GMC 2010 Acadia Owner's Manual page 74

3-20 Seats and Restraints
First, before you or your
passenger(s) wear a safety belt,
there is important information you
should know.
Sit up straight and always keep
your feet on the floor in front of you.
The lap part of the belt should be
worn low and snug on the hips, just
touching the thighs. In a crash,
this applies force to the strong
pelvic bones and you would be less
likely to slide under the lap belt.
If you slid under it, the belt would
apply force on your abdomen.
This could cause serious or even
fatal injuries. The shoulder belt
should go over the shoulder and
across the chest. These parts of
the body are best able to take belt
restraining forces.
The shoulder belt locks if there is a
sudden stop or crash.
Q: What is wrong with this?
A: The shoulder belt is too loose.
It will not give as much
protection this way.