Who should sit rear-facing?

All children who still fit in their rear-facing convertible car seat’s rear-facing height and weight limits should sit rear-facing. Many states require rear-facing until at least 24 months old. Find out LOTS MORE about rear-facing past age 2 here.

What do experts recommend? The American Academy of Pediatrics recommends kids “should continue to ride rear-facing in a convertible car seat for as long as possible,” which means till they are too tall or too heavy for their child safety seat. Likewise, NHTSA recommends “Your child should remain in a rear-facing car seat until he or she reaches the top height or weight limit allowed by your car seat’s manufacturer.”

Why is rear-facing safer?

In a crash everyone moves towards the point of impact, so in a frontal crash everyone moves toward the front of the car. If you’re forward-facing in a car-seat or a seat belt, your upper body stops quickly because the chest strap on the car seat or the seat belt holds you back. However, your head doesn’t stop as quickly! Instead, it moves all the way forward until your chin touches your chest, and then goes all the way back. It whips forward and back in the blink of an eye. This is called whiplash.

Since an adult’s head is just 6% of their body weight, you can withstand having your head pulled violently away from your body. You’ll be sore for a few days, but you hopefully won’t have any lasting injury.

It’s quite different for a newborn, whose head is a whopping 25% of its body. This means that if a newborn were forward-facing in a frontal crash, their head would pull forward with four times as much force as would an adult’s! 

Strength and rigidity of the bones in the spine also contribute to how well you can tolerate your head being pulled forward and back in a crash. The bones of an infant’s spine are made up of soft, stretchy cartilage. The ligaments that connect these cartilaginous bones are also underdeveloped and stretchy. Scientists have found that a newborn’s spinal column (bones + ligaments) can stretch up to 2 inches, whereas the spinal cord inside can stretch only 1/4 of an inch. If the spinal cord is forced to stretch more than it can, it breaks, leaving the baby paralyzed or worse.

Children are not just smaller adults; their bodies are differently proportioned and structured, and this difference affects their ability to tolerate the whiplash motion.

Physics: How Rear-Facing Works in a Crash

In a frontal crash, when everyone moves to the point of impact–the front of the car–a rear-facing baby will move in a different way. A rear-facing baby will move into the back of his car seat and will slide gently up the car seat. This allows the back of the car seat to absorb the brunt of the impact and distribute the remaining forces along the child’s entire back, which is the strongest part of his body. The most important part: because he sits rear-facing, the child’s head, neck, and torso all move together in a straight line. The whiplash motion is avoided totally.

Rear-facing seats also protect children better during side-impact crashes (the most deadly types of crashes). In a side-impact, everyone moves toward the impact. A forward-facing adult or child will pivot around their pelvis and turn to the side, leaving their head at risk for hitting the doorframe, window, other hard structures, etc. When a child is rear-facing in a car seat, the car seat itself does the pivoting, allowing the child’s body to stay in a straight line. And since his head usually does not extend beyond the sides of the car seat, his head is better protected.

See it yourself!

Watch this crash test of two properly installed car seats (one rear-facing and the other forward-facing) in a frontal crash. Both dummies are properly secured with snug harnesses in the car seats. Watch how the rear-facing dummy’s head and back are cradled by the back of the car seat, while the forward-facing dummy’s head and neck are thrown forward in the whiplash motion. (video courtesy of the University of Michigan)

Crash Simulation: Why rear-facing is safer

At a trade show, The Car Seat Lady used a crash simulator. She wore a heavy helmet to mimic the size and weight of a child’s head to really get a full body experience. Watch to see what happens and how she tolerates the different positions, and listen to her excellent description of why rear-facing is safer.