Try catching the harness strap at the child's shoulders. To test if your child safety seat is installed tight enough in your vehicle, Hall recommends grasping the safety seat at the location where the seat belt loops through it and then attempting to pull it forward and side to side. One of the most important things that parents can do is to read and follow the manufacturer's instructions and then seek assistance if the instructions are too confusing or if there is a reason that it just doesn't seem to work quite right. But the recommended practice for buckling up infants endorsed by the American Academy of Pediatrics and promoted by our Center advocates taking more safety precautions. We recommend that infants ride in a rear-facing position until they weigh at least 20 pounds and are at least a year old.
Infants take about a year for the bones of the neck to fully develop regardless of their size.
Kids should stay in harness-type restraints until they have outgrown them, Hall said. This usually occurs when they reach about 40 pounds. Belt-positioning booster seats are designed to raise the child up to a proper fit of the adult lap and shoulder belt, and can be used until an adult seat belt can fit properly. Frequently parents move their child into an adult seat belt before they are ready, Hall said. It really is situational.