Brace before impact...!

[anonymous-user]

I had a wee disagreement with a friend not he subject of crashing.

Say for example your going to crash head on. There is nothing you can do to avoid the crash, you ARE going to crash.

My argument is/was that to minimise injury you should tense up and get ready for impact whereas friends opinion was that my way is dangerous as you can break more bones that way!

He stated it is best to go all floppy and wait for impact

None of us have actually had any 'proper' accidents so our experience is based on bullst and guesswork however judging by the 'crash pics' thread I know some of you guys are hardened veterans when it comes to crashing.

Can anyone shed any light?

[anonymous-user]

Well this is the problem.

I always thought that by bracing up your going to lessen any physical injury (well a lot of it) whereas being floppy you are just going to be thrown around bouncing off bits of interior.

[anonymous-user]

Monkeylegend said:

Put it like this. Try running front first ,twice, into a brick wall, once with a floppy and once with a stiffy, then tell us which hurts the most.

Sorry i refuse to run into a wall with a floppy and then again with a stiffy!

What sort of perv are you???

[anonymous-user]

Floppy, certainly. Unless you let your limbs flail around and smash into stuff. I would call it relaxed rather than completely rag doll.

With relaxed limbs you are giving them the ability to absorb some shock forces by allowing them to move slightly. Tensed up you are not and so all the shock is dissipated straight through them and none is dissipated through movement.

It's essentially the difference between a ductile and a brittle material in a shock load test. If you dropped a mass on to each of them you'd see the ductile one deflect more than the other and therefore that one has a higher resilience to shock.

ETA:

reggie82 said:

I would expect it is to do with babies not tensing up and maybe also that their bones aren't as brittle.

Yep they mention this in air crashes. A lot of the time the children survive as their bones haven't yet developed fully and have a greater resilience to shock as described above.

Edited by MSTRBKR on Monday 3rd January 13:20

[anonymous-user]

Well some really good information here, i was always under the impression that if you tense up you will be fine otherwise by being a floppy you will bounce around like a ricochet (sp).

[anonymous-user]

clabcon said:

reggie82 said:

twazzock said:

rottie102 said:

twazzock said:

DanGPR said:

Mr2Mike said:

hairyben said:

dave9 said:

floppy - that's why babies often survive unhurt

Yeah there's been a couple of big airline disasters where the only survivor was a baby.

I'm pretty certain that's purely down to mass rather than "floppyness" i.e. F=MA. The same reason cats can fall out of tower blocks and survive but people generally can't.

Is a baby not equal in mass to an adult? Not weight, but mass.

What the fk are you talking about?

http://en.wikipedia.org/wiki/Mass_versus_weight

I know the difference, thanks; I went to secondary school.

I presume he was posting it for the benefit of the person who thought a baby has the same mass as an adult, rather than for you?

I don't think the baby's mass has anything to do with surviving crashes. Ok, the force the baby hits anything with would be smaller, but an adult has a bigger surface area to diperse the force across.

So although Force = Mass X Acceleration, Pressure = Force / Area.

I would expect it is to do with babies not tensing up and maybe also that their bones aren't as brittle.

It's all to do with the surface area:volume ratio. Babies have a much larger SA:V compared to adults, thus spread their small force from low mass over a relativly larger surface area.

And Also Weight = Mass x Gravity

Nothing to do with surface area and everything to do with volume, mass, deceleration and the body's natural ability for shock absorbance.

EFA

Edited by MSTRBKR on Monday 3rd January 15:38

[anonymous-user]

clabcon said:

reggie82 said:

Why do you say volume is important, but surface area isn't?

+1

This should explain why SA is important in a way even the vast majority of the public should be able to understand.

I'm just a student, but from what I've learned I think what I'm about to say is pretty much there

I probably shouldn't have said SA has nothing to do with, as it does when you actually hit an object. I was thinking talking about deceleration forces. The deceleration force of the accident acts upon the entire volume of a person, it isn't as simple as stress = load / area. Essentially, the higher the volume of the person the lower the stress on each cubic mm of their body. They will have a greater resilience to the stresses and will be able to absorb the energy better. Of course if they actually hit objects within the car then SA comes into play with Stress = Load / Area

It's been said children fare better in accidents which might be down to their mass. Their mass is lower than an adult so the deceleration force on their body is lower (Force = Mass x Acceleration). This in turn with the softer bones gives them a better chance in accidents (I think).

Of all this though, the really important thing is to stay relaxed I reckon

EFA

Edited by MSTRBKR on Monday 3rd January 18:51

[anonymous-user]

Now thats an interesting one...

Should you let go of the steering wheel too?

[anonymous-user]

Slightly different scenario but I was at an NYE party a few years ago when a drunk guy left the house and wandered into the main road

A maserati hit him at appx 60-70 mph, he never saw it coming

He was in hospital in a coma for a few days as his brain was swollen, but apart from that, no broken bones IIRC just heavy bruising, I remember people being very shocked at how little he was hurt

Apparently that was due to him not seeing it and not tensing up, if he had they reckon at least 2 broken legs and the rest