Side airbag module arrangement in a motor vehicle seat

The air bag module (3) is located on the appropriate long side of the seat. Behind it, there is an external covering formed by the rear shell (4) of the backrest. Between module (3) and backrest shell, a reinforcing component (6) is located. When the module is activated, the airbag is prevented from emerging from the rear of the backrest, where its shell covers the module.