Rear-facing provides a superb way to travel for infants and toddlers. Statistically, it reduces the risk of death by 71%. The current recommendation by the American Academy of Pediatrics is to rear-face all children to the minimum of age 2 years. Researchers have studied children’s vertebrae and concluded that they simply are not developed enough to withstand crash forces until around that age. There has been much heated debate over rear-facing, especially between parents who feel it is a parenting choice and that their children have especially strong necks for their age. However, a 12 month old has the bone strength of a 12 month old, unless there are health issues involved, and no amount of baby push-ups will change that. Rear-facing to age 2 is just like wearing a seat belt: we know it protects children in the least harmful way. Read on to find out why.
In an updated article published in Injury Prevention in November 2017, authors Timothy McMurry et al found that rear-facing children under age 2 have a lower rate of injury. The original study, published in Injury Prevention in December 2007, lead author Basem Y. Henary et al found that forward-facing children under the age of 2, especially those in side impacts, are 75% more likely to be injured. When the original study was examined by a statistician for a lawsuit against a carseat manufacturer, it was found to have statistical errors and a re-examination of the data shows that there simply is not a large enough sample of injured children to show whether or not rear- or forward-facing is safer after age 2 in the United States. What does this mean? Overall we are doing a good job of keeping our kids safe while they’re in traveling in cars because at such a young age, they’re not being injured. Yay, right? Well, we can always do a better job because injuries to young children can be particularly devastating and lifelong.
Given that parents want to do what is best for their children, and still maintain a level of practicality in their daily lives, what is best practice? When should a child be turned forward-facing?
Let’s get into how crashes work. Physics—Newton’s 1st Law—tells us that everything will keep moving toward the point of impact until it stops. At 53.5%, the most common type of crash is the frontal crash. In a frontal crash, the entire back of a rear-facing carseat absorbs crash forces as it moves forward and rotates down, protecting the child’s head, neck, and spine. The child will stay moving forward and slide up the carseat until he hits the harness and stops, then will slide back down as the carseat rebounds after the initial impact. This all happens in a split second.
Side impacts happen only 20.1% of the time, but because there is so little space between the passenger and the impact, the injuries can be severe. However, the rear-facing carseat protects the head, neck, and spine as it rotates down and the back of the carseat twists to the side. Since there is almost always an element of forward motion in a side impact—such as when a vehicle is going straight through an intersection when it is struck on the side by a red-light runner—a rear-facing seat does a better job of keeping a child’s head contained within the safety of the seat.
There are actually 3 collisions that occur in every crash regardless of the direction of the impact: the vehicle crash, the human crash, and the internal crash. The vehicle crash is pretty straightforward—it is where the vehicle hits another vehicle or object. At this point, the vehicle crushes and absorbs crash energy.
The human crash is where the body hits something in the vehicle. Moving at the same speed and direction as the vehicle, the body will encounter the seat belt (or harness), or the steering wheel, dashboard, or ground outside if unbuckled. If there are other unbuckled items in the vehicle, they are projectiles and may also hit passengers and become part of the human crash.
The internal crash is where the organs of the body slam against each other or bones, causing internal bruising, broken bones, and tissue tears. This is because the organs are traveling at the same speed as the vehicle until they come to a stop.
The Insurance Institute for Highway Safety (IIHS; the same place that rates vehicle safety) has several excellent videos showing how the body reacts in a crash. The full video can be found here, but it is over 20 minutes long.
To calculate crash forces, a simple equation we use a simplified equation: Weight x Speed = Restraining Force. So, if a child weighs 10 lbs. and the car is going 30 mph, the force required to hold that child is 300 lbs. For an older, heavier child who is 30 lbs. in a car going 30 mph, the force required is 900 lbs.
What about rear-facing kids who are in a rear impact? Isn’t that just like a forward-facing child in a frontal crash?
No. A forward-facing child in a frontal impact is held back only by the harness—his head is flung forward. A top tether is vitally important for this reason since it keeps the top of the carseat from tipping forward and allowing the child’s head to come out even more.
A rear-facing child in a rear impact moves with the carseat. Just like a rear-facing carseat in a frontal crash that supports the child’s head, neck, and spine, it does the same in a rear impact as it cradles the child toward the point of impact.
Rear impacts account for only 25.4% of crashes. The vast majority of rear impacts also happen at lower speeds or at speeds where the striking vehicle is slowing, with 1.3% occurring at more than 26 mph.
