May 18, 2022

Transitioning to seat belts too early can result in serious trauma.

Transitioning a child from a car seat or booster seat to a standard seat belt before they’re physically ready can cause pediatric spinal injuries and damage to internal organs in the event of a crash. In recent years, Vanderbilt University Medical Center has seen an uptick in motor vehicle accidents resulting in serious back injuries to kids caused by premature seat belt use.

Parents should transition their child to a booster seat if their child has outgrown the manufacturer’s recommendations for their car seat. Vanderbilt offers free monthly car seat 101 classes and car seat check events if you’re unsure.

“It’s important that you spend the time to understand exactly what device your kid needs to be in,” said Craig Louer, M.D., a pediatric orthopaedic surgeon with Monroe Carell Jr. Children’s Hospital at Vanderbilt. “And just because you have that device, it doesn’t mean they’re safe. You must have the device properly secured in your car, and you must have your child properly secured in the device.”

In Tennessee alone, as many as four out of five children are riding while improperly secured.

Understanding seat belt injuries and risks of back injury in kids

When an adult wears a seat belts, the lap portion goes across the bony part of the pelvis. “If we’re in a car wreck,” Louer explained, “it’s going to keep us from going forward and being thrown against the windshield or dash or thrown out of the car.”

But when a child who isn’t tall enough is wearing a seat belt rather than being secured in a car seat or booster seat, the force hits their abdomen during an accident. Such a force can result in a seat belt injury.

“It’s usually a pretty severe flexion injury of the spine,” Louer said. “You can also injure your abdominal organs — your bowel, kidneys, spleen, etc.” A recent Vanderbilt study found that more than half of patients who’ve had these severe injuries were unrestrained or improperly restrained.

Car seat and booster seat recommendations to prevent back injury in kids

The National Highway Traffic Safety Administration lists recommendations for car seat types and restraints based on your child’s development. The booster seat age range is 4 to 12.

After transitioning out of the rear-facing car seat, a child should ride in a forward-facing car seat until reaching the top height or weight given by the seat’s manufacturer. Then the child should ride in a booster in the back seat and remain in a booster until big enough for a seat belt only, when reaching at least 4 feet, nine inches tall.

A seat belt is appropriate when the lap belt stretches across the bony pelvis, not the abdomen. And the shoulder strap should reach across your child’s shoulder and chest rather than the neck or face. Even when transitioning to a seat belt, kids should ride in the back seat when possible until age 13.

The importance of keeping your child in a booster

Louer said that car and booster seat information can sometimes be confusing because there are so many types. A child’s development may add to the confusion. When children are between the ages of 4 to 8, the most common time for them to be in a booster seat, they may be sitting in a normal seat at the dinner table, giving the impression that they’re ready to use just a seatbelt in the car. But that is rarely the case.

“The problem is that until you’re closer to 5 feet tall,” he explained, “the safety belts don’t hit you in a place where they’re necessarily safe.” That’s why parents should follow car and booster seat recommendations to the letter to reduce the risk of back injury in kids.

Car and booster seat recommendations are based on years of safety studies. “We’re not trying to scare anyone,” Louer said. “But I think it’s important to know that it’s not just a friendly recommendation. It’s just heartbreaking when a child has a severe injury that could have been prevented with proper restraint and a little bit more care from their adults.”

Children staying active and playing jumprope in playground

Need help?

The Pediatric Orthopaedics program at Monroe Carell Jr. Children’s Hospital at Vanderbilt offers the region’s most advanced care in a family-friendly environment, treating a wide range of pediatric problems, including complex fractures; sports injuries; deformities of the spine, bones, hips or feet; scoliosis; and infections of the musculoskeletal system.

Learn More

Craig Louer, M.D., is an assistant professor in the Division of Pediatric Orthopaedics at Vanderbilt University Medical Center. He specializes in the treatment of children with spine deformities such as scoliosis as well as caring for children with neuromuscular diseases and lower extremity deformities. Dr. Louer currently sees patients at two clinics in Middle Tennessee – Vanderbilt Children’s Orthopaedics Nashville and Vanderbilt Children’s Orthopaedics Murfreesboro.