- The Washington Times - Friday, November 8, 2002

The Insurance Institute for Highway Safety has found that some new designs for head and seat restraints reduce neck injuries by almost half. The jury is still out on others. This is a first look at real-world rear-end crashes.
The National Highway Safety Traffic Administration estimates there are 800,000 neck injuries each year in rear-end collisions. Although head restraints have been required in cars since 1969 to help protect against whiplash injuries, safety researchers at the institute, which is funded by the insurance industry, has found most weren't high enough or close enough to the back of the head to restrain the head and be effective.
There has been improvement, however. In 1995, when the institute first began evaluating head restraints, only 7 percent were rated either "good" or "acceptable" on a scale that includes ratings of "marginal" and "poor." That number has risen to 54 percent.
These ratings are not based on crash tests but are done by measuring the height and distance between the back of an occupant's head and the front of the head restraint. Ideally, a head restraint should be at least as high as the top of a person's ears and as close to the back of a person's head as possible. That is so the restraint can reduce the sudden motion of the head in relation to the torso.
Research indicates that whiplash occurs when a rear impact causes the torso to be pushed forward while the head and neck lag behind. Without support from a head restraint, the head and neck snap backward and then whip forward.
Automakers have taken different approaches to improving head restraints in their vehicles, and the insurance institute looked at four designs of seats and head restraints by reviewing 2,641 property damage liability claims for rear-end crashes.
The study compared claims for certain models with the new designs with claims for similar models before the new designs were introduced.
Saab's "active" head restraint uses a mechanism in the seat back to push the head restraint up and toward the back of the head in a rear-end collision.
This design is also used in some General Motors and Nissan models.
The new survey found a 43 percent reduction in neck-injury claims rates in the following models with the active restraint compared with earlier models without the active restraint: Buick LeSabre, Infiniti QX4 (four-wheel-drive model) and Q45, Pontiac Bonneville, Saab 9-3 and 9-5.
One of the easiest ways to improve head restraints is to make them taller and closer to the backs of most people's heads. Ford has done this in the 2000 to 2002 Ford Taurus and Mercury Sable models.
The insurance institute found an 18 percent reduction in neck injuries in these models, but warned there were not enough claims to make the findings statistically significant.
Two other automakers have focused on seat back design in an attempt to reduce whiplash injuries.
Volvo uses a specially designed hinge at the bottom of the seat back, allowing it to move rearward to reduce the forward acceleration of the torso.
The survey of insurance claims for the Volvo S70 found a 49 percent reduction in neck-injury claims with the new seats, although there were not enough claims to make the finding statistically significant.
Toyota's seats allow a person's body to sink farther into the seat back during a rear impact. The vehicles in the study, the Toyota Avalon and the Lexus LS 430, showed a slight increase (15 percent) in neck-injury-claim rates, but again the insurance institute said there were too few claims for the results to be statistically significant.
Toyota takes exception with the findings. "This is a study of change in protection, rather than an analysis of overall protection. Our internal data show our seat performs as well as or better than the other systems that they tested. We already had very good seats," said Toyota spokeswoman Martha Voss.
Also, it is a very small sample and based on insurance claims that are self-reported, Miss Voss said.
The public should have more definitive information on these systems when the insurance institute switches from measuring head restraints to crash-testing these systems early next year.


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