Injuries associated with airbag deployment

[Kimosabe]

http://emj.bmj.com/content/19/6/490.full

Emerg Med J 2002;19:490-493 doi:10.1136/emj.19.6.490

After being warned that by allowing one hand to pass 12 o'clock when steering, serious injuries could result if the airbag deployed at that precise moment, I decided to do a bit of digging around to see what I could find to either support or refute that claim. It's all I can do in order to hopefully silence the catastrophising observers who make such claims but with zero supporting evidence.

The most reputable research I could find was an entry in the BMJ which showed no conflict of interest or funding which could skew the research. I haven't yet found anything specifically relating to hand positions on steering wheels and resulting injuries from airbags at point of impact. Perhaps a chat with a local Uni might cause this to happen if it hasn't yet.

Here's an excerpt of the paper from the link above. I hope that by copy-pasting it here, doing so won't contravene international peace treaties or lead to an economic meltdown.

"An all encompassing review of data from the ongoing UK Co-operative Crash Injury Study (collecting data on all serious motor vehicle crashes since 1983) (R Cuerden, et al, IRCOBI Conference, 2001) found that, for seat belted drivers in frontal impact crashes, the presence of a deployed airbag led to:

No difference in maximum abbreviated injury score (MAIS) 2 or greater (2+) injury for similar crashes.

42% reduction in MAIS 2+ cranium injury.

70% reduction in MAIS 2+ facial injury.

No difference in MAIS 2+ chest injury.

Significantly more MAIS 2+ injuries to the arms and right shoulder."

So that airbags cause arm injuries anyway means hand position is a somewhat redundant point? Perhaps it's better to cause those who make such claims to have to support them with good quality information.

Does anybody have any such information?

[martine]

I applaud your efforts to find a definitive research but doesn't it intuitively make sense? If a hand is in front of the airbag during deployment it's either going to damage your hand/face or stop the airbag from cushioning your upper body and head...isn't it?

[Horse]

So that airbags cause arm injuries anyway means hand position is a somewhat redundant point? Perhaps it's better to cause those who make such claims to have to support them with good quality information.

That paper's from 2002!

Anywayup, two points:

1. If you're approaching a blind bend, so can't see whether there's any oncoming traffic, don't go past 12. If you can see there's no chance of a head-on, cross arms and twirl away to your heart and upper limbs' content.

2. If you are about to head-on into something, let go of the wheel.

I posted the advice in '2', which came from one of the world's experts in airbag technology (he has a PhD in it, I doubt there are many!) on a well-Linked safety group, but it was withdrawn by the manager as he felt it better to pass out "Don't have crashes" advice than accept the inevitable that people will still have them. Another part of the reason given was that 'pulling on the steering wheel can help apply brake pressure'. Fine, do that - but let go of the wheel immediately prior to impact.

NB I'm sure I heard that old Dennis fire tenders had poor brakes and flimsy steering columns . . .

[Kimosabe]

I applaud your efforts to find a definitive research but doesn't it intuitively make sense? If a hand is in front of the airbag during deployment it's either going to damage your hand/face or stop the airbag from cushioning your upper body and head...isn't it?

It does make sense if the airbag deploys but perhaps a personal example might help to expand on what lead to my curiosity.

I wonder what it takes to cause a front airbag to deploy. When I was told that "we don't allow hands to go over 12 o'clock because if the airbag deployed, it would break my arms", I was at first surprised that airbag deployment could occur at such a low speed. We were in a car park and I had just purposely taken a corner by what I thought was called 'predictive input'. That is to say that I took hold of the wheel at about 10 o'clock with my right hand, while keeping my left hand at 9 and pulled the wheel until my right hand was at around 3. Both hands at this point were opposite eachother. The car took the corner with no further input or drama until I straightened the wheel in the exact opposite way. The whole thing took a few seconds. I couldn't see anything wrong with what I did as I have done this many times and the instant catastrophised potential outcome seemed ridiculous and misplaced, even if somewhat predictable.

