer
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Re: Crash and helmet

Post by Nearholmer »

Are the roads really safer now?
Depends a lot what you mean by the question.

Fewer people get killed on roads now than in the 1960s by a long chalk, and if you factor-in the increase in motor vehicle miles driven the reduction in deaths/mile is even steeper.
14E59076-02C0-4A76-99CE-4444C5FFFB5B.jpeg
But, over the same period ‘vulnerable road users’ have been decisively driven off many roads, so if their/our judgements of when it is too dangerous to use the roads is the criterion, the roads have become more, not less, dangerous.

But, back to my societal risk appetite point: society very definitely had an appetite to reduce road deaths, which it perceived as avoidable, and that has been achieved By a complex blend of measures.
Nearholmer
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Re: Crash and helmet

Post by Nearholmer »

Why is the large number of road deaths still tolerated? By the standards of other transport modes it is huge.
Why?

Perceived costs vs perceived benefits.

Society overall perceives that the balance between deaths, injuries, land-take, pollutions of multiple kinds etc, the benefits that it accrues from road motor transport, and the potential costs of reducing the harms is “about right”.

We might individually feel that the balance is anything but right, but unless or until that coalesces into a widespread discontent with the current balance (as it did with road deaths in the mid-1960s), the balance will rest roughly where it is now.

Personally, I do perceive some tiny shifting of the balance of opinion in some places, driven by a combination of sustainability and ‘livability’ concerns among mostly younger people (those with long term ‘skin in the game’), but it doesn’t feel anything like decisive yet: the vast majority of people, young and old alike, hugely value the perceived benefits of road motor transport, and only very rarely consider the harms.
Last edited by Nearholmer on 14 Aug 2022, 11:39am, edited 1 time in total.
Mike Sales
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Re: Crash and helmet

Post by Mike Sales »

Nearholmer wrote: 14 Aug 2022, 11:20am
Are the roads really safer now?
Depends a lot what you mean by the question.

Fewer people get killed on roads now than in the 1960s by a long chalk, and if you factor-in the increase in motor vehicle miles driven the reduction in deaths/mile is even steeper.
I want to cycle as much as I can, and it is generally agreed that more cycling by everybody would be a good thing for society. So I am asking whether cycling is safer. I don't think so, and it is annoying to be told that we have the safest roads in Europe or whatever.
that has been achieved By a complex blend of measures.

These include better, faster medical help, cars which protect those inside (but do little for those outside,) so that insurance takes care of the damage, without killing,. and. as you say, scaring the vulnerable off the road, and those remaining having to take much more care.
I do not like the roads being turned into a sort of dodgems circuit. Many of these increased miles a driven on roads on which the vulnerable road user is not allowed. The remaing miles, on shared roads may well be much worse per mile for us.
It's interesting that motors get special roads to high design standards, whereas the facilities for cyclists are poor, erratic and highly variable.
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?
Nearholmer
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Joined: 26 Mar 2022, 7:13am

Re: Crash and helmet

Post by Nearholmer »

Being brutally frank about it, what you or I would like, which are probably very similar things, doesn’t matter a jot unless a critical-mass of our fellow citizens feel the same, and right now they don’t.

People value road motor transport very highly: they value the way it enables relatively low-cost shopping through cut-throat competition in logistics; and, they value the convenience, weather-proofness etc of cars for personal transport.

And, it’s all particularly tight knot to cut, because since about the mid-late 1950s our entire society, the physical and mental fabric of life, has become totally entwined with road motor transport. We are in a symbiosis with cars and lorries, and unpicking that and re-stitching it differently would be a monster job, the first step of which is to have the will to do it.

There are odd places where it is genuinely happening, in a sort-of exploratory way, but not many, Cambridge being one. Interesting that it is a place with a younger and far better educated population than most which is trying it.
Mike Sales
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Re: Crash and helmet

Post by Mike Sales »

Nearholmer wrote: 14 Aug 2022, 11:36am
Why is the large number of road deaths still tolerated? By the standards of other transport modes it is huge.
Why?

Perceived costs vs perceived benefits.

Society overall perceives that the balance between deaths, injuries, land-take, pollutions of multiple kinds etc, the benefits that it accrues from road motor transport, and the potential costs of reducing the harms is “about right”.

We might individually feel that the balance is anything but right, but unless or until that coalesces into a widespread discontent with the current balance (as it did with road deaths in the mid-1960s), the balance will rest roughly where it is now.

Personally, I do perceive some tiny shifting of the balance of opinion in some places, driven by a combination of sustainability and ‘livability’ concerns among mostly younger people (those with long term ‘skin in the game’), but it doesn’t feel anything like decisive yet: the vast majority of people, young and old alike, hugely value the perceived benefits of road motor transport, and only very rarely consider the harms.
The problems of mass motorisation, and the benefits of using other modes are a commonplace in discussions of transport policy.
When it comes to making personal decisions about transport, the equation is different. Should I get a car, though it is expensive and environmentally undesirable, or should I deprive myself of the benefits of car ownership, which would make no measurable contribution to improving the environment, but be a big deprivation for me?
It is much harder to change public policy than to change personal policy, but car ownership should not be taken as a vote for the status quo.
I hope you are right that things are changing. Another consideration is affordability. The cost of fuel makes a difference, and should help make car owning less attractive, and so may congestion.

