Chevrolet 1994 Lumina Owner's Manual page 29

3.
To make the lap part tight, pull down
on the buckle end of the belt as you
pull up on the shoulder part.
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'd 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's a sudden
stop or a crash.
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