The importance of shoulder belts

Using a booster without a shoulder belt increases the risk of a child’s head hitting a hard surface in a collision. For this reason, you should never use a booster seat with a lap belt only. It is generally best to use a booster seat with lap/shoulder belts in the back seat.
Move a child to a different seating location if the shoulder belt does not stay positioned on the shoulder during use.
Follow all instructions provided by the manufacturer of the booster seat.
WARNING: Never place, or allow a child to place, the shoulder belt under a child’s arm or behind the back because it reduces the protection for the upper part of the body and may increase the risk of injury or death in a collision.
See also:
Airbag supplemental restraint system (SRS)
The airbag supplemental restraint system (SRS) is designed to work in
conjunction with the safety belts to help protect the driver and front
outboard passenger from certain upper body injuries. ...
Hitches
Do not use a hitch that clamps onto the vehicle’s bumper or attaches to
the axle. You must distribute the load in your trailer so that 10–15% of
the total weight of the trailer is on the tongue. ...
Hitches
Do not use a hitch that clamps onto the vehicle’s bumper; use a
load-carrying hitch. You must distribute the load in your trailer so that
10–15% of the total weight of the trailer is on the tongue ...