Edited to add.
Your last post makes similar points to mine. Yes, it will be difficult.
Was in bankruptcy about which somebody said, "it happens slowly at first, and then very quickly."?
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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Cugel
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Re: Crash and helmet

Post by Cugel »

When I am dictator, any time now, I will insist on every subject behaving coherently, even if they wish to adopt daft but pointless behaviours. For example, those judging the tiny risk of serious head damage from cycling and so choosing to wear a helmet (even though the protection offered is very small indeed) will be required to wear similar hats when they perform a range of everyday behaviours that have a similar or greater risk of head-bangs.

This will probably mean that they'll all have to wear a helmet all the time. Even when asleep in bed, it's possible to fall out and get a serious head-bang, so helmets in bed it is then!

Of course, there's major risk in getting a head injury when travelling in a car. I'm surprised that the helmet manufacturers haven't come up with more product for that vast untapped market! Then there's the risk of a serious head bang when traversing the stairs - another vast market, inclusive of the helmet hooks at both the top and the bottom of the stairs. And probably at least two helmets per person per household, so you never find yourself downstairs with the helmet up stairs. Think of the risk of going up there hatless to get it!

Lastly, we must correct the situation with the current cycling helmets for those feeling they are essential to their head-welfare. They'll actually have to work to protect all of your head in every cycling head-bang situation. This will mean they'll weigh 5X as much and cost 10X as much. Also, there'll be the cost of the shoulder and neck braces to stop your head sinking down under the helmet weight so you can't raise it to see the accidents coming, thick & fast.

Cugel, just extrapolating some daftness to even more daft.
“Practical men who believe themselves to be quite exempt from any intellectual influence are usually the slaves of some defunct economist”.
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ed.lazda
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Re: Crash and helmet

Post by ed.lazda »

Cugel wrote: 14 Aug 2022, 12:48pm Cugel, just extrapolating some daftness to even more daft.
You think you jest. you can buy these on Amazon. "Thudguard -- learning to walk in a world of hard surfaces." :D :D

thud.png
Stevek76
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Re: Crash and helmet

Post by Stevek76 »

50sbiker wrote: 13 Aug 2022, 6:12pm The idea that the thickness of the helmet makes the difference between contact and non-contact is nuts.
Can make a huge difference depending on an individuals proportions. I'm relatively broad shouldered and don't have a particularly long neck. If I land on my side on flat ground it is physically impossible for my head to hit the ground unless my neck breaks (which is not happening for the speeds involved in a lowsider*). The additional 2-4cm of a helmet does bring me into that range. The analogy with leathers doesn't work because leathers are there to protect the bits of the body that generally hit first and have nothing to stop them doing otherwise.

*Said speeds also the reason the OPs talk about not being here had they not been wearing one are rather hyperbolic. There's a tendency to forget about the directionality of forces when considering crashes, unless there is a moment to convert your horizontal velocity into downwards velocity, that horizontal velocity is largely only relevant for road rash considerations, the vertical impact of your head against the tarmac will be only dependent on the starting height of the fall. There are significant evolutionary pressures for the skull to be tough enough to take that sort of fall from head height without serious injury or death.
Mike Sales wrote: 14 Aug 2022, 11:38am
Nearholmer wrote: 14 Aug 2022, 11:20am
Are the roads really safer now?
Depends a lot what you mean by the question.

Fewer people get killed on roads now than in the 1960s by a long chalk, and if you factor-in the increase in motor vehicle miles driven the reduction in deaths/mile is even steeper.
So I am asking whether cycling is safer. I don't think so, and it is annoying to be told that we have the safest roads in Europe or whatever.
.

Cycling is safer, per distance travelled but probably feels less safe due to the fact that most roads are now motor traffic sewers, cars are much larger and parked everywhere and anywhere due to a 3-4x increase in case ownership. It is not the safest in Europe and i don't recall seeing the claim anywhere. That said, the Netherlands cyclist fatality rate per distance isn't actually that much lower at about 1/3rd per distance cycled of GB, though that is up on previous years largely due to old men killing themselves on ebikes. Can't recall how injury rates compare, there may be a larger difference there.
The contents of this post, unless otherwise stated, are opinions of the author and may actually be complete codswallop
drossall
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Re: Crash and helmet

Post by drossall »


DevonDamo wrote:However if you think these arguments apply to colliding with a solid object on a downhill fall with sufficient force to break a helmet in two, then our paradigms are so divergent that we're probably better off settling this via that most respected of all scientific methods
I don't believe that I referenced "those arguments", and I did say that the helmet could have provided some benefit. Indeed, in a direct impact of the type described, I'd probably prefer to be wearing one. But accidents are mysterious things, and people come unscathed out of horrendous crashes, whilst others get life-changing injuries from the most innocuous events. So outcomes from individual ones only tell us so much. The key thing is that a smashed helmet has failed in a manner that does not necessarily reflect impact absorption in the intended manner.

