Crossed arms and Air Bags

[Martin A]

Hi All

I have read that some people think that having the arms crossed in event of airbag deployment while steering might lead to facial mutilation.

Is there any evidence to suggest that this is a real world problem or is it just a red herring. Are there any recorded instances where this has been proved to have caused physical damage? Are these details accessible or is this just another example of using spurious claims and urban myths to scare people into believing dogma about the advantages of a particular steering method?

After all, the head isn't flung back with enormous force when contacting an airbag, merely cushioned. We must remember that in event of a massive g deceleration that arms will also 'gain weight' like the rest of the body. Think of a 5kg arm going forward at maybe 50mph being hit by a 0.01 kg piece of fabric coming the other way at 200 mph. I know which my money would be on as exerting the greatest force. In fact, if using gentle push-pull mightn't the arms slip off the steering and break all the fingers as they impact with the indicator and washer stalks? Perhaps push pull is therefore inherently more dangerous.

Knowing that the danger of airbag deployment might be a problem in countries where push-pull is not advocated, air bag and motor manufacturers are potentially letting themselves in for some serious litigation.....Prosecuting counsel, incredulously, "You mean you knew this could rip someone's face off and yet you still fitted it to one million automobiles?"

Show me repeatable evidence before I believe.

Hope this helps

Best regards

Martin A

[Astraist]

Airbags inflate at speeds of slightly over 320kmph (over 240mph), equal of hitting a solid brick wall at a speed of 25kmph. Given that they should only deploy at an accident in a velocity of 30mph or more, the impact would be even stronger, at least slightly above 260mph!

Hand fractures by themselves are perhaps not as grave as possible damage to the parts of the hands that are hooked into the wheel (people driving with hands hooked inside parts of the wheel), and the impact of the hand at other parts of the body (normally the face, if the driver seats too close), or other immobilized parts of the car.

Hand fractures can surely occur when hands are placed above the 10 and 2 hours on the rim (though not if precisely in 10 and 2). An 8 to-4 position, which is intended to decrease the chance of injury due to airbag inflation is highly unrecommended.

Because I always promote 9 and 3, and fixed-input as a means of quick means of making a "bump to bump" steering input for the sake of evasive manouvering, I think that the factor of possible arm cross or arm fracture due to airbag inflation is one of the lesser considerations in the configuration of steering techniques and hand positions:

The main thing is to supply the driver with a position that offers good control, avoiding the possibility of airbag inflation to a minimum. Keep in mind, that the driver is not always the sole occupant of the vehicle, neither is he the sole party involved in most car crashes. By driving in a position like 8 and 4, the driver's control is so limited that he is posing a danger to other road users and his passengers, who are not in the same risk of arm fracture.

As for the driver himself, let me say one can never be fully secured from hitting the airbag. It's a calculated risk you take when you board a vehicle, and you cannot refrain from sufficient car control in order to avoid a relatively rare risk. Not to mention that a bruised and broken arm is far better than a head-on collision or something of that nature.

[Horse]

I'd heard of broken noses etc from arm:face impact.

But no 'scientific' proof.

[Astraist]

As I have now remembered, the mass of the body is placed further away from the wheel than the hands, and therefore hits the airbag after it has inflated, at which case the bag would indeed soften the blow. The hands, however, are in risk of hitting the airbag as it inflates (about 23cm from the base of the steering wheel). This risk also includes the sternum of drivers who are too short, sit too close or are not fastened.

[zadocbrown]

There's been plenty of research on this in the US. It seems the problem is a real one - that there is a risk is self evident when you think through the possible sequence of events.

The bottom line though, is that you are more likely to be saved by an airbag than to be injured by one - so in the balance of probability you are better off having one.

[MrToad]

There's an account here of an accident that resulted in a serious airbag-related injury - towards the end of the article:

http://www.ridedrive.co.uk/tipoffs11.htm

[Standard Dave]

I've seen on a number of occasions injuries caused by wearing glasses when an air bag inflates in the same way as injuries from tripping over are often made much worse by the presence of glasses.

The issue of arms over the top and crossed arm steering with air bags isn't that the airbag will injure the arm but that being crushed between your face and the airbag will. The airbag isn't designed to have your arms between your face and the bag as such injury will result to either face or arms.

[Astraist]

There's an account here of an accident that resulted in a serious airbag-related injury - towards the end of the article:

http://www.ridedrive.co.uk/tipoffs11.htm

Julian Smith (whose articles I like, though I question some of the techniques he implies) is right: An airbag is simply a bomb. It's activated by a small detonator. However, the bag also has little ventilation holes, that allow the combusted gas to evaporate after it has inflated to size necessary to cushion the driver. As said, if the airbag hits anything while it inflating, it will inflict damage on that object. An unbelted driver, for instance, could be killed directly by the airbag (although he would probably be killed without it too).

[standards]

Some time ago on a skid pan session I got talking to a doctor who spent time attending emergencies with the ambulance service and he was quite graphic about watches being planted firmly in wearers face as the airbag deployed when arm was across the wheel.

