A noted automotive-safety organization says some car booster seats do such a poor job of protecting kids that it can't recommend them.

The Insurance Institute for Highway Safety tested 41 booster seats and found that 13 of them don't do the one thing they're supposed to do: elevate children so that safety belts designed for adults are in the right position to restrain kids during a crash.

The independent, nonprofit organization contends that the evaluation it conducted with the University of Michigan Transportation Research Institute is the first to tell consumers how well boosters sold by U.S. retailers improve safety-belt fit for children.

Experts say well-designed boosters route belts across boney portions of a child's body, such as the pelvic bones and the middle of the shoulder, as opposed to more vulnerable areas such as the abdomen and neck.

Researchers assessed two types of boosters, backless and high-back, under conditions representing a range of 2001-2006 model vehicles. Some high-backs convert to backless, and some boosters, marketed as combination seats, can be used as child restraints.

The insurance institute said that because of its tests, it can't recommend the following boosters: the high-back Compass B505, Compass B510, Cosco/Dorel Traveler and Evenflo Big Kid Confidence; the backless Safety Angel Ride Ryte; and the combination Cosco/Dorel Alpha Omega, Cosco/Dorel (Eddie Bauer) Summit, Cosco Highback Booster, Dorel/Safety 1st (Eddie Bauer) Prospect, Evenflo
Chase Comfort Touch, Evenflo Generations, Graco CarGo Zephyr and Safety 1st/Dorel Intera.

"These boosters may increase restraint use by making children more comfortable, but they don't position belts for optimal protection," said Adrian Lund, president of the insurance institute.

In a statement, Evenflo said that it conducts extensive seat testing and called the study "misleading as it fails to consider the real world use and performance of the seats tested." The company said it had sold more than 4 million of the seats cited by the study and "we are not aware of a single incident in which a child was injured as a result of an improper fit."

Dorel Juvenile Group said it welcomed the opportunity to review the evaluation, and Graco Children's Products responded that "safety is always a top priority, and nothing is more important than the well-being of the children who use our products."

The insurance institute, supported by auto insurers and best known for conducting crash tests of new vehicles, identified 10 "best bets," boosters that it says are most likely to position seat belts correctly.

Among them are three backless seats: Combi Kobuk, Fisher-Price Safe Voyage and Graco TurboBooster. Six are high-back: Britax Monarch, Britax Parkway, Fisher-Price Safe Voyage, LaRoche Bros. Teddy Bear, Recaro Young Style and Volvo booster cushion. The final booster on that list is the combination seat Safeguard Go, when it's used as a backless booster. Combination seats convert to boosters by removing their built-in harnesses.

The insurance institute also identified five "good bets": the high-back Combi Kobuk, Graco TurboBooster and Safety Angel Ride Ryte, as well as the combination Recaro Young Sport and Safety 1st/Dorel Apex 65, when used as high-backs.

The booster seats included in the evaluation ranged in price from about $20 to $200, but price, it turns out, didn't necessarily correlate with performance.

Some child-safety experts said they hope the research doesn't prompt any parent to stop using a booster seat. Children involved in crashes are less likely to suffer injuries if they're in a booster, even a less-effective model, they said.

Looking for more guidance?

Go to www.safekidscentralohio.org, the website of Safe Kids Central Ohio, a coalition of public and private organizations working together to prevent injuries to children. The site contains the names, locations and phone numbers of more than a dozen local organizations that offer free car-seat and booster checks.