Big Kids, Boosters, and Back Seats: How This Simple Combination Can Prevent Serious Injuries in Motor Vehicle Collisions

If your children are anything like mine, they start insisting they are far too old or too big to ride in a booster seat when, in reality, they’re still too small to ride safely without one.

“But my friends don’t ride in them,” and “I’m not a baby anymore,” are common arguments that kids love to use to try and sway a parent’s judgement. Some booster seat manufacturers may even pressure parents further by labeling their product as only necessary for children up to a certain age or weight. After hearing these points often enough, you may be tempted to believe them.

Here’s the catch: no specific age or weight limit can measure safety benefits of a booster seat—it’s all about the proper fit of a child’s seat belt.

The team at partnered with the Virginia Highway Safety Office, Eastern Virginia Medical School, Children’s Hospital of the King’s Daughters, and Portsmouth Fire & Rescue to create this powerful video that demonstrates the importance of booster seats for “big kids”:

How does a booster seat keep my child safer in an accident?

Booster seats elevate children so that a car’s lap and shoulder belt will fit properly. A proper fit of the vehicle’s integrated seat belt is one in which the lap belt rests across the child’s hips and the shoulder belt rests across the shoulder and chest, not against the neck or behind the child’s back. No matter what their age or weight, or how much they argue to the contrary, a child cannot achieve the correct fit of an integrated seat belt without the aid of a booster seat until they are at least 4’9” (145 cm) tall.

Children who are under 4’9” and not elevated by a booster seat run the risk of a vehicle’s integrated safety belt riding up above their hips and onto their abdomen. If they’re involved in a collision with a seat belt in this position, the sudden pressure of the belt itself can cause severe internal injuries. Shoulder belts that are repositioned behind a child’s back or under an arm to try and accommodate for an uncomfortable and improper fit can result in catastrophic head and spinal damage in a crash.

The elevation provided by booster seats is crucial to achieving the maximum benefit from your car’s safety belt system.

How do I know if they’re too small for a booster seat?

You know that your child isn’t too big for a booster seat, but how can you tell if they’re too small? If you’re uncertain after trying out the fit of your car’s seat belt, then a harness seat is a better choice than a booster. Younger children whose pelvic bones have yet to develop the ridges needed to help a vehicle’s integrated seat belt stay in the proper position require the additional protection provided by a harness seat.

Though booster seat manufacturers market their products for children as young as 3 years old or 30 pounds, the National Highway Traffic Safety Administration (NHTSA) and the American Academy of Pediatrics (AAP) both recommend a safety seat with a five-point harness for children between the ages of 3 and 7. These harnesses help to prevent young children from sliding under traditional three-point safety belts in a collision, and they also help to reduce the severity of injuries by spreading the force of an impact over a wider area of the child’s body, reducing localized trauma.

If your child is 7 years old and has not yet outgrown the belt length of a harness seat, they should continue using it. The five-point harness is still their safest option when they surpass 7 years as long as they still comfortably fit the seat.

Does a booster mean my child is ready for the front seat?

According to NHTSA, children under age 13 should always ride in the back seat to prevent impact injuries from air bags. A child who is elevated by a booster seat and who has a properly-fitted safety belt is still vulnerable to the damages caused by the force of air bag deployment. To help reduce injuries in a collision, the back seat is the safest place in the vehicle.

If you have questions about the proper way to secure a harness seat in your car, how to use the seat belt guide on a booster seat, or would like hands-on guidance and an expert opinion of the fit of your child’s safety belt, you can visit your local police or fire station for assistance. You can also find a National Child Passenger Safety Certified Technician (CPST) and child seat-fitting stations though the CPST web directory.

Additional harness seat and booster seat installation help is available from NHTSA Parents Central.