Research into helmet compulsion

[byegad]

A motorcycle helmet is also a polystyrene hat ...

But built to a much higher specifications and a lot heavier. I wouldn't pedal in a motorcycle helmet for any amount of money.

 

[CopperBrompton]

Nor me, but the 'polystyrene hat' label seems to me to be used in a dismissive way. The reality is that polystyrene is an excellent material for protecting your brain, because it crushes progressively and thus slows your brain gently.

Polystyrene is one of the best materials in the world for preventing or lessening brain injury, which is why it is used in motorcycle helmets and F1 helmets.

 

[MartinC]

Granted, if you broke a leg a helmet would not have helped, or if the car ran over your skull.

The wearing of a helmet is to mitigate head injuries, so the case has to be one involving a head injury where 'on the balance of probabilities' a helmet would have had an effect on the outcome.

If the insurers persuade the court 51% to 49% that a helmet would have reduced the injury then you lose.

Each case turns on its own merits, that's why legal teams have a right of rebuttal when a previous judgment is used as a precedent in any case brought.

I'm talking about Smith vs. Finch (2009) where the cyclist suffered serious head injuries. The judge ruled that because the victim had hit the ground at more than 12mph no helmet could've prevented or mitigated the injury.

Yes, insurance companies will always try it on. They haven't won a case yet. If they want to they need to find credible expert witnesses who can make a sound case that a cycling helmet could've mitigated the injury. Despite having the financial motivation and resources to find these (if they exist) they haven't been able to. Draw your own conclusions.

 

[CopperBrompton]

Which is a bizarre basis for the ruling. Helmets are not 100% effective at 12.00mph and 0% effective at 12.01mph - they become progressively less effective the higher the impact speed.

At typical cycling speeds, you will almost always be better off with a helmet than without one (and yes, I'm aware of the torsional neck injury argument, but in most cases a helmet skin is slippier than a skull, so torsional injuries will occur with or without a helmet and logic would suggest they are more common without).

 

[Dan B]

FWIW, 13mph is the speed at which you'd hit the ground in a fall from 2 metres. Obviously this assumes you'd fall straight over and not use an outstretched limb or twist to break your fall (quite hard to do, usually), and there's a whole discussion we're not having about the difference between the speed you're moving at before the accident and the actual speed of contact with the ground, but this does indicate that pedestrians may well "use" a cycle helmet at up to its design limit.

 

[very-near]

I'm talking about Smith vs. Finch (2009) where the cyclist suffered serious head injuries. The judge ruled that because the victim had hit the ground at more than 12mph no helmet could've prevented or mitigated the injury.

Yes, insurance companies will always try it on. They haven't won a case yet. If they want to they need to find credible expert witnesses who can make a sound case that a cycling helmet could've mitigated the injury. Despite having the financial motivation and resources to find these (if they exist) they haven't been able to. Draw your own conclusions.

I can show you the lid, and you can meet the wearer (he lives in Leckhampton) for first hand testimony if you have any doubt as to the effectiveness of crash helmets in an impact which was considerably higher than 12mph.

I would be interested to know if styrene thickness on a cycle hat is a great deal thinner or less dense/more dense than that used in m/cycling hats.

What I don't really like about cycle hats is the leaning in design aesthetics towards swoopy lumps and bumps on them.

They have managed to make m/cycle crash helmets look good without resorting to useless styling features so why not for cycling hats ?

 

[CopperBrompton]

My biggest accident was downhill at 25-30mph.

I was young and foolish, and thought it a good idea to bomb between two lanes of slow-moving traffic. The inevitable happened and someone changed lanes in front of me. I hit their front wing, completely cleared their bonnet and head-butted the road. The impact speed was certainly well above 12mph.

The helmet did its job of absorbing impact by crushing. It ended up with barely more than the thickness of the shell. I had a slight concussion.

I would not have liked to have attempted those aerobatics without a helmet.

So yes, highly effective up to 12mph and progressively less effective at higher speeds, but far from useless.

