ARLINGTON, Va. — The designs of head restraints in an increasing number of passenger vehicles are improving so that many occupants are better protected from whiplash injury in rear-end crashes. The Insurance Institute for Highway Safety began rating the geometry of head restraints in 1995, finding only 3 percent of vehicles had good head restraints, while those in 82 percent of new passenger vehicles were poor. Now these proportions have changed — in the 2003 model year 45 percent of passenger vehicles had head restraints rated good (see attachment). At the same time, the percentage of 2003 model vehicles with poor restraints had dropped to 10.
Improvements in head restraints:
percentage of head restraints rated good vs. poor,
based on geometry, by model year
"It used to be that unless you were short you'd have trouble finding a vehicle with head restraints that extended high enough to protect you. Now automakers are making improvements so that in many vehicles even taller people can position the head restraints where they need to be to protect the neck from being injured in a rear-end crash," says Institute chief operating officer Adrian Lund.
A well-designed restraint, in concert with the seatback, can reduce the risk of whiplash injury by reducing the differential motion of an occupant's head and torso in a rear-end crash. The necessary first step toward accomplishing this is a head restraint that's positioned high and as close to the back of the head as possible. Head restraints with poor geometry cannot be positioned this way for many occupants, so they cannot begin to prevent whiplash injuries.
Occupants need to adjust head restraints
Even as automakers improve head restraint geometry, many motorists aren't reaping the full benefits. The restraints in about four of every five passenger vehicles have to be manually adjusted upward to protect many occupants. But such restraints often aren't adjusted. They're left in the lowest position, where they cannot provide many occupants with any protection against whiplash in rear-end crashes.
Institute researchers observed the positions of driver head restraints in more than 7,000 passenger vehicles at intersections in the Washington, D.C., and Charlottesville, Virginia, areas. When the restraints were positioned at or above drivers' ears, they were assumed to be high enough to protect the neck from whiplash in rear impacts. Across both locations, 60 percent of the observed head restraints of all types were high enough to provide protection. Among the adjustable designs that had been left in the unadjusted (lowest) position, fewer than half (48 percent) reached drivers' ears.
Percentage of head restraints positioned at or above drivers' ears
|By restraint type:|
|83%||adjustable restraint (adjusted upward)|
|48%||adjustable restraint (unadjusted)|
|63%||fixed head restraint|
|By gender of occupant:|
|By vehicle type:|
|61%||cars and minivans|
Seventy-eight percent of the observed head restraints were adjustable designs, and among these about 1 in 3 had been adjusted upward. This week the Spinal Injury Foundation is launching "Save Your Neck," a campaign to encourage motorists to adjust their head restraints properly. The campaign will involve sites at which head restraint adjustments will be checked.
Federal government lags behind
"Federal safety requirements for head restraints are the same today as when head restraints first were mandated in 1969. Automakers are improving head restraints, but it could have happened sooner with better requirements," Lund points out. "The federal standard was weak to begin with when it first took effect almost 35 years ago, and now it's woefully inadequate. It lags way behind requirements in Europe. As long ago as 1974 the National Highway Traffic Safety Administration did propose upgrading the standard but then let the matter drop. The agency later began the rulemaking process over again and proposed a substantial upgrade in 2001, but once again the task hasn't been completed. More than two years have elapsed since the last proposal for upgrading this standard, and there's no final rule. It keeps being put off and then put off again. Where is it?"
With or without federal action, head restraints already are being improved — and geometry isn't the only aspect that's getting better. Some automakers are designing advanced head restraints that actively position themselves closer to occupants' heads or adjust seat stiffness to control torso movement in rear-end crashes. Some of these designs have been found to reduce neck injuries in real-world crashes.