From Dr. Barry Matthisen,
Proper head restraint position can reduce your risk of injury in rear-end crashes. Head restraints that are in the wrong position, like too low, can increase your risk of injury as the head restraint acts like a fulcrum as your head whips back.
Some car seats are not equipped with an adjustable head restraint. Some cars are equipped with whiplash designed prevention seats which reduce the risk of injury like WHIP seats. Some head restraints can be adjusted, and the IIHS (Insurance Institute for Highway Safety) tests many cars, and designed the picture/graph below for proper head restraint position:
There are 2 parameters to look at when assessing your head restraint position. The first is the backset. As you can see, the distance away from your head to the head restraint (backset) should be no more than about 5 cm away. The old rule of thumb was to make the backset no more than your fist between your head restraint and your head. Now, the new standards say it should be a bit closer. The reason for this is that the neck can spring into a reversed “S” shape curve within 100 milliseconds causing neck injury before the head hits the head restraint. The closer the head restraint, the less risk of this occurring.
Next is the height of the head restraint. The crown of the head restraint should meet the top of the back of your head. The reason for this is that the mid back is naturally curved backwards (kyphotic curve). When the seat back impacts the mid back, it very quickly flattens this curve, causing compresive forces upward on the neck and head and downward against your low back, making you rise a few inches before you contact the head restraint.
If you have any questions, just call us and we’ll be glad to help you!