Chevrolet 2005 Astro Owner's Manual page 39

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 pelvic bones. And you would
be less likely to slide under the lap belt. If you slid under
it, the belt would apply force at 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 safety belt locks if there is a sudden stop or
a crash.
CAUTION:
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You can be seriously hurt if your shoulder
belt is too loose. In a crash, you would move
forward too much, which could increase injury.
The shoulder belt should fit against your body.
To unlatch the belt, just push the button on the buckle.
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