Buick 2001 Century Owner's Manual page 51

CAUTION:
Newborn infants need complete support,
including support for the head and neck. This is
necessary because a newborn infant's neck is
weak and its head weighs so much compared
with the rest of its body. In a crash, an infant
-
in a rear facing seat settles into the restraint,
so the crash forces can be distributed across the
strongest part of an infant's body, the back and
shoulders. Infants always should be secured in
appropriate infant restraints.
CAUTION:
The body structure of a young child is quite
unlike that of an adult or older child, for whom
the safety belts are designed. A young child's
hip bones are still so small that vehicle's regular
safety belt may not remain low on the hip bones,
as it should. Instead, it may settle up around the
child's abdomen. In a crash, the belt would apply
force on a body area that's unprotected by any
bony structure. This alone could cause serious or
fatal injuries. Young children always should be
secured in appropriate child restraints.
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