A rear-end crash occurs every 17 seconds in the U.S. But many cars, especially those made before 2009, offer inadequate protection from the whiplash injuries that can result. Whiplash refers to the rapid snapping back of a person’s head during a collision, which hyperextends the neck and damages nerves and ligaments, often resulting in chronic symptoms such as persistent pain and lack of mobility. It can occur at crash speeds as low as 10 mph.
According to the Insurance Institute for Highway Safety (IIHS), which is funded by auto insurers, neck sprains and strains are the most frequently reported injuries every year. Taller people, especially women, are most susceptible, medical experts say.
However, head-restraint effectiveness has improved dramatically in recent years. The IIHS started a rear-crash program in 2004 and in 2005 nearly half the front head restraints were rated Poor and 12 percent were Good. By 2014 none rated Poor and 95 percent were Good
Federal standards were tightened in 2005, setting minimum heights for restraints and limiting the allowable distance between the front restraint and a person's head. The phase-in was completed for the 2009 model year.
Problems remain in the rear
While front-seat head restraints have gotten a lot better, rear-seat restraints often get short shrift. Although the situation has improved in recent years, many cars’ rear seats have less sophisticated head restraints than the front and have no restraint at all in the center rear.
We measure the height of the head restraints in all the cars we test and make sure they can stay fixed at least 29.5 inches above the seat cushion. If a restraint isn’t high enough to be effective in preventing whiplash, we note that in our test reports.
More vehicles are being made with effective, adjustable head restraints in all rear positions. But some, especially tall fixed restraints, create another problem, making it difficult for the driver to see out the rear windows. To redress that, some restraints can retract into a recess in the seatback or can fold out of the way when the rear seat is unoccupied. We prefer the type that folds forward or protrudes into the seating area, because they force rear passengers to deploy them before they can get comfortable. Volvos and Mercedes-Benz vehicle have those types.
Good positioning is critical
Whatever car you drive, you’ll get the maximum whiplash protection from a head restraint that’s properly positioned. To work well, the top of the restraint should reach at least as high as the top of your ears, and preferably the top of your head, and be relatively close—4 inches or less—to the back of your head.
Adjustable restraints are the most common type. They can be raised or lowered to the proper height, and many can be tilted toward or away from the head. But they’re only effective if occupants take the time to adjust them properly. Many people don’t, which increases their risk of serious injury.
More and more automakers have introduced "active" head restraints, which automatically move up and forward to catch a person’s head in a rear crash. Those are usually effective, but there’s no guarantee "It’s not just the head restraint but the seat architecture that determines what’s going to happen," says Adrian Lund, president of the IIHS.
Next steps in head restraints
While the federal government upgraded its head restraint rule in 2005, with the phase-in complete for the 2009 model year, Consumers Union, the publisher of Consumer Reports, believes the new rule still falls short. For instance, it doesn’t require rear-seat head restraints but only says that if restraints are included for the outboard positions they must meet a height requirement. And center-rear head restraints still aren’t required at all. CU would like to see head restraints mandated for all rear seats, and that the back-set (the distance between the restraint and a passenger’s head) should be limited as well.