The future may see a lot fewer serious whiplash injuries, thanks to a fresh crop of front-seat head restraints hitting the market that comply with a new federal safety standard.

But like some notorious past examples of safety features that never gained public acceptance, early evidence says vehicle buyers think the new whiplash-mitigating restraints — the less-expensive, “fixed” variety — are a genuine pain in the neck.

Federal Motor Vehicle Safety Standard 202a mandates all vehicles made after Sept. 1 to have front seats with head restraints (the industry deplores the term “headrest”) that reduce the potential for whiplash — extreme rearward “rotation” of the head — in low-speed crashes. Rear seats with head restraints will have to comply by 2010.

How this new level of protection is achieved, particularly in respect to the age-old bugaboo of cost, is where the hassle starts.

A number of more expensive vehicles already come equipped with advanced active restraints that move forward during a collision to prevent the head from rotating too far rearward.

For lower-priced vehicles, the answer is a new fixed head restraint that satisfies a set of geometric criteria relating to the position of the head in relation to the restraint.

In effect, a new FMVSS 202a-compliant fixed head restraint has to be at least 29.5 ins. (75 cm) above the occupant's hip point if the restraint is height-adjustable, and a towering 31.5 ins. (80 cm) for non-adjustable head restraints.

As much as 4 ins. (10.2 cm) higher than before, some fixed head restraints fulfilling this measure look like something you got paddled with in grade school.

What's worse is the mandate a fixed head restraint be positioned no further than 2.2 ins. (5.6 cm) from the back of the head. This meager 2.2 ins. of “backset” is where the real trouble lies.

It turns out most people can't deal with a head restraint looming so closely. And due to a lot of variables, some fixed restraints are constantly in contact with a front-seat occupant's head.

One car buyer recently said his family nixed a particular vehicle because they didn't like the seats. But upon further questioning, it turns out it was the new 202a-compliant head restraints that killed the deal. “The thing was literally pushing my head forward,” the buyer says.

Matt Parkinson is a professor of engineering design and mechanical engineering at Penn State University. In association with PSU's OPEN Design Lab, Parkinson has done extensive research into the adoption of the new restraints.

Parkinson was appalled to discover his own parents had reversed the head restraints on their new car to win some relief from the mild pressure of the restraints on the back of their heads. “People just aren't comfortable with things that close to their heads,” Parkinson says, adding, “It's almost impossible” for 202a-compliant fixed restraints to meet the standard and not cause discomfort.

“There's a lot of anecdotal evidence” that the new head restraints are the source of consumer discontent, he says, “and we expect it to get worse.”

Parkinson says because of factors such as variability in seat design, manufacturing, the way the seat is installed and even the test for 202a compliance, seat manufacturers design the restraints to be much closer than the 2.2-in. maximum.

“You've got to design to something like 30 mm (1.2 ins.),” he says. Stack up all these variables — including your height and how much you recline your seatback — and the result is a new whiplash-mitigating device that can touch the head constantly.

A likely howl of customer complaints could be music to the ears of seat suppliers. Since the standard's adoption, suppliers have advocated the active head-restraint solution because it was expected fixed restraints would be annoying.

“The static (fixed head restraint) solution will lead to unhappy consumers,” Gerald Locke, seat-making giant Lear Corp.'s director-safety engineering, told Ward's in fall 2006.

That mainly will be women, those of short stature and those who prefer to sit more upright, with minimal seatback angles.

“We've had the same anecdotal information from our customer base,” says Dimitri Moustakeas, Grammer Automotive AG's vice president-sales and engineering for North America.

Every major seat supplier says active head restraints that pivot forward are the only solution that can truly avoid alienating customers. Because the active devices move closer in a crash, they can reside at a much less intimidating distance from the head and do not have to be unusually large.

Volvo Cars and Saab Automobile, the two Swedish auto makers whose brand reputations are linked to enlightened safety advances, offered whiplash-mitigating technology long before FMVSS 202a was approved in 2004.

Volvo's S80 sedan in 1999 was the first to offer the company's WHIPS (WHIplash Protection System) — not an active head restraint, per se, but a design that pivots the entire seatback down and rearward in a rear impact. The WHIPS system now is standard for all Volvo vehicles.

And all Saabs, save the 9-7x SUV, now feature the Saab Active Head Restraint, which first was used in 1997 for the 9-5 sedan and came to the U.S. for '99 models.

A potential bonanza awaits suppliers as seats with less expensive, fixed 202a-compliant restraints appear to be winning no friends in the showroom.

But the climate is difficult: The U.S. auto market is trending downward, and auto makers need to keep program costs, as well as sticker prices, down. Suppliers decline to quote the price difference between the two approaches, but some say it will be difficult to deploy active restraints on down-market vehicles.

Johnson Controls Inc. offers some hope in the form of its new riACT (rear impact ACTive technology) design, which it says can work well for entry-level vehicles.

Scott Donegan, JCI's director-product & business development, says the riACT system has great potential for entry-level applications because of its modular design.

A lower-cost version of riACT is triggered in a rear-end collision when the occupant's pelvis strikes a plate in the backrest, which in turn pulls a cable that springs the restraint forward, closer to the head.

Donegan points to this version of riACT's fitment in the European Kia Cee'd, an inexpensive sedan. The body-weight-activated version of riACT deploys somewhat more slowly than the version that is triggered by a signal from a crash sensor.

This variant is fitted in several upmarket models, but Donegan says it is a fine, cost-mitigating alternative to fixed head restraints. But JCI expects consumer complaints about fixed head restraints in J.D. Power and Associates satisfaction surveys — another issue that may drive active technology.

Donegan says JCI has more than a dozen vehicle programs ready to deploy the riACT technology for '09, and the company says many auto makers that originally schemed to use fixed restraints to comply with 202a now are backing the active solution, despite the increased cost.

Active head restraints “will be going into lower-end vehicles relatively soon,” agrees Grammer's Moustakeas.

He says Grammer, which currently supplies active head restraints for several European models such as the Mercedes C-, M- and R-Class and the BMW 5-Series, is working with at least one U.S. auto maker on a '10 program.

The potential liability from irritating customers will be the main driver in increased use of active restraints, but customer outcry may figure into the issue in another way. PSU's Parkinson reminds a few unpopular — and in some cases, entirely annoying — safety mandates of the past have been changed, altered or simply left behind as better solutions surfaced.

Who can forget some of the more ridiculous passive-seatbelt solutions (those “mouse” belts, circa 1987) and the infamous ignition interlock for safety belts in the mid-1970s?

Also favoring active head restraints may be increasingly influential crash-test ratings. In the U.S., the Insurance Institute for Highway Safety rates seats for many vehicles. A scan of the listings for several vehicles shows seats with some type of active head restraint invariably score the top rating of “good.”

Given the early and largely disfavorable feedback for new-age fixed head restraints, Parkinson believes active devices effectively will become standard equipment if FMVSS 202a remains. With fixed head restraints, Parkinson says the only real way to assure customers are happy is to return their space with active head restraints.

New Rules for Head Restraints http://wardsautoworld.com/ar/auto_new_rules_head