The most effective way to prevent whiplash injuries is to purchase a car with a good rated head restraint and then to adjust the head restraint properly. While other safety devices and systems are available to help protect you in front and side impact collisions (seat belts, airbags, etc.), a properly designed seat and adjusted head restraint is the most effective safety feature for protecting yourself and your family from injuries that happen in a rear-end collision.
Understand How Your Seat and Head Restraint Work
The following image portrays how your body interacts with your vehicle seat and head restraint. The top row of images shows a POOR rated head restraint; the bottom row portrays a GOOD rated head restraint.
Picture courtesy of the Insurance Institute for Highway Safety
At impact, the vehicle is accelerated forward causing the seat to push against your back.
- Your body is cushioned by the seat while your head and neck continue to move back.
- If your head is unsupported due to an improperly positioned head restraint (top sequence), it continues to move backwards over the head restraint
- Properly adjusted head restraints (bottom sequence) protect your neck by keeping your head and body aligned throughout the collision.
Is Your Head Restraint Adjusted Correctly?
The best way to make these adjustments is to have another person adjust the head restraint for you the first time while you sit properly in the seat. You can then view the position (even mark it with tape or a marker on the brackets) and repeat the positioning later should others use the vehicle. However, you can do it yourself using the following process.
Position your seat appropriately
Your seat should be inclined to less than a 20 degree angle. Sitting in this minimally inclined position will help keep you in the seat during a rear end collision.
Check the height of your head restraint
The proper position is to have the top of the head restraint level with or above the top of your head. You can measure this by placing your hand on top of your head and adjust the head restraint to be touching your hand.
Is your head restraint close enough?
The proper position is to adjust the head restraint such that it is about 5cm (2 inches) from the back of your head. Closer head restraints are twice as effective at preventing injuries as those set too far back. Closer means that your head will have less distance to build up speed and load the neck during an impact.
This poorly adjusted head restraint is set both too low and
too far from the back of the head.
This leaves the head and neck unsupported in the event
of a rear-end collision.
This correctly positioned head restraint is set at the proper
height for this individual and is about 5cm (or less)
away from the back of the head. This will provide significantly
better protection for the head and neck in a rear-end collision
than a poorly adjusted head restraint.
Head Restraint Awareness
Unfortunately, awareness of the importance of head restraints remains very low both in Canada and around the world. An Insurance Bureau of Canada study performed in 2002 showed that in Canada about 86% of head restraints are adjusted improperly.
Thatcham (also known as The Motor Insurance Repair Research Centre) has performed research on head restraint usage for UK vehicles:
Initially, Thatcham's engineers studied head restraint usage patterns on UK roads. They observed the position in which the driver and passenger head restraints were set, and assessed the level of protection the position offered to the occupants in a typical low speed crash. The results indicated that 72% of front seat occupants failed to adjust their head restraints correctly or had head restraints that were incapable of offering any protection. Of the remaining 28% who had their head restraints adjusted correctly, they noted that 11% of their restraints were of a fixed, one piece design such as those fitted to most Volvo vehicles.
Raising awareness about how to properly adjust your head restraint remains a very important aspect of reducing whiplash injury on a large scale.
While head restraints are very important, they are only one of the important safety features you should always look for when purchasing a vehicle. The more you know about the overall safety of your vehicle, the better you can prevent whiplash and other injuries from vehicle collisions.
Insurance Corporation of British Columbia
BC Injury Prevention Unit
Insurance Institute for Highway Safety