So true to form, I set about checking the information I was given for myself and this is as far as I have got so far. As always I am happy to be corrected and guided but only if it comes with reasonable information.

[Kimosabe]

Thanks Stressedave and Horse, I'm just trying to learn as much as I can from whatever crosses my path. Otherwise things can soon become quite hypothetical.

One more question. By letting go of the wheel while in a skid, do the front wheels right themselves? I would assume so but I've never had to control a skid.

It's all about learning, right?

[Horse]

How often do you practice skid correction because if you don't then you probably won't do what's required?

Also, how often on-road will you have time and space to successfully correct a skid - especially if it requires such dramatic action?


Edit: that practice can include non-driving, such as visualisation and armchair exercises. Plus, mentally preparing by identifying likely skid situations then having your reaction ready - so reducing reaction time.

[WhoseGeneration]

but I've never had to control a skid.
It's all about learning, right?

Never having had to control a skid, that's down to the fact that you have always been driving in an AD way.
Learning to experience skid control, just pay and play somewhere. Though as Horse has previously said, it's doubtful whether public roads provide the space, considering others possibly there, to correct without damage.
The only circumstance I'd expect an AD to have to correct a skid would be at an already slow speed on ice or very snow covered roads.

[jcochrane]

I applaud your efforts to find a definitive research but doesn't it intuitively make sense? If a hand is in front of the airbag during deployment it's either going to damage your hand/face or stop the airbag from cushioning your upper body and head...isn't it?

It does make sense if the airbag deploys but perhaps a personal example might help to expand on what lead to my curiosity.

I wonder what it takes to cause a front airbag to deploy. When I was told that "we don't allow hands to go over 12 o'clock because if the airbag deployed, it would break my arms", I was at first surprised that airbag deployment could occur at such a low speed. We were in a car park and I had just purposely taken a corner by what I thought was called 'predictive input'. That is to say that I took hold of the wheel at about 10 o'clock with my right hand, while keeping my left hand at 9 and pulled the wheel until my right hand was at around 3. Both hands at this point were opposite eachother. The car took the corner with no further input or drama until I straightened the wheel in the exact opposite way. The whole thing took a few seconds. I couldn't see anything wrong with what I did as I have done this many times and the instant catastrophised potential outcome seemed ridiculous and misplaced, even if somewhat predictable.

So true to form, I set about checking the information I was given for myself and this is as far as I have got so far. As always I am happy to be corrected and guided but only if it comes with reasonable information.

Just a small point what you describe was not "predictive" steering. Predictive steering is where both the hands are prepositioned before steering, then, in a fixed grip/hands manner, turning the wheel and if judged correctly the hands will be at 3-9 at the maximum turn point. Hence the term predictive as you predict the amount of turn required and pre position your hands based on that prediction.

What you describe sounds, like what is referred to as "taking a good handful of steering wheel" before commencing PP The upper hand passes over 12 o'clock so quickly in the early phase of steering that any issue is surely remote.

On the other hand, and I am only guessing, if one hand has crossed past 12 'o'clock and then held there for most of the turn as might occur if using fixed input then there may be an issue. Personally I only use fixed input up to 12 o'clock. If more of a turn is required I would use PP.

[Carbon Based]

What you describe sounds, like what is referred to as "taking a good handful of steering wheel" before commencing PP The upper hand passes over 12 o'clock so quickly in the early phase of steering that any issue is surely remote.

As well as the brevity of that phase, I wonder what effect the position of the elbow has on this. With bent arms, right hand to 10 o'clock, or left hand to 2 o'clock may not put forearms between the wheel's hub and the face.

Does anyone have a dummy and a car they want to scrap?

[Horse]

Not explosive, it 'deflagrates' I think.

Another reason for only deploying when needed is the quantity of devices in some cars:
- dash / steering wheel airbag
- side curtain
- A pillar
- seat belt tensioner
- pedal box retraction

And maybe more that I don't know about!

