Ask Joe Mechanic - Anti-Whiplash Head Restraints

Anti-whiplash head restraints were first introduced in 1999. Whiplash is the sudden jerking motion of the head in a rear end collision. This injury is often minor to mild and will go away after a few days or weeks. However, about 10-15 percent of whiplash incidents will cause long term or permanent injury and the pain and effects can be debilitating.

            Saab was the first manufacturer to introduce an active anti-whiplash headrest system as standard equipment across their entire product line. Although the company obtained patents for its system, they offered the technology to any other company that wanted to use it as they felt the importance of limiting these injuries was more important than the financial gain that they could obtain. A little later the same year, Volvo introduced their own system called WHIPS. These are the two basic systems that are in use, and while they are both doing the same job, they differ in design and operation.

            The Saab system is such a simple system that it is hard to believe that it took so long for someone to introduce it. The headrest consists of the outer headrest assembly, which is attached to an arm that is anchored in the upper part of the backrest. The lower end of the arm is attached to a flat plate that is located in the lower center of the backrest.

When the automobile is struck in the rear, the person’s body will be pressed into the seat by the impact. That pressure pivots the headrest forward to contact the back of the head, preventing the rearward snapping motion that causes the injury. As soon as the impact is over, the headrest returns to its original position and requires no repairs or resetting. The other plus to this system is that in the event of multiple impacts, it will activate upon each impact and be ready for the next.

            The Volvo system, WHIPS, is somewhat different. In the event of a rear-end collision, the seatback moves with the occupant while the headrest remains rigid. A WHIPS seat also has a plate in the backrest, but in this design, it actually absorbs some of the energy of the impact. This occurs while the bottom of the backrest pivots to allow movement of the hip joint, and moves rearward to absorb additional energy. The one major difference with this system is that it does require repairs to the seat to restore it to its correct operation and seating position.

            Studies of vehicles with anti-whiplash protection systems, sustaining rear impact collisions by various testing agencies have shown a reduction of short-term whiplash injuries by between 25-40 percent.  However, even more important is the effect on long-term whiplash injuries, a reduction of a staggering 54 percent. When you consider the high costs of rear impact injuries and the pain that the victims suffer, this is a very significant reduction in cost and in pain and suffering.

The most important thing to remember if you own a vehicle with an anti-whiplash protection system is to keep your headrest properly adjusted. When I was selling Saabs a number of years ago, we were instructed to share and demonstrate to the customer the proper alignment of the headrest. That positioning is to have the horizontal centerline of the headrest even with the person’s ears. In this position, the system will offer maximum protection.

           

The improvements in headrest technology have been impressive. In 1995, the National Institute for Highway Safety gave only 3 percent of vehicles a good rating at reducing head/neck injuries. By 2005, just ten years later, that number had grown to 51 percent.

            I can personally attest to the effectiveness of the Saab system.   About two months ago, my family and I were traveling to Atlantic City in our 2001 Saab 9-5SE. On Route 42, traffic was stopping in front of us. While at a complete stop, a young girl, talking on her cell phone, rear-ended us without apparently braking at all. Our Saab was totaled; we were pushed into two other cars immediately in front of us, and our vehicle was shortened about six to eight inches. The police and the insurance appraiser both estimated impact at about 50 MPH. The only injury suffered by the four people in our car was a sore left shoulder and arm by my wife. These systems do work, and if you are thinking about a new vehicle, it is something well worth factoring in to your buying decision.