Miata Mailing List: May 1998, Message #170

sponsored by

< Akira wrote:
  ( I searched the NHTSA and IIHS websites for info on seatbelt fatalities and
came up empty, but IIRC there have
 been reports of such in the media.  Anyone?)

 >Sandy Robertson wrote:
 ( snip )
 ....A few - very few - of these injuries were exceedingly serious.  I believe
 >one or two cases of paraplegia were reported and a few deaths from ruptured
 >great vessels or undiagnosed mesenteric bleeding.  This changed due to the
 >simultaneous improvement in both seat belt design and the diagnosis and
 >treatment of trauma.   Despite these rare but devastating complications of
 >seat belt usage, at no time was there any question of the value of seat
 >belts in reducing both the injury and fatality rate of drivers and
 >passengers of cars involved in accidents.
 >
 
Kevin wrote:
 > I just thought I'd add that seatbelts are continuing to be improved.
Recent
 technology includes things called pretensioners and force limiters have come
 into use in many cars this year.  The pretensioner is an explosive charge
 within the seatbelt mechanism that discharges in an accident of sufficient
 severity to trigger the airbags.  This charge instantly cinches the belts
 tight so that the occupant is held tightly in the seat on impact.  Then the
 force limiter comes into play by releasing some of the tension on the belt
 just at the instant the air bag reaches full deployment to prevent the belts
 from injuring the occupant and to allow the airbag to stop the forward
 motion of the occupant.  I think this is pretty cool. >
 
Yes, but.

You're going to be surprised to hear this from me, but I'm going to play
Devil's advocate for a moment.  

We're talking about new safety technologies being introduced here.  Has anyone
considered any of the possible detrimental side effects of such devices?  I
can think of a couple possibilities that may warrant further research:

In extremely rare cases, occupants who are out-of-position at the time the
pre-tensioner explodes  ( My Buddha, two more "BOMBS" in my car? ;-) ) have
the chance of being injured by the retracting belt.  Some occupants who might
be shorter or taller than normal, may experience an increased incidence of
bruised shoulders, sternums, or even arms from the force of the belt as it
tightens.  If the occupant is out-of-position AND the height adjuster of the
shoulder restraint is not adjusted correctly (operator error), it is not
outside the realm of possibility that this combination of factors MIGHT even
cause a fatal neck injury.

<stepping back into my former personality>

Does any of this sound remotely familiar?  I must point out that I have not
read anything of the above supposed possibilities, I have no proof that any of
those possibilities exist, and I challenge anyone to find the information at
this stage of their development that might prove or disprove my speculation
(as a matter for further discussion---not as a personal vendetta or anything.)

That said, I must express my opinion that these new safety technologies show
real promise in helping to reduce injuries and fatalities.  They are being
designed to work together with existing safety technologies (belts and bags)
and are also a possible answer to one of the negatives---the incidence of
injuries to the extremities from airbag deployment.  (Yes, one of the subjects
of that tired NHTSA Third Report to Congress that has been the centerpiece of
much of our discussion on this subject as of late.) 
--
    "Akira"
'96 Chaste A/T      http://www.eunos.com/keith/stripes/akira.html

"Open the door.  Open the top.  Open the mind."
    ---from '99 Roadster sales brochure (Japan)