From: lowry@watson.ibm.com (Andy Lowry)
Subject: Re: Car seat question summary
Date: Fri, 31 Jul 1992 18:49:51 GMT
Disclaimer: This posting represents the poster's views, not necessarily those of IBM
Organization: IBM T.J. Watson Research Center

In article <13722@gazette.bcm.tmc.edu> pburch@roc.mbcr.bcm.tmc.edu (Paula Burch) writes:
 > In article <9207302119.AA06709@fieser.brynmawr.edu>, chirlian@fieser.brynmawr.edu (L.E. Chirlian) writes:
 > |> 
 > |> 	3) All the people who answered whose children weighed >20lbs
 > |> before they could sit continued to keep them rear facing in a
 > |> full-sized car seat at least until they could sit up if not longer.  
 > 
 > What about an 18-pounder who sits well? Is it okay for her to be facing 
 > forward? This is my friend's baby, and she loves facing forward. She's
 > eight months old.

My understanding is it comes down to a trade-off among a few factors:

 - In a front-end collision (by far the most common), a rear-facing
   seat gives more support than a forward-facing seat.  The impact is
   spread over the child's back rather than over the much smaller area
   of contact with straps (this reduces likelihood of joint failures
   and injury to internal organs), and the head is prevented from
   snapping forward dangerously.  As the child's muscles (and
   particularly neck muscles) develop, this is less of a concern (it
   doesn't vanish, it just lessens).
 - As babies get older they start becoming less content with a rear
   view.
 - Rear-facing car seats may be designed with certain stress
   tolerances in mind, so putting babies in them that are larger than
   those tolerances assumed could cause the seats to fail.

I don't think I've ever heard of a reason that a rear-facing seat
would be more dangerous than a front-facing seat in a front-end
collision, assuming the seat is able to handle the strain without
failing.

Note that if you're unfortunate enough to experience a severe rear-end
collision, everything's backward; your infant would have been safer in
a front-facing seat.

The above would indicate that it's safe to turn the child around when
they have developed enough strength to withstand a frontal impact with
a reasonably small chance of injury.  One would also want to use a
front-facing seat that won't fail under the given load in preferance
to a rear-facing seat the would fail, so if the baby's too heavy for
the rear-facing seat you're better off switching.  (Of course, if you
doubt the baby's strength you're best off getting a stronger
rear-facing seat.)

And given that in all cases the seat offers far from perfect
protection, the best thing you can do to prevent automobile-related
injury to your child is to drive defensively.  This includes shedding
any aggressive road attitudes you might have (i.e. let the guy in
who's trying to enter your lane, even if you're running late), and
being as predictable as possible to other drivers (e.g. signal, and
*NEVER* back up to an exit you just missed... live with the mistake
and find your way back from the next exit, even if it's fifteen
minutes away).

Remember: driving and riding in automobiles is, statistically, the
single most dangerous activities that most people will ever undertake.
You need to aggressively pursue safe driving practices if you want to
minimize your risk and that of your passengers.
--
Andy Lowry, lowry@watson.ibm.com, (914) 784-7925
IBM Research, P.O. Box 704, Yorktown Heights, NY  10598