Research into helmet compulsion

[semislickstick]

I think the 12mph drop kerb test is the European standard. (minimum) Some helmet's are tested beyond this, some a lot better than others, the old ANSI standard is a higher rated standard isn't it?
The testing could do with an update I reckon!
Just cos one years make and model saved you at 20-25mph doesn't mean they all will or even the next years slightly changed model will.
I don't think they test for how badly the extra width on your head will be damaging to your neck on impact or the pointy, slightly aero design do they? I've been wondering whether the skate style helmets(that meet the cycle standard) are better....with a chin guard!

 

[CopperBrompton]

Actually, the relationship between the degree of crushing and the amount of force absorbed is measurable, so we could indeed tell how much force was absorbed prior to a helmet breaking.

Better off = sufficient force absorbed to achieve any of the following:
- turning a fatal impact into a surviveable one
- turning a severe brain injury into a lesser one
- turning a minor brain injury into no brain injury

A helmet does increase the diamete of the head, but helmet skins are required to be slippery precisely to increase the chances of the head sliding rather than grabbing and rotating. Scalps are not slippery.

Helmets will be ineffective in *some* accidents involving motor vehicles, and effective in others. Just as in accidents not involving motor vehicles.

 

[Dan B]

I've been wondering whether the skate style helmets(that meet the cycle standard) are better....with a chin guard!

Not at 12mph, no. Your head will overheat

Speedskaters almost invariably wear cycle helmets instead, for exactly that reason

 

[summerdays]

The first thing you will be asked if you're knocked down and you’re still conscious and hopefully you will be is "Have you hit your head?" The emergency services ask this as the brain is the most important muscle in your body and any impact to it can be potentially serious. That's what they asked me when I was knocked downin 1999. Fortunately I was wearing a helmet. They still did checks on my head to see if I was concussed having hit the road. Once satisfied I was not they attended to my other injuries.

In my last accident they asked the same question which seemed a bit pointless as that was all they did. Other than asking if anywhere other than my arm hurt at no point did they appear to check head. As it was I hadn't hurt it - but there was no point asking the question other than finding out that I had been wearing one.

 

[col]

For those times when an impact is on the helmet, it will save some, even if its a minority of all the types of impacts out there.

 

[Dan B]

I was asked that question on Wednesday night too, after a fall from (I estimate) about 15mph. Answer "yes", but knees and elbows absorbed most of the force first

 

[CopperBrompton]

Nice video here:

View: http://vimeo.com/4381805

Excellent stuff. Have cycled a few times in Amsterdam, and always enjoyed it. It's a bit of a slower pace than London, but very pleasant.

 

[very-near]

Actually, the relationship between the degree of crushing and the amount of force absorbed is measurable, so we could indeed tell how much force was absorbed prior to a helmet breaking.

Better off = sufficient force absorbed to achieve any of the following:
- turning a fatal impact into a surviveable one
- turning a severe brain injury into a lesser one
- turning a minor brain injury into no brain injury

A helmet does increase the diamete of the head, but helmet skins are required to be slippery precisely to increase the chances of the head sliding rather than grabbing and rotating. Scalps are not slippery.

Helmets will be ineffective in *some* accidents involving motor vehicles, and effective in others. Just as in accidents not involving motor vehicles.

A sensible summary.

 

[MartinC]

Actually, the relationship between the degree of crushing and the amount of force absorbed is measurable, so we could indeed tell how much force was absorbed prior to a helmet breaking.

Better off = sufficient force absorbed to achieve any of the following:
- turning a fatal impact into a surviveable one
- turning a severe brain injury into a lesser one
- turning a minor brain injury into no brain injury

A helmet does increase the diamete of the head, but helmet skins are required to be slippery precisely to increase the chances of the head sliding rather than grabbing and rotating. Scalps are not slippery.

Helmets will be ineffective in *some* accidents involving motor vehicles, and effective in others. Just as in accidents not involving motor vehicles.

OK. Not trying to be confrontational but just trying to apply som rigour to the arguments.

If you were in the Smith vs. Finch case appearing as an expert witness for the insurance company and presented the above the questions you would get are:

You've measured the amount of energy the helmet absorped. Can you tell us the energy required to produce the head injury in question and is the amount saved relevant?

In the "better off" scenarios you describe can you tell us the amount of force reduction required to achieve each of these - either generically or for this particular set of circumstances.

Helmets don't increase the size of the head but the laws of physics show that they allow a force to be applied to the head with a larger moment. Yes or no?

So you believe that helmets can be effective in some accidents with motor vehicles. Tell us what the differentiating factors are are how they apply to this accident.

Without the answers it's speculation.

 

[Greenbank]

A helmet does increase the diamete of the head, but helmet skins are required to be slippery precisely to increase the chances of the head sliding rather than grabbing and rotating. Scalps are not slippery.

As MartinC above says, it's not just the friction. The increased diameter increases the chance of an impact, it also increases the chance of the head grabbing and rotating.

 

[CopperBrompton]

None of us are in a position to 'apply rigour' to the facts of that particular case, because we're not privy to them.

What we can do is look at the general factors.

So far as I can see, nobody disputes that helmets sometimes help and sometimes don't. The arguments relate to the proportion of each case, and we're all speculating there.

 

[col]

As MartinC above says, it's not just the friction. The increased diameter increases the chance of an impact, it also increases the chance of the head grabbing and rotating.

But isnt the head with its skin or hair more grippy than smooth plastic? And the number of times the extra two inches of diameter the helmet actually gives contributes to injury, is less or more than not wearing it at all?

 

[very-near]

OK. Not trying to be confrontational but just trying to apply som rigour to the arguments.

If you were in the Smith vs. Finch case appearing as an expert witness for the insurance company and presented the above the questions you would get are:

You've measured the amount of energy the helmet absorped. Can you tell us the energy required to produce the head injury in question and is the amount saved relevant?

In the "better off" scenarios you describe can you tell us the amount of force reduction required to achieve each of these - either generically or for this particular set of circumstances.

Helmets don't increase the size of the head but the laws of physics show that they allow a force to be applied to the head with a larger moment. Yes or no?

So you believe that helmets can be effective in some accidents with motor vehicles. Tell us what the differentiating factors are are how they apply to this accident.

Without the answers it's speculation.

Can you describe this 'larger moment' in more detail in relation to a helmeted head and an unhelmeted head ?

Given that some people have a pre-disposition to a minor knock giving a fatal brain injury (Natasha Richardson), then this is not out of the question that a helmet would help them irrespective of however fast or slow they travel.

 

[MartinC]

Can you describe this 'larger moment' in more detail in relation to a helmeted head and an unhelmeted head ?

Given that some people have a pre-disposition to a minorknock giving a fatal brain injury (Natasha Richardson), then this is not out of the question.

Leverage. Instead of the force being applied at distance x from the pivot it's applied at x + y where x is the radius of the head and y the thickness of the helmet.

 

[col]

Leverage. Instead of the force being applied at distance x from the pivot it's applied at x + y where x is the radius of the head and y the thickness of the helmet.

Ah, thats all clear to me now.