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Car seats save lives, just as seat belts do. However, many parents tend to be frustrated by child seats, because they can be difficult to use.

As if to bear that out, SafeKids worldwide estimates that three quarters of child safety seats are improperly installed. That generally means they're installed too loosely, which allows the seat – and the child in it – to fly forward in a crash. It can also mean the seat is not angled correctly. Another common misuse of car seats is not strapping the child into the seat tightly enough. A loose harness can’t hold a kid in a car seat during an accident, which may cause the child to fly out of the seat.

Kids need correctly installed car seats because their bodies are different from adults'. The National Highway Traffic Safety Administration (NHTSA) recommends children be in car seats or booster seats until the age of 12, or when they are at least 4-feet-9-inches tall, which is the height at which someone can safety use a seat belt.

Seat Belts vs. Car Seats

Seat belts are designed to fit adults. They dissipate the energy in a crash so it doesn’t hit passengers' bodies all at once. Even at low speeds, crash forces in an accident can approach more than 30 Gs. For comparison, fighter pilots are able to sustain up to 9 G’s at a time, and that’s with the help of special suits designed to keep their blood flowing. Seat belts grip the body by its strongest points – the hips, shoulders, and rib cage.

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Seat belts do a phenomenal job keeping adults restrained in a crash. They aren’t as good at protecting kids, however. Put a five-year-old in an adult seat belt and it's easy to see that it doesn't fit right. The shoulder belt is likely to pass over the child's chin. When sitting upright in the seat, they are not able to bend their knees to reach the floor. If they slouch enough to bend their knees, the lap belt is likely to cross their stomach. In a crash, a seat belt crossing a child's abdomen or neck can do serious damage to a child’s vital organs. The child could also slide underneath the belts. That’s why it’s so important that children ride in the correct child safety seat for their age and size.

Types of Child Safety Seats

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Babies under two years old still have a soft bone structure that can't withstand the forces of a car accident. In particular, their necks aren't strong enough to hold the weight of their heads as they get propelled forward in a crash. The only way to keep babies safe in the face of a 30-G crash is to have them sit a rear-facing car seat. This allows the child seat to absorb the crash energy and spread it proportionally along their body. Rear-facing car seats come in two forms: a rear-facing-only type, often called an infant car seat, and a convertible car seat that can be installed as either a rear-facing or forward-facing seat, allowing it to grow with the child.

Doctors recommend that kids remain facing rearward until they are at least two years old or until they reach the maximum height and weight for a rear-facing car seat. Forward-facing car seats use a five-point harness and side bolsters to keep kids safe. The five-point harness holds the child's hips, shoulders, and pelvis in place. Children between the ages of two and five are still more flexible than adults and could slip out of a three-point seat belt during a crash. Forward-facing car seats with five-point harnesses keep them restrained. Side bolsters in a forward-facing seat help absorb crash energy as well. In fact, the design of many forward-facing child seats is based on the seats and harnesses used by race car drivers.

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When a child outgrows a forward-facing car seat with a five-point harness, they still aren’t ready to use a seat belt alone. A booster seat raises the child to a height that allows the car’s seat belt to work properly. Meant for children between 8 and 12 years old, booster seats are designed to lift kids into place so the belt properly crosses the strong points of their bodies. The seat belt on a child in a booster seat needs to be across their shoulders and lap. Just having the belt across the lap would allow the child to slip either up or down out of the booster seat in a crash.

Keep in mind that there are multiple types of booster seats. Some are just a seat that raises the child higher in the car, while others have side bolsters and head restraints. Side bolsters provide extra protection in side crashes, where all car occupants are especially vulnerable.

Child Seat Installation

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Having your child properly buckled into the correct child seat for their age and size, however, is only half the battle for parents. The car seat has to be properly secured to the car, either using the car's seat belt or dedicated LATCH anchors and tether straps. LATCH anchors, also known as the “Lower Anchors and Tethers for Children Restraint System,” are usually found in between the cushions of the seats, as well as above them. Check your owner’s manual to find out where your LATCH anchors are.

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A 2011 nationwide study done by the NHTSA found that 46 percent of child seats are installed incorrectly. They also found that 20 percent of all drivers don’t read the instructions on how to install their child seats, even though 90 percent feel they know how to install them correctly. The most frequent mistake cited by child-seat installation techs is that the seats aren't buckled in tightly enough. Front- and rear-facing child seats should have no more than 1 inch of play at the top when properly installed. If they're installed using the car's seat belts, the belt retractors need to be locked, either with the car's automatic seat-belt locking retractors, or with clips. They also need to be angled correctly so that a child's head doesn't lean too far forward and they're not so reclined that they'll slide out from under the belts in an accident. Installers and child-seat testers recommend a 30 to 45 degree angle for the child seat. Within that range, younger kids should recline more; older kids less.

The National Highway Traffic Safety Administration estimates that proper use of child seats could reduce infant deaths in car crashes by 71 percent, and deaths of children between the ages of one and four by 54 percent. Yet 31 percent of young kids killed in car crashes had no child seat at all.

It's not enough for adults to buckle up. We need to do more to protect our kids.

To determine what type of car seat your child needs, visit: www.nhtsa.gov, and check out www.safekids.org to find a child-seat installation clinic near you, where certified experts will check to ensure your child is properly restrained in their car seat.