Rear-Facing vs. Forward-Facing
by Kathleen Weber, Director*,
Child Passenger Protection Research Program,
University of Michigan Medical School
Safety experts and the American Academy of Pediatrics recommend that children remain rear-facing as long as possible and never travel forward-facing before they are 1 year old and also weigh at least 20 pounds to reduce the risk of serious neck injury and lifelong disability. All new convertible seats available today allow a child to remain rear-facing until they weigh up to 30 or 35 lb, depending on the model.
When the child is rear-facing, the head, neck, and thorax are restrained together by the back of the CR in a frontal crash. There is little or no relative motion between the head and torso that could load the neck. If the same child were facing forward, the harness would restrain the torso, but the head and neck would pull and rotate forward, leading to the potential for serious upper spinal injury.
There are many misunderstandings and misconceptions about rear-facing vs. forward-facing that lead even the best intentioned parent or pediatrician to believe a child is "safe" facing forward when he is still very young. These come from obsolete ideas and advice that may still appear in older pamphlets and pediatric literature and are not the current recommendations of the American Academy of Pediatrics.
Real-world experience has also shown that a young child's skull can be literally ripped from her spine by the force of a crash. The body is being held in place, but the head is not. When a child is facing rearward, the head is cradled and moves in unison with the body, so that there is little or no relative motion that might pull on the connecting neck.
The most common misunderstanding is that a child is ready to travel facing forward when his neck muscles are strong enough to support and control his head. However, when a car hits something at 25 to 30 mph, it will come to a stop at a negative acceleration rate of from 20 to 30 G. Because of the time lag between when the vehicle stops and an occupant stops, and the fact that the head of a forward-facing adult or child is still free to move relative to the restrained torso, the head may experience as much as 60 or 70 Gs acceleration for a brief moment. Even the strong neck muscles of military volunteers cannot counteract such forces. Instead, the rigidity of the bones in the neck and strength of the connecting ligaments (not the muscles) hold the adult spine together and keep the spinal cord intact within the confines of the vertebral column.
Very young children, however, have immature vertebrae that are still partly made of cartilage. These are soft and will deform and/or separate under tension, leaving just the spinal cord as the last link between the head and the torso. According to documented research, autopsy specimens of infant spines and ligaments allow for spinal column elongation of up to two inches, but the spinal cord ruptures if stretched more than 1/4 inch. Real-world experience has shown that a young child's skull can be literally ripped from her spine by the force of a crash.
Another aspect of the facing-direction issue that is often overlooked is the additional benefit a child gains in a side impact. Crash testing and field experience have both shown that the head of a child facing rearward is captured by the child restraint shell in side and frontal-oblique crashes, while that of a forward-facing child may be thrown forward, around, and outside the confines of the side wings. Field data show better outcomes for rear-facing children than forward-facing children, even though most CRs are not specifically designed to protect children in side impact.
Some older convertible CRs indicated in their instructions that a child should face forward when her feet touch the vehicle seatback or when the legs must be bent due to lack of space. This prohibition is not justified by any crash experience or any laboratory evidence, and these instructions have now been revised. There have not been any crashes documented in which rear-facing children sustained leg injuries because they were rear-facing. Even if this were the case, broken legs are easier to fix than broken necks. The only physical limit on rear-facing use is when the child's head approaches the top of the restraint shell. At this point, she should be moved to a rear-facing convertible restraint, or, if the child is already using one and is over one year, to its forward-facing configuration.
There are no magical or visible signals to tell parents, pediatricians, or technicians when the risk of facing forward in a crash is sufficiently low to turn the child around. In an international research and crash review conducted several years ago, the data seemed to show a change in outcome at about 12 months between severe consequences and more moderate consequences for the rare events of injury to young children facing forward in a CR. At the time, one year old was useful as a simple benchmark, but now the message is to keep the child facing rearward as long as possible within the weight and height limits of the CR. This may be as long as 18 to 24 months.
Parents and pediatricians need to know what the real reasons for extending the rear-facing period, in order to be able to make an informed judgment.
Reprinted with permission from the author.
SafetyBeltSafe USA version
Other works by author: Crash Protection for Child Passengers (Adobe Acrobat file)
How Long Should Children Ride Facing the Back of the Car?
According to a 2008 article in the professional journal Pediatrics, children under age two are 75% less likely to be killed or suffer severe injuries in a crash if they are riding rearfacing rather than forward facing. In fact, for children 1–2 years of age, facing the rear is five times safer.
If a baby is riding in an infant–only seat (the type that usually has a handle and detachable base) it should be replaced with a rear–facing convertible seat before the baby reaches the maximum weight specified (22-35 pounds) or if the top of the head is within an inch of the top edge of the seat. Most babies outgrow the typical infant–only seat before they are one year old, but they are not ready for a forward–facing seat. New convertible seats available today allow children to remain rear facing until they weigh 30-45 pounds, depending on the model.
Babies have heavy heads and fragile necks. In a crash, an infant’s soft spinal column can stretch, leading to spinal cord damage if he is riding facing forward. The baby could die or be paralyzed permanently. This is true even for babies who have strong neck muscles and good head control. The neck bones are flexible, and the ligaments are loose to allow for growth.
If the baby is facing forward in a frontal crash, which is the most common and most severe type, the body is held back by the straps — but the head is not. The head is thrust forward, stretching the neck and the easily injured spinal cord. Older children in forward–facing safety seats or safety belts may end up with temporary neck injuries or fractures that will heal. But a baby’s neck bones actually separate during a crash, which can allow the spinal cord to be ripped apart. Picture what happens if someone yanks an electrical plug out of a socket by the cord, causing the wires to break.
In contrast, when a child rides facing rearward, the whole body — head, neck, and torso — is cradled by the back of the safety seat in a frontal crash. Riding in a rear–facing safety seat also protects the child better in other types of crashes, particularly side impacts, which are extremely dangerous, if not quite so common.
Children in Sweden ride rear facing until they are three to five years old, lowering traffic death and injury rates substantially. Although most safety seats sold in the U.S. are not designed to be used rear facing as long as those in Sweden, safety experts recommend that children ride rear facing as long as possible, at least until they are two years old.