Booster seats get short shrift when it comes to child passenger safety. Even though most parents use boosters for children ages 4-8, how and when they use them makes all the difference. A recent study by Safe Kids Worldwide found parents aren't using booster seats properly. They're also inconsistent about when they use them, and some parents graduate their kids to booster seats and adult seatbelts too soon.
Getting more kids in boosters, and keeping them there longer, is the next frontier in child passenger safety, says Mark Zonfrillo, M.D., head of the Child Passenger Safety Research team at The Center for Injury Research and Prevention at Children's Hospital of Philadelphia (CHOP).
"We've done a really good job at educating parents about rear-facing and harness-based seats, but now we want to ensure that kids don't prematurely graduate to boosters, and don't prematurely graduate to seatbelts only," says Zonfrillo. "We need to raise the bar on child passenger safety and focus on this age group."
How Boosters Protect
Car crashes are the leading cause of death among children in the United States. Booster seats lower the risk of serious injury to children ages 4-8 by 45 percent compared to the use of seatbelts alone, according to CHOP research.
"What a booster seat does is elevate the child and position the lap-and-shoulder belt in the appropriate place to provide the best protection in a crash," says Jessica Jermakian, senior research scientist at the Insurance Institute for Highway Safety (IIHS).
Seatbelt fit doesn't mean just being able to snap on the belt. For a seatbelt to fit properly, the shoulder belt should fit across the midpoint of the collar bone and chest, not riding up on the neck or falling off the shoulder. The lap belt portion should fit low and tight across the lap and not ride up onto the abdomen or hipbone.
Parents can also take their child and booster seat to a child passenger safety event by SafeKids and the National Highway Traffic Safety Administration (NHTSA) to make sure the belts are properly positioned on the child.
Children who are improperly placed in boosters, or who are using an adult seatbelt that doesn't fit properly, are at an increased risk for significant injury, including head injury, and for something called "seatbelt syndrome." The syndrome is a constellation of injuries, including severe abdominal wall bruising, abdominal injuries and lumbar spine fractures, explains Zonfrillo, an emergency room doctor who has seen such cases.
There is a major problem with all child passenger restraint systems, experts say: the premature transitioning from one restraint to another. Safe Kids found that nine out of 10 parents move their child from a booster to an adult seatbelt before the child is big enough to be properly restrained by a seatbelt.
"There is a tendency for families to transition their children too soon to the next restraint," says Jermakian. "We'd like to see them using harness restraints for longer, using boosters for longer."
Best Guidelines To Follow
Parents should not rely solely on state seatbelt laws, which are often based on a child's age, or age and weight, to determine if their child is ready for an adult seatbelt. "The laws and legislation often lag in terms of catching up with standard best practice," Zonfrillo says.
The American Academy of Pediatrics (AAP) and SafeKids Worldwide both recommend that children remain in booster seats until they are at least 4 feet 9 inches tall and between 80 and 100 pounds. AAP guidelines also say most children will be ready for an adult seatbelt when they are between the ages of 8 and 12.
Regardless of weight or age, a child's height remains the most important proxy for seatbelt fit, Zonfrillo says.
"We are seeing an obesity epidemic in this country, so children can certainly be much heavier but still not be tall enough for the seatbelt to fit," he says. "The belt is really created for an adult, and when you try to translate that to a child in the event of a crash, you can have the forces distributed where they shouldn't be."
Zonfrillo advises parents to use a harness seat with the highest weight limit, instead of transitioning to boosters prematurely. "We technically would all be safest in a harness," he says. "That's why racecar drivers wear harnesses. They are the safest form of restraint." Several harness-equipped convertible car seats and toddler booster seats have maximum requirements of 80-90 pounds, according to ratings by Consumer Reports.
Choosing a Booster Seat
Booster seats come in both high-back and backless versions. CHOP research shows that both versions perform equally well in crashes. For households with more than one child, that's important to note, says Zonfrillo. It may be easier to fit backless boosters next to traditional seats without worrying about compromising safety.
Backless boosters may also eliminate the social stigma associated with riding in a high-back version.
"Kids can become self-conscious about being in what they consider a baby seat," Zonfrillo says. "If they are in a backless booster with the belt on and they get picked up from school or soccer practice, no one is going to see it."
Unlike forward-facing car seats, which are attached to the vehicle with either a bottom tether or top LATCH system, booster seats are not attached to the vehicle. The vehicle's seatbelt functions as the restraint, securing both the booster seat and the child. That's why belt fit is so critical.
IIHS evaluates new booster seats on the market for proper lap and shoulder belt fit. A Best Bet rating means the boosters provide good belt fit in almost any car, minivan or SUV. Other ratings include Good Bet, Check Fit and Not Recommended.
"We try to take a lot of the guesswork out of the equation for parents by doing our booster ratings," Jermakian says. "There are booster seats that achieve our top rating that range anywhere from $20 to several hundred dollars, so there's a wide range for parents to choose from."
When IIHS first began evaluating boosters in 2008, only 10 of 41 models received a Best Bet rating, and 13 landed on the Not Recommended list. Many car seat manufacturers now work closely with IIHS to create booster seats that meet IIHS's rigorous standards for seatbelt fit.
Where a booster seat received the lowest rating, the manufacturer cited that the seats still meet federal standards for crash-worthiness. Here, too, say experts, a seat that just meets government standards isn't necessarily one that's the safest.
"Any seat that is available on the market meets the minimum requirements that are set out by the federal government. And that's exactly what they are: minimum requirements," Jermakian says. "Even though these seats pass the dynamic tests the federal government requires, many of the booster seats in our studies had not done a good job of providing a proper belt fit, and we know that proper belt fit is critical to reducing injuries."
Consistency and Carpooling
Booster seat and seatbelt use can be less rigorous when carpooling comes into play. The booster-seat study by Safe Kids Worldwide found one in five parents "bend the rules" when carpooling, allowing their children or other children to ride without a booster seat and sometimes without seatbelts.
"The message needs to be consistent," Zonfrillo says. He advises parents to have up-front, matter-of-fact conversations about using booster seats with friends, grandparents and caregivers who may be transporting their child. If you're transporting someone else's child, he says, don't be shy about saying that you think the child still needs a booster.
"You can frame it in a way that says, 'This is something I recently learned and my son still needs to be in a booster seat, and your child might, too,'" Zonfrillo says.