Only 22 of 75 vehicles tested in a simulated rear crash at 20 mph received the top score of good from the Insurance Institute for Highway Safety.
Overall, reported The Early Show consumer correspondent Susan Koeppen Thursday, 60 percent of cars tested fall short of giving you the protection you need. Almost two out of three models were rated marginal or poor.
Several 2007 vehicles got the lowest score of poor in the tests. Those vehicles include: the Acura TSX, some versions of the BMW 5 Series, Buick Lacrosse and Lucerne; Cadillac CTS, STS and DTS; Chevrolet Aveo, Pontiac Grand Prix, Honda Accord and Fit; Hyundai Accent, Infiniti M35, Jaguar X-Type, Kia Rio, Mitsubishi Galant, Toyota Avalon, Toyota Corolla, and the Suzuki Forenza and Reno.
The institute estimates that neck injuries account for 2 million insurance claims annually, costing at least $8.5 billion.
Neck injuries are the most common injuries reported in car crashes, she added, Koeppen added.
For details from the Institute on the results, click here.
Among the top vehicles for head protection, according to the Institute's testing, were the Audi A4, A6 and S4; Chevrolet Cobalt, Ford Five Hundred and Mercury Montego; Hyundai Sonata, Jaguar S-Type, Kia Optima, Mercedes E-Class, Nissan Sentra and Versa; Saab 9-3, Subaru Impreza, Outback and Legacy; Volvo S40, S60, S80; the Honda Civic 2-door and 4-door versions and some versions of the Volkswagen New Beetle.
"People think of head restraints as head rests, but they're not. They're important safety features," said Adrian Lund, the institute's president. "You're more likely to need the protection of a good head restraint than the other safety devices in your vehicle because rear-end crashes are so common."
The federal government will require better positioning of head restraints by the 2009 model year, Koeppen pointed out.
Bill Kwong, a Toyota spokesman, said the test does not take into account other aspects of a vehicle's response to a crash under normal driving conditions, such as the vehicle's structure, rear crumple zones and bumpers.
"We feel our in-house procedures are good predictors of how it will perform in the real world," Kwong said.
General Motors said it designs head restraints "to meet a variety of driver sizes rather than focusing on a single set of metrics. Head restraints are part of the integrated approach to occupant protection in all GM vehicles."
The vehicles were tested on a crash simulation sled, replicating the forces in a stationary vehicle that is struck in the rear by a similar vehicle at 20 mph.
Vehicles got a higher rating if the head restraint contacted the dummy's head quickly and the forces on the dummy's neck and the acceleration of the torso were low.
The tests also consider the height of the restraint and its horizontal distance behind the back of the head of an average-size man.
The institute says a head restraint should extend at least as high as the top of the ears of the tallest motorist and be placed close to the back of the head so the restraint can support it early in a rear-end crash.
Models that received poor or marginal scores for the restraint design were given poor overall marks because they could not be positioned to protect many motorists.