The merits and otherwise of various steering methods on the skid pan were obviously a hot topic and this was the anecdote I have in mind as I try to stick with the Roadcraft method of steering (in most circumstances).

[Martin A]

Hi All

All I am seeing so far is anecdotal evidence. 'Plenty of research' is mentioned but with no references to follow, nor have I managed to find any. The passenger in the Police crash in MrToad's link about injuries caused by airbags admits to being confused after the crash and could not possibly have seen the cause of his driver's arm motion as everything happens too fast anyway. The air bag may or may not have been the problem. It might well have been the instant stop from 50mph that caused the problem. Perhaps the driver's style of steering and a decision to not move his hand across the wheel earlier in the sequence of events contributed to the crash in the first place. We shall never know but neither should we take the passenger's beliefs about cause and effect as fact. There is no citation on wikipedia about such a cause of injuries either.

What there does seem to be hard evidence for is that watches and glasses can cause injury, possibly even to others, in the event of a crash. Due to the forces involved in a crash it is impossible to control the movement of limbs which may strike others.

It's unlikely anyone will stop wearing either a watch or glasses that can cause injury or wear a helmet inside a car on the face of this evidence, however such practice would have a demonstrably greater effect on mitigating serious facial injury than any particular style of steering.

Until such time as steering campaigners increase their own safety, and campaign for others to do so, by the removal of 'accessories' on the arms, hands and face I think we should all doubt their inconsistency about safety and their reasons for advocating a particular steering style being mainly about belief rather than fact.

Best regards

Martin A

[Astraist]

Some time ago on a skid pan session I got talking to a doctor who spent time attending emergencies with the ambulance service and he was quite graphic about watches being planted firmly in wearers face as the airbag deployed when arm was across the wheel.

The merits and otherwise of various steering methods on the skid pan were obviously a hot topic and this was the anecdote I have in mind as I try to stick with the Roadcraft method of steering (in most circumstances).

And by that method are you reffering to a shuffle/pull-push technique?

The reason I say this, and also emphesize control issues rather than safety in the event of airbag inflation, is that trying to steer effectively (particularly in a skidding situation, but also in other, more mondane scenarios) and to avoid hitting the airbag are potentially contradicting goals: One technique I sincerely hate is gripping the wheel at 8 to 4 and shuffling it from it's lower portion alone. Another technique which is not to my professional liking is the one advocated in the articles of Julian Smith, who has been mentioned before in this thread. It's quite similar to what I advocate, however done by relocating both hands, instead of one, theortically making for better control, but actually limitating the control somewhat at the end.

The steering method I advocate, albeit carrying great similarities to pull-push, does in times involve passing one hand across the steering wheel or even across at the bottom of it, in order to excert a great deal of steering wheel rotation in a single hand movement. Additionally, when evasive manouvering are concerend, the advice is for the driver to steer completly fixed-input, which can lead to momentary forearm crossover.

The idea is that this position will optimize control, allowing to avoid airbag inflation to begin with, and also minimize the time spent with the hands crossed over and maximize the time the driver is in the 9 to 3 position. I too know several paramedics and people who observe car accident scenes, and while they have reported airbag inflation as a potential danger which indeed inflicts injuries, they are also advocating the same technique I imply!

[Flexibase]

See AD-UK Forum - General Chat - "Is the Driving test out of Date?" for a good article, with evidence, on this from retired Met. Police Sergeant Chris Gilbert of "Roadcraft Video" and "Ultimate Driving Craft" DVD fame.

[Horse]

What there does seem to be hard evidence for is that watches and glasses can cause injury, possibly even to others, in the event of a crash. Due to the forces involved in a crash it is impossible to control the movement of limbs which may strike others.

I did a track riding session last year.

As part of the briefing we were advised to remove anything from our pockets we wouldn't want a surgeon to have to dig out if it was implanted into us during an impact . . .

That said, I don't worry about it during road riding.

That said . . . as I was typing I thought "Hmmm . . . but I wouldn't have a pen in chest pocket".

[MrToad]

It's not airbag related, but this link seems relevant:

Girl almost died in crash as navel stud shot through her ‘like a bullet’

[Martin A]

Hi All

See AD-UK Forum - General Chat - "Is the Driving test out of Date?" for a good article, with evidence, on this from retired Met. Police Sergeant Chris Gilbert of "Roadcraft Video" and "Ultimate Driving Craft" DVD fame.

There is no scientific evidence in the article. Two of the links in the article lead nowhere and the third which is over a dozen years old refers to an option to turn airbags off due to concerns about injuries attributed to airbags. It never specifies how such injuries are caused, nor does it provide any scientifically repeatable proof that having a hand across the wheel is going to result in injury.

All Chris Gilbert's article provides proof of is that he is very experienced in a particular method of steering and by using it he personally has remained accident free. There are many factors, like anticipation, that could negate steering method as a noteworthy safety factor.

The fact that John Whitmore, who has probably not regularly driven in low grip conditions for some forty years, was unable to control a car on a skid pan with the aplomb as someone who regularly practices such skills is unsurprising too, but once again is evidence only of an individual nature.

Hope this helps

Best regards

Martin A