Most people never bother to adjust the headrest. They just leave it the way it came when they bought the car.
The correct position for a headrest is even with the head and no more than two inches behind the center of the back of the head. If the headrest is too low (behind the neck), the force of an accident could bend the head back over the headrest, causing serious injury to the cervical (neck) area.
Occupants of a car should not recline their seats while the car is in motion because it increases the distance between the head and the restraint, and in addition, puts the occupant in a more hazardous position should an accident occur.
