Multiple injuries and neck, back and whiplash injuries account for over 80% of all motor claims, Ireland’s Personal Injuries Assessment Board reports. Psychological injuries, arm and leg injuries, head injuries and upper body injuries made up the remainder, with average payouts per claim coming in at €21,707.

The problem appears to persist internationally. Lisa Salisbury, 39, an art director from Connecticut was driving in the autumn of 2006, when she stopped her 2002 Subaru Legacy wagon for workers who had blocked off one lane, unlike the driver behind her who caused the accident.

‘I felt something pop in my neck,’ she recalls. “My head snapped back and then forward when I bounced off the seatback. My shoulder belt actually frayed.” X-rays showed she had fractured parts of two vertebrae and severed a ligament. ‘My doctor told me the bones would heal by themselves but that I’m likely to develop arthritis there. Now, seven months later, I get agonizing headaches whenever it’s about to rain.’

According to the Insurance Institute for Highway Safety (IIHS), which is funded by auto insurers, Salisbury is not alone. Roughly 2 million whiplash claims are filed every year. An estimated 200,000 of those are serious enough to cause long-term medical problems. Taller people are most susceptible, medical experts say.

Despite this, a surprising number of vehicles lack sufficient protection from the whiplash injuries that can result from rear-end crashes, according to crash-test data analysis. Whiplash, occurring to car users every 17 seconds in the U.S., can occur at crash speeds as low as 10 mph. The term refers to the rapid snapping back of a person’s head during a collision which often results in persistent pain and lack of mobility.

Better head restraints and seatbacks would be adequate ways of prevention against this type of injury; yet the problem gets relatively little attention. Car manufacturers do not often provide effective head restraints in all seating positions; and auto-safety advocates concentrate on other dangers, largely because whiplash does not tend to be fatal.

To add the problem, even if some cars have the necessary restraints, most car owners do not know how to properly position them, leaving themselves vulnerable to serious injury.

IIHS crash tests suggest why injuries continue to occur. The IIHS is the only organization that conducts dynamic tests of front seats and head restraints, and makes rear-crash-protection ratings available to the public. Only about one-third of the 175 vehicles for which the institute has overall ratings are rated Good or Acceptable. Nearly a third are rated Marginal, and more than a third are rated Poor.

Since 1969, the US government has passed legislation demanding that all passenger cars have head restraints on outboard front seats. But IIHS tests, which simulate a stationary vehicle being rear-ended by a vehicle of the same weight at 20 mph, have found that even head restraints that are properly positioned do not provide sufficient protection.

“Most of the time what you’ll find is the seatback is too stiff,” explains former General Motors safety engineer and seat designer, David Viano. ‘Ideally, the top part of the seatback, where your shoulders hit it, should be soft and pliable. If you can’t sink into the seat, you rebound off of it during the crash, and that can cause the injury.’

One other issue is that performance can vary from one seat option to another. For instance, the BMW 5 Series with base or “sport” seats is rated ‘Poor’ by the IIHS, but with “comfort” seats it ranks as ‘Acceptable’.

The right design for the seat/head-restraint combination would be difficult to achieve, but crucial to avoid further accidents.