A particular type of inflatable vehicle occupant protection device is commonly referred to as an air bag. An air bag is stored in a vehicle in a folded, uninflated condition at a location adjacent to the vehicle occupant compartment. When the air bag is to be inflated, inflation fluid is directed to flow from a source of inflation fluid into the air bag. The inflation fluid inflates the air bag from the folded, uninflated condition to an unfolded, inflated condition in which the air bag extends into the vehicle occupant compartment.
When the air bag is being inflated into the vehicle occupant compartment, it engages an occupant of the vehicle to help protect the occupant from a forceful impact with parts of the vehicle. The manner in which the air bag engages the occupant is determined in part by the configuration and location of the air bag relative to the occupant as the air bag unfolds and moves into the vehicle occupant compartment.