A car seat harness consists of the straps that fit over the child to help protect him or her in the event of an accident. A five-point harness, which fits over the child’s shoulders and hips, is the preferred type of car seat harness for most infants and toddlers. Most U.S. states require children less than a certain age and weight to ride in car seats or booster seats, and car seat manufacturers specify a weight range that is safe for use. The harness should always fit the child snugly for maximum protection. Also, the fastener between the shoulder straps should be at the proper height over the child’s chest, not too high or low.
For infants and toddlers up to a certain weight and age, the five-point harness is usually recommended for maximum safety. It consists of two shoulder straps that clip together over the child’s chest and connect to two additional straps that fit over the hips, along with a fifth strap through the legs. It is important to adjust the straps of a five-point harness properly, with the top clip over the chest rather than near the neck or belly. If the chest clip is positioned incorrectly, it can injure the child in an accident. Many car seat shoulder straps are also height adjustable and should be positioned just over the child’s shoulders, not too low or too high.
Most infants and toddlers should be in five-point car seat harnesses until they reach approximately 40 pounds (about 18 kg), although this guideline can vary depending on local laws. Car seat manufacturers also specify a weight range for each individual product that is appropriate and safe for use. Older children may ride in a booster seat, which uses the car’s existing safety belts but positions the child high enough to use them properly. An older child should use a booster seat until he or she is tall enough for the vehicle’s safety belt to fit securely over his or her shoulder, as it does for an adult. If the strap does not fit properly, it will not provide adequate protection in the event of a crash.
Some local fire departments, police stations, and emergency medical providers offer free checks to make sure that the car seat harness is adjusted properly for the child. They can also adjust the connections to the vehicle’s restraint system to ensure a snug and secure fit. The American Academy of Pediatrics also provides more detailed information on age, weight, and height requirements for different types of car seat harnesses.