The point about "those arguments", since you've introduced them, is that,in the real world, you can't know in advance that your crash will be a direct impact, so you have to decide with that in mind. Personally, I don't ride MTBs at speed downhill, so I'm not sure what I'd do.


drossall
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Re: Crash and helmet

Post by drossall »


50sbiker wrote:The idea that the thickness of the helmet makes the difference between contact and non-contact is nuts.
I'm not sure, but I'm reminded, every time I go through a doorway with a phone or other small item on my belt, how easily our amazing ability to judge our own size can be upset. I catch myself on the frame so often.

Now, in a crash, our ability to judge and respond to anything is in doubt, but I've watched riders tuck and roll in at least one TdF crash where I did think precisely that the helmet was going to make the difference over a head impact or none.

Warning - that was anecdote of the worst kind... I'm not sure how you'd collate evidence on this.


Stevek76
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Re: Crash and helmet

Post by Stevek76 »

drossall wrote: 14 Aug 2022, 1:42pm Personally, I don't ride MTBs at speed downhill, so I'm not sure what I'd do.
Entirely anecdotally, mtbing is the only time i use a helmet and when i exhibit fairly extreme risk compensation as a result of that. Indeed partly the reason i wear that plus gloves and often wrist guards is the confidence that provides to push myself to try out stuff that is closer to my limit of ability.

When it's very hot i may do my local trails for a bit of exercise without a helmet and simply tone it down a bit.
mjr wrote: 14 Aug 2022, 12:31am Until you remember that all except a few full face MTB helmets are only tested for standing falls onto flat surfaces or kerb edges.
However the independent testing done by groups like folksam and virginia tech do indicate that most mtb helmets tend to do far better than the minimum requirements. A better standard testing process though would be very useful for actual more extreme sports cycling uses as it is otherwise not obvious for consumers to see which helmets have actually valued protective capabilities and which have simply minimised that to max out aero/ventilation/weight etc.
The contents of this post, unless otherwise stated, are opinions of the author and may actually be complete codswallop
Nearholmer
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Re: Crash and helmet

Post by Nearholmer »

What causes the head (or anything else come to that) to get injured in an accident (or a deliberate attempt to injure) is kinetic energy being dissipated very suddenly, so when making “interesting” comparisons between things like falling out of bed and coming off a bike, it’s important to think about the energies involved.

But, it isn’t easy to think about that, because, apart perhaps from aristos in the French Revolution, most incidents don’t involve a detached head, free-falling or banging into something, a lot else is going on. Either other bits of the body are acting to slow down (that is reduce the kinetic energy at) the head, or, in something like an un-impeded head-first free fall then more mass than its own it “carried” by the head, increasing the kinetic energy dissipated through it.

Nevertheless, we can get some comparative, if not absolute, idea of what is going on by considering a 5kg head in isolation, and thinking about free fall height and impact speed on fixed object.

Free fall from 1m (bed?) is roughly 10mph, dissipating 49 Joules.

Free fall from 2m (passing out and hitting the floor/pavement?) is roughly 15mph, dissipating 98 Joules.

Free fall from 4m (some really nasty stair falls?) is roughly 20mph, dissipating 196 joules.

Free fall from 6m (upstairs window?) is roughly 25mph, dissipating 294 Joules.

All that energy has to get dissipated somehow, by deforming, and possibly fracturing, the skull, and through deformation of the squishy stuff inside it, as heat, and a bit of sound.

Now, the exact nature of the impact comes into it too, because in a free-fall or ‘direct on’ impact the time over which energy is dissipated is very short indeed (not quite instantaneous though, because the squishy stuff inside takes time to squish), whereas in a sliding or glancing impact the dissipation time will be greater, which, importantly, will alter the deceleration rate of the squishy stuff, and perhaps alter how it is moving within the shell of the skull. And, if the impact is onto a sharp edge or point, rather than a flat surface, the skull may get penetrated, and a whole new set of injury types may occur - poleaxing, or battle-axing injuries.

Why mention all this? Because at higher, but perfectly feasible when cycling, speeds of impact, the energies involved move from those typically involved in events that humans seem to survive not too badly, to those involved in very nasty accidents and deliberate attempt to kill.

The probability of being involved in one of the higher energy events, even for a person who cycles a great deal, is low, but I would strongly suggest that the consequences may be very nasty indeed. And, which class of incidents causes immense amounts of head-scratching, and often bitter argument, when it comes to deciding what, if any, mitigating measures to apply? Low probability, high consequence ones, and where it is a matter of individual choice how to react to such a risk, a third of people will focus only on probability, a third only on consequence, and a third will attempt to factor the two together.
Last edited by Nearholmer on 14 Aug 2022, 3:00pm, edited 2 times in total.
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