“More on Rear-Facing Research.” SBS News, January 2018.
What about an older rear-facing child’s legs—won’t they be broken by the back seat?
Maybe, but it is unlikely. Again, statistically, the most common type of crash is the frontal crash. Remember that physics lesson that taught us that everything moves toward the point of impact, including the child’s legs which will fly up. Broken legs are much easier to treat than a broken neck, which is a real risk if a child is turned forward before the neck bones have hardened and the ligaments have developed enough to withstand crash forces. Another study tells us that the legs are more likely to receive serious injuries in crashes when a child is forward-facing, most likely from the child’s legs crushing into the front seat backs.
What is your child’s anatomy and what makes them so fragile?
If you are here reading about rear-facing, you have probably heard about your child’s fragile neck and the importance of rear-facing to protect it. When babies are born, their spinal columns are not completely fused (ossified is a popular term online), just as the rest of their bones are not completely developed. This allows for growth and flexibility (it would be very difficult to be born and grow if our skeletons were completely formed). Because the spinal column is not fused, it is held together with ligaments and cartilage, which can stretch. In a crash where the child’s head pulls away from the body, the ligaments and cartilage stretch, allowing the spinal cord to stretch. The spinal cord will stretch up to 2″, but it can only stretch ¼” before sustaining permanent damage.
For more information and links to articles, please see CarseatBlog’s article, Why Rear-Facing Is Better.
The professional association that most pediatricians belong to, the American Academy of Pediatrics, has recommended since 2002 that children remain rear-facing to the limits of their convertible carseats for safest protection in vehicles. Unfortunately, because many pediatricians are busy with day-to-day appointments and running their businesses, child passenger safety rests on the back burner and they are unaware of the recommended guidelines of their own association. If this is the case with your pediatrician, please print the guidelines and take a copy to his/her office. The guidelines changed in March 2011, so word-of-mouth is very important to let our health providers know about the changes. At the same time, the National Highway Traffic Safety Administration (NHTSA), changed its guidelines to reflect a longer rear-facing and harnessing timeline. NHTSA’s guidelines state that a child should remain rear-facing for as long as possible, until the child reaches the top weight and height limit of the rear-facing carseat.
Which carseat is best for rear-facing?
Many parents start out with an infant seat/rear-facing only seat when they have a newborn and that’s fine. Generally this will not be the carseat from which the child transitions to a forward-facing only carseat since most children outgrow their infant seats, even the larger ones, before age 2; therefore, it is best to transition from infant seat to rear-facing convertible seat. Convertible carseats can be used rear-facing for much longer than infant seats because they are taller and have higher rear-facing weight limits. They can be turned forward-facing after the child reaches the rear-facing weight and/or height limits or minimum forward-facing limits.
Convertible carseats can also be used from 4 lbs. or 5 lbs., depending on the carseat. Each manufacturer rates their convertibles based on inserts and newborn fit, so it is important to read the instruction manual and labels. Verify weight limits in instruction manuals, which may be found on manufacturer websites, before purchase. Sometimes retailers will list incorrect weight limits on promotional information for carseats.
How do you know a carseat is a convertible carseat that can be used rear-facing? Some forward-facing only carseats look a lot like convertibles and it can be confusing. Convertibles have the distinguishing characteristic of 2 belt paths for installation: the rear-facing belt path is under the child’s thighs while the forward-facing belt path is behind the child’s back. Labels near the belt paths will help identify them.
Is there an upper age or weight limit for rear-facing?
The data does not show any danger to rear-facing past age 2 and indeed, there are practical advantages to doing so. It is easier to set your child in a rear-facing seat because they cannot slide out, it is easier for them to sleep, they cannot see what you are eating, and they cannot offer driving advice. As long as your child fits safely within the carseat, they can continue to stay rear-facing. Rear-facing past age 2 is called “Extended Rear-Facing.”
All carseats have upper weight and height limits for rear-facing. Check the carseat manual and labels on the side of the seat for the weight limits. Most have a height requirement of at least 1″ of carseat above the child’s head.
Note: there is required wording on every convertible carseat label that says, “Use only in a rear-facing position when using restraint with an infant weighing less than 2_ pounds.” It does not mean that the convertible only rear-faces to 20 or 22 lbs. What it does mean is that all children weighing less than the weight specified must ride rear-facing in that restraint. It is meant to keep caregivers from turning small children forward-facing too early.