[125isfine.]

Chris Gilbert covers this in one of his videos.
The airbag can deploy with up to 1000psi of pressure and at a speed of up to 200mph. Chris does mention some of the injuries that he knows about but I don't know if it is first hand experience.
As I've always used pull push and anything else feels strange, it doesn't bother me.
Just stating an opinion, not looking for a protracted argument .

[Flexibase]

Here is some first hand evidence. There follows a short extract from a complete description from http://www.ridedrive.co.uk (although it doesn't appear to be there now) which was reproduced in full with their consent in my "Advanced Driving" CD: It is written by a police officer who was the front seat passenger at the time.
When I got out of the car my face was covered in what is best describe as gravel rash and with droplets of blood standing on the surface of my skin. I had two gouged furrows up my forehead caused by the sunglasses and my eyes, nostrils and lips were stinging from the effect of the chemicals from the airbag detonator. Sodium Azide (NaN3) and Potassium Nitrate (KNO3) were reacting with the moisture in these areas of my body. Apart from that I was intact, and the mild discomfort of a stinging face was a small price to pay for still being in one piece, and more importantly, still being alive.
You will note that I have so far not mentioned the driver of the car, and for the purpose of sharing this account with you I shall introduce him now as Dave. His situation was different, as just before the main impact, and whilst fighting for control of the car, Dave managed to get his right forearm across the centre area of the steering wheel. The driver’s airbag is located in the steering wheel and when this deployed it smashed Dave’s arm into his face, breaking and displacing his nose, but his arm didn’t stop there.
The force of the airbag pushed it over the top of his head, and his seat head restraint, before it ended up behind the middle of his back. You might at first think this should not be a problem, but if you are sitting in a chair whilst reading this page, put the back of your forearm against the bridge of your nose. Now move it upward to the top of your head before trying and get it over the top and down your back. You can’t do it can you?
Now imagine what it would be liked for someone or something to force it to do that. The broken nose was not too much of a problem, as that kind of injury will usually heal well, but the effect of the arm being forced into an unnatural position was something more serious. The movement pulled Dave’s shoulder out of its socket and tore all his muscles and ligaments to ribbons.
That crash happened in 1999 and, when I retired from the police service in 2005, Dave was still being treated for that shoulder. The prognosis was that it will never be fully fit again, but in spite of his injury, he too was still able to walk away from the car, and like me, he owes his life to the seatbelt and airbag system fitted to the car.

[Horse]

Thanks for posting that - I'd looked for it a while back.

I wonder whether his 'fighting' worsened the injury? Perhaps the average driver wouldn't know how so wouldn't have tried, and give the range of styles and grips used they might not be so badly injured.

Certainly it's not something that regularly gets talked about.

[Kimosabe]

Just a quick reply to thank you all for your considered responses before I go back and re read them all properly. It's a lot to take in.

[Kimosabe]

So that airbags cause arm injuries anyway means hand position is a somewhat redundant point? Perhaps it's better to cause those who make such claims to have to support them with good quality information.

That paper's from 2002!

1. If you're approaching a blind bend, so can't see whether there's any oncoming traffic, don't go past 12. If you can see there's no chance of a head-on, cross arms and twirl away to your heart and upper limbs' content.

I can't find the twirling page in HTBABD. Is that what senior ADers refer to as 'Random Input'? I suppose as long as it's safe and smooth and has a name

Yes I noticed and wondered about that date too but as a sample, I took it to be an example of comparative values. Not something I want to get hung up on, just that I'm looking for defences for anything I'll have to explain as an observer and I like to be able to support what I say or at least provide somewhere for new ADers to go post drive. Has airbag tech changed significantly since then?

I'd like to see a sticky for high quality reference material which supports or refutes our various practices, as it's easy to make claims or to dismiss them through Google-based confirmation bias. something like an AD Wiki.