The head restraint in a vehicle does not help you rest your head, matter of fact it helps you not to break your neck in case of collision. It is always attached to the top of the car seat. Though it used to be an optional accessory in 1921 it is now mandatory for each and every single automobile.
It is the head restraint that will reduce neck injuries in case of a collision, and so it is important to have your head lined with the headrest, but not the neck alone, as this would be extremely dangerous in case of collision.
Most cars have manually-adjustable head restraints, but they all have to be 27.5 inches above the seat reference point by law.
To adjust the head restraint is something that has to be done every time you get in a car, making sure it is cushioning the back of your head, that is, no lower than your ears. Make sure that all of your passengers are following the same procedure.
GoodTake a look at the second picture below in which a well- adjusted head restraint is in use, this will save you the pain of possible neck injury in case of collision and it will definitely protect your life if you are involved in a serious car accident. The seat back angle is upright, which allows the your head to rest on the head restraint.
Take another look at the second picture and notice that the back of the head rests on the head restraint, not the neck.
BadCheck the picture below out, and observe two terrible ways of sitting and using the head restraint. In the first picture you can see how he does not rest his head, leaving some room between his head and the head restraint, which means that in case of collision his head can still impact against the head restraint, hurting both his neck and head.
In the second picture you can see that the head restraint is at the same level as her ears, we can say that it is too low, and in case of collision the head restraint will not protect her neck, and it will not absorb the impact, reducing the possibility of being injured.