 

[HJ]

Time to bring in an expert witness...

When considering the gain to be achieved through the wearing of cycle helmets, real-world evidence of performance is a key factor. But it is also important to keep head injury when cycling in perspective.

Road cyclists account for less than 1% of the people admitted to British hospitals with head injuries. Other road users suffer many more head injuries than cyclists, and still more occur in the home and at work.

Cyclists, on average, live up to 10 years longer than non-cyclists with healthier lives, which cannot mean that they are specially at risk.

It takes 8,000 years of average cycling to produce one clinically severe head injury, let alone one that might be mitigated by a helmet.

From Cycle Helmet Performance in the Real World. John Franklin,
Consultant in Cycling Skills and Safety, Cheltenham. A presentation to the Gloucestershire Accident Action Group, 24th June 2002.

 

[Greenbank]

Many problems in helmet debates are caused by one of several assumptions (i'll start with just two):-

a) Just because someone wearing a helmet survived an accident does not mean that they would have died if they were not wearing one. No matter how much damage was done to the helmet you simply don't know what would have happened.

Just because someone died not wearing a helmet does not mean that they would have survived if they were wearing one.

I stop reading when someone starts with the "He would have definitely died had he not been wearing one" line. It's not debate, it's opinion stated as fact.

Again, I'm pro-choice. I'm not anti-helmet.

 

[gdean]

Nice video here:

View: http://vimeo.com/4381805

 

[CopperBrompton]

I think I am not that average cyclist, as I've managed to headbutt the road three times in 41 years. :-)

But I agree with the broader point. While I personally think helmets make sense (and modern ones are light enough and cool enough that I see no downside), cycling remains a very safe activity. I also fully support freedom of choice on helmets.

 

[Greenbank]

Which is a bizarre basis for the ruling. Helmets are not 100% effective at 12.00mph and 0% effective at 12.01mph - they become progressively less effective the higher the impact speed.

Exactly, but it goes to show that there are uninformed/stupid people on both sides of the debate.

 

[bonj2]

What i can't get my head round with this 12mph thing, is does that refer to the speed you are travelling along at when you crash, or the speed with which your head hits the ground?
Because the two could be very different.
Or is it assumed that they are not? And if so is this a valid assumption?

 

[CopperBrompton]

Indeed. It is unfortunately one of those debates that tends to polarise people, and I really should know better by now than to engage in one. :-)

Where I think the vast majority of us on both sides of the debate can agree is that the choice should be down to the individual.

Ben, pro-choice helmet-wearer

 

[MartinC]

Which is a bizarre basis for the ruling. Helmets are not 100% effective at 12.00mph and 0% effective at 12.01mph - they become progressively less effective the higher the impact speed.

At typical cycling speeds, you will almost always be better off with a helmet than without one (and yes, I'm aware of the torsional neck injury argument, but in most cases a helmet skin is slippier than a skull, so torsional injuries will occur with or without a helmet and logic would suggest they are more common without).

These are both assumptions. In court you'd have to justify them.

Bear in mind that the effectiveness (I assume you're defining it as energy absorption) doesn't vary linearly. If you subject the helmet to enough force it will break up. In these circumstances the amount of energy it absorped before it broke is a total unknown and could even be close to zero. So at some impact speed the helmet performance may drop off markedly creating the "bizarre" circumstance you describe.

Your second point is an assertion presumably based, I guess, on intuition and common sense. A typical cycling speed is probably between 8mph and 30mph. This quite challenging for helmet engineering. You also need to define what you mean by better off (less dead? no grazes?). In the court scenario this would have to be quantifiable and substantive

The potential effect of a helmet on torsional injuries is derived much more from the effective increase (and thus increase in torque applied by a glancing blow) in head diameter than in differences in friction.

There's also a big Catch 22 in all of this. The vast majority of cases that come to court will be off the back of traffic accidents where a motor vehicle was involved. Since it's generally accepted that helmets can't be effective in accidents involving other vehicles it seems unlikely that anyone would ever make the case for contributory negligence.