This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Review our Privacy and Cookie Notice for more details. X

Preventing Whiplash

Preventing Whiplash

By Jeff Youngs, February 24, 2012
If you've ever been involved in an automobile accident, you more than likely know the feeling of waking up the next day with a nagging soreness in your neck. That pain is known as whiplash, and is a common injury following an accident, especially a rear-end collision.

While it may be common, whiplash is an injury that can be far less severe (and sometimes prevented entirely) depending on the type of headrest in your vehicle and whether it is properly adjusted. Indeed, the term headrest is really quite misleading. Headrests are not designed for resting your head; its true purpose is to protect your head from moving too far backward in a rear-end collision. In other words, it's there to reduce whiplash. In fact, safety experts and automakers instead refer to them as head restraints.

The Insurance Institute for Highway Safety (IIHS,, one of two groups in the United States that provide consumers with crash test ratings, began studying the effectiveness of head restraints in 1995. At that time, only five models were designated "Good" (the Institute's highest of four scores) with regard to their head restraints. To determine the ratings, the Institute uses a static test that measures a crash test dummy's head position in relation to the head restraint; what the Institute refers to as head restraint "geometry." Since that time, head restraints have improved dramatically. For 2004 model-year vehicles, the IIHS reported that 80 percent of models had "Good" or "Acceptable" ratings for head restraints.

Recently, it became apparent to IIHS that a dynamic test would provide additional details on the effectiveness of head restraints. As a result, it developed a test in which the seat and a crash test dummy are propelled forward on a sled to simulate a collision. They used this test in conjunction with the static test they had been using for the previous decade. Interestingly, the same models that scored well in the static test did not perform well in the dynamic test. In fact, 54 of 97 models included in the Institute's 2006 dynamic tests were rated "Poor" (the Institute's lowest score), and many of them are some of the best-selling models on the market. Additionally, nine models among this group that were previously rated "Good" and 21 that were previously rated "Acceptable" in their static geometry test performed poorly in the dynamic test because the head restraint did not meet the back of the head quickly enough during the collision.

Real-world research

In addition to conducting tests in its research facility, IIHS has also studied the effectiveness of head restraints in real-world crashes using claims data provided by insurance companies. The study assessed old and new seat/head restraint designs in a variety of models. Automakers took three different approaches to the whiplash problem: improve the geometry of the head restraint (so it was closer to the occupant's head and positioned in the center of the seat); design active head restraints (that move forward to meet the head as it moves backward in a rear-end collision); and redesign the seatbacks themselves (the seat moves to support the body).

Of all the designs studied, the IIHS determined that the key to reducing whiplash injury is to keep the occupant's head and torso moving together. The results of the data suggested a reduction in injury claims regardless of what type of approach was used.

Seeing results

Although the National Highway Traffic Safety Administration (NHTSA, a government organization, does not rate head restraints, the agency sees value in the research conducted by IIHS and individual automakers. Acknowledging the role that seat and head restraint design plays in reducing whiplash, NHTSA has implemented a new regulation that will require front-seat head restraints to be located closer to the back of the head and centered vertically behind it. If head restraints are adjustable, they must lock in place after positioning. These same rules will apply to rear-seat head restraints, if they are installed on a vehicle (however, the rules do not require automakers to equip vehicles with rear-seat head restraints). The regulation goes into effect on all passenger vehicles manufactured after September 1, 2008. NHTSA estimates that whiplash injuries will drop by 17,000 annually when all new vehicles meet this requirement.

Protecting yourself

The following tips can help you prevent whiplash during a collision:

Recline your seatback a little less. A seatback that is more upright means the upper part of the seat and head restraint are more likely to be closer to your head, reducing your chance of injury.

Adjust your head restraint. About 80 percent of all passenger vehicles in the United States have adjustable head restraints, yet studies indicate less than 10 percent of occupants adjust them properly. To adjust your head restraint, raise it up so it is at least to the top of your ears. If your head restraint can be tipped forward, move it closer to the back of your head. Both driver and passengers should make these adjustments.

Check the head restraint ratings when vehicle shopping. When it comes time to buy a new vehicle, assess the detailed IIHS head restraint ratings at under the Vehicle Ratings tab. Use these ratings when comparison shopping, just as you would use any other crash test information.
Untitled Document

Subscribe to J.D. Power Cars Newsletter

* indicates required

View previous campaigns.