Helmet fixation distracts from effective safety strategies says US professor

Ush wrote:

Oh, also, I would like to state that I am unequivocally against mandating dried frog pills for anyone and think it should be left to be an individual choice.   Now, back to work filing misleading PR briefs for Headway.

Well, the next time you send your kid in without a dried frog pill, I will confiscate their property and mode of transport. Shoes, cars, whatever. 

Ush wrote:

Homeopathy may have health benefits.  On your next check up Mr. Griff I shall be solicitously enquiring whether or not you have taken your dried frog pills.  You never know, it may help, in addition to the open heart surgery.    Just being reasonable.  Thank you.

No-one has actually demonstrated any harm coming from taking Homeopathic treatments (except for fake news like https://arstechnica.com/science/2016/10/fda-homeopathic-teething-gels-ma... ), so the most sensible course of action is to hedge your bets and take all of the medicines just in case. Personally, I swig down a pint of sea water as that's basically got a tiny bit of everything diluted and I've NEVER died!!!!

alansmurphy wrote:

Across at the park, messing about on a bmx, not so much. Swings and roundabouts...

are best avoided when on the bike

Dagnammit!! There goes my next KickStarter idea.

alansmurphy wrote:

Same as Davel (as we are the same person - hi me) but perhaps a bit harsher.

 

Daughter aged 11 now has a road bike and has a helmet with a built in light. She also has proper shoes, padded shorts, gloves etc. just picks up the helmet as part of her kit. The club rides i do involve helmets so she's one of the gang.

 

Across at the park, messing about on a bmx, not so much. Swings and roundabouts...

 

are best avoided when on the bike

 

I definitely think helmets should be mandated for swings and roundabouts.

Morat wrote:

I'd rather see stats for:

1. Cyclist deaths with Motor Vehicle involved

2. Cyclist deaths without Motor Vehicle involved

Then I think we could make some progress.

This!

You don't stop fingers getting cut in the kitchen with sharp knifes by forcing those who prepare food wear chainmail gloves! You do so by educating those people to use the tool properly and safely and designing the kitchen in a way that makes it safe.

Helmets are not the main cause of injury, they are a distraction, as the article states and as this lengthy discusion proves!

alansmurphy wrote:

Davel, not doubting that you're right here. Do you think the compulsory wearing in events is partly down to insurance though?

Not sure... I don't remember the original reasons BC and British Triathlon etc gave. I know some sportives use the insurance excuse...

But I don't think insurance companies themselves have much truck with mandated helmet wearing? (I recall a debate on here about holiday insurance where one insurer seemed to be going out on a limb by mandating them.)

davel wrote:

alansmurphy wrote:

Davel, not doubting that you're right here. Do you think the compulsory wearing in events is partly down to insurance though?

Not sure... I don't remember the original reasons BC and British Triathlon etc gave. I know some sportives use the insurance excuse... But I don't think insurance companies themselves have much truck with mandated helmet wearing? (I recall a debate on here about holiday insurance where one insurer seemed to be going out on a limb by mandating them.)

Indeed. I was just thinking of the risk assessments etc. that must be a shit load of paperwork. As others have said perception versus reality is a factor. I could quite imangine the insurance, public liability etc. may be significantly different for 2,000 riders versus 2,000 riders with a helmet...

Yorkshire wallet wrote:

If you don't wear a helmet you are literally Hitler

Once upon a time, the application of Godwin's law was enough to end any forum thread... alas these days there is seemingly no killing off of a thread! 

leaderthiever wrote:

My children don't have a choice.  They have to wear a helmet.  When they are older and have become adults they can choose for themselves.

I'm glad I was wearing mine the other day.  One moment I am cycling along, the next I'm lying on the ground after hitting a patch of black ice.  I had hit my head on the road but it was only when I arrived at work and took the helmet off that I realised the damage to the helmet.

I will never know for sure, but kind of thinking I would not be here if I hadn't have been wearing a helmet.

So your helmet failed and by fact of science didn't even absorb close to the maximum in lab reduction of forces which in itself (in best case scenario) isn't even enough to lower those forces to below concussion thresholds. Have you even remotely considered that your head might well have missed the ground completely not wearing a helmet?

It's (not) strange that helmet wearers hit their heads a hell of a lot more often than non wearers and despite the supposed benefits helmet wearing doesn't improve injury rates.

by your logic you should wear a helmet for other activities, walking and driving are two for starters, make sure your kids wear helmets in the car and walking too, both activities proven to be far more likely to cause death by head injury than ALL child cycling deaths in England and Wales.

