GMC 1994 Yukon Owner's Manual page 36

Q:
What's wrong with this?
A:
The shoulder belt is worn under the arm. It should be worn over the
shoulder at all times.
I
A
CAUTION:
You can be seriously injured if you wear
the shoulder belt under
your arm. In a crash, your body would move
too far
forward,
which would increase the chance of head and neck injury. Also,
the belt would apply too much force to the ribs, which aren't as
strong as shoulder bones. You could also severely injure internal
organs like your liver
or
spleen.
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