My child had a choice, he looked to me to offer him advice and guidance, I said f he wanted to he could wear one, I even bought him one, he wore it once, maybe twice then didn't bother, much like his peers.

He cycled to school for 7 years down a 7-8% 60mph limit road and then onto a busy residential road, he started doing that on his own at the age of 10. I now encourage my grandsons to ride and even the older one (at age 9) understands the logic behind not wearing as against wearing a lid as being the safer option and that a helmet increases the chance of a head strike.

Your children are at more risk wearing, children take significantly more risk doing activities when they think they are protected, more so than adults, this is proven time and time again and in multiple peer reviewed studies (google it).

Kids are in the same bracket as those risk takers in the competitive ranks who exhibit the exact same traits and hence why despite all the additional H&S improvements on courses, despite better tyres, better brakes, better handling bikes, crash more, get injured and die more often since helmets were mandated. This also happens on the club run, it happens in weekend warrior riding and in all types of riding to the point that we have clear evidence that helmets have done precisely the sum of nothing to increase safety.

leaderthiever wrote:

My children don't have a choice.  They have to wear a helmet.  When they are older and have become adults they can choose for themselves.

I'm glad I was wearing mine the other day.  One moment I am cycling along, the next I'm lying on the ground after hitting a patch of black ice.  I had hit my head on the road but it was only when I arrived at work and took the helmet off that I realised the damage to the helmet.

I will never know for sure, but kind of thinking I would not be here if I hadn't have been wearing a helmet.

Please allow me to remove your doubt: the helmet didn't save your life.

Helmets are supposed to work by compressing the expanded polystyrene, which absorbs quite a bit of energy, and if they crack or shatter, as yours did, they absorb very little energy; the more energy absorbed, the more protection they provide and yours provided almost none.  To demonstrate the point, take a ceiling tile or some expanded polystyrene packaging, and try to compress it with your fingers; hard isn't it.  Now try snapping it: easy isn't it.

The picture of your helmet shows no sign of compression deformation, it has simply snapped, and thus provided very little protection.  Experts in helmets have examined hundreds of them involved in collisions and found no evidence of compression, and there are thousands of pictures like yours on the web, all showing clearly that helmets don't work as intended, they fail catastrophically instead.

All neatly summed up here http://www.cyclehelmets.org/1209.html

burtthebike wrote:

Please allow me to remove your doubt: the helmet didn't save your life.

Helmets are supposed to work by compressing the expanded polystyrene, which absorbs quite a bit of energy, and if they crack or shatter, as yours did, they absorb very little energy; the more energy absorbed, the more protection they provide and yours provided almost none.  To demonstrate the point, take a ceiling tile or some expanded polystyrene packaging, and try to compress it with your fingers; hard isn't it.  Now try snapping it: easy isn't it.

The picture of your helmet shows no sign of compression deformation, it has simply snapped, and thus provided very little protection.  Experts in helmets have examined hundreds of them involved in collisions and found no evidence of compression, and there are thousands of pictures like yours on the web, all showing clearly that helmets don't work as intended, they fail catastrophically instead.

All neatly summed up here http://www.cyclehelmets.org/1209.html

So the compression of the polystyrene is the only way in which helmets work?

No.

There is also energy dissipation.

A small force collision with a small area (eg a rock or the edge of a kerb) will produce very high levels of pressure at the point of impact, this can easily cause a skull fracture and a brain injury. If the force of collision is dissipated over a larger area by a helmet then the pressure becomes much reduced along with the likelihood of a skull fracture.

So a cracked helmet doesn't prove that the helmet hasn't worked at all.

It's absolutely impossible to tell this from just a picture, your certainty is merely a reflection of your own bias.

Rich_cb wrote:

burtthebike wrote:

Please allow me to remove your doubt: the helmet didn't save your life.

Helmets are supposed to work by compressing the expanded polystyrene, which absorbs quite a bit of energy, and if they crack or shatter, as yours did, they absorb very little energy; the more energy absorbed, the more protection they provide and yours provided almost none.  To demonstrate the point, take a ceiling tile or some expanded polystyrene packaging, and try to compress it with your fingers; hard isn't it.  Now try snapping it: easy isn't it.

The picture of your helmet shows no sign of compression deformation, it has simply snapped, and thus provided very little protection.  Experts in helmets have examined hundreds of them involved in collisions and found no evidence of compression, and there are thousands of pictures like yours on the web, all showing clearly that helmets don't work as intended, they fail catastrophically instead.

All neatly summed up here http://www.cyclehelmets.org/1209.html

So the compression of the polystyrene is the only way in which helmets work? No. There is also energy dissipation. A small force collision with a small area (eg a rock or the edge of a kerb) will produce very high levels of pressure at the point of impact, this can easily cause a skull fracture and a brain injury. If the force of collision is dissipated over a larger area by a helmet then the pressure becomes much reduced along with the likelihood of a skull fracture. So a cracked helmet doesn't prove that the helmet hasn't worked at all. It's absolutely impossible to tell this from just a picture, your certainty is merely a reflection of your own bias.

Surely basic physics means the energy is  going to go somewhere?  It's not 'dissipated' into nothing (what's the definiton of 'dissipated', in this context, by the way?  Where is the energy 'dissipated' to?).

I would have thought it would largely go into rattling your brain around inside your skull, which still seems rather unpleasant.  But I expect the helmet would mean less of it went into direct abration and localised impact on a part of the scalp and skull...though what the helmet breaking says about that is entirely non-obvious.

The previous poster does indeed display too much certainty, but I think its understandable in the face of yet another 'look at what happened to this helmet, it's obvious it helped change the outcome' post.  He can't know it _didn't_ help, purely because it broke, but excessive certainty begats excessive certainty.

The central point is a valid one - a helmet breaking doesn't prove it "absorbed" more energy, nor that it 'dissipated' it.  I can't imagine a bit of plastic snapping emits much heat energy or noise, so how oculd it 'absorb' more energy?  Where did it go?  Some sort of elastic compression spreading out the transmission of that energy over a few microseconds?  It seems a very long way from 'obvious' what it all means.

All one can rationally do is look at that picture and think 'and?  what am I supposed to conclude from that?'  Where's the detailed physical analysis?

FluffyKittenofTindalos wrote:

Surely basic physics means the energy is  going to go somewhere?  It's not 'dissipated' into nothing (what's the definiton of 'dissipated', in this context, by the way?  Where is the energy 'dissipated' to?).

I would have thought it would largely go into rattling your brain around inside your skull, which still seems rather unpleasant.  But I expect the helmet would mean less of it went into direct abration and localised impact on a part of the scalp and skull...though what the helmet breaking says about that is entirely non-obvious.

 

The previous poster does indeed display too much certainty, but I think its understandable in the face of yet another 'look at what happened to this helmet, it's obvious it helped change the outcome' post.  He can't know it _didn't_ help, purely because it broke, but excessive certainty begats excessive certainty.

 

The central point is a valid one - a helmet breaking doesn't prove it "absorbed" more energy, nor that it 'dissipated' it.  I can't imagine a bit of plastic snapping emits much heat energy or noise, so how oculd it 'absorb' more energy?  Where did it go?  Some sort of elastic compression spreading out the transmission of that energy over a few microseconds?  It seems a very long way from 'obvious' what it all means.

All one can rationally do is look at that picture and think 'and?  what am I supposed to conclude from that?'  Where's the detailed physical analysis?

The energy is still mostly transferred to the head with a small amount being absorbed by the cracking of the helmet.

The crucial point is the surface area. As the impact is transmitted through the helmet the surface area that the impact is spread over is greatly increased.

By spreading the force/energy in this way the likelihood of a skull fracture is reduced.

You can't prove anything by looking at a picture of a broken helmet. A large crack could indicate that the helmet has hit a sharp rock and successfully spread the energy over a large area avoiding any injury. It could also mean the helmet simply failed.

The well worn argument that 'unless you see compression of the polystyrene the helmet has done nothing' is obviously flawed.

FluffyKittenofTindalos wrote:

 

Surely basic physics means the energy is  going to go somewhere?  It's not 'dissipated' into nothing (what's the definiton of 'dissipated', in this context, by the way?  Where is the energy 'dissipated' to?).

I would have thought it would largely go into rattling your brain around inside your skull, which still seems rather unpleasant.  But I expect the helmet would mean less of it went into direct abration and localised impact on a part of the scalp and skull...though what the helmet breaking says about that is entirely non-obvious.

In an ideal World, it is as you suggest, the impact energy is converted to heat, but don't expect your helmet to become too hot to handle. Arresting a 2.5kg head from 30mph releases 211Joules, which will only heat up your 300g helmet by 0.5C.  

Burtthebike is possibly correct. It is not easy to see from the photographs, but if the helmet broke due to a large area impact, which is what cycle helmets are designed to protect against, there would be some sign of  permanent deformation of the foam. Breaking foam, due to applying an uneven load, does not take much force, and therefore does not absorb much energy.