Why children are vulnerable in a car, and how we can ensure their safety: Advice from Volvo
Why children are vulnerable in a car, and how we can ensure their safety: Advice from Volvo
VULNERABLE PASSENGERS
Babies and children are especially fragile passengers. Relative to the rest of their bodies, their heads are large and heavy. The head of a nine month old baby, for instance, makes up a quarter of its total weight. By way of comparison, the head of an adult male is only six per cent of his total body weight. A baby’s head has different proportions too. Its face is relatively small compared with the rest of its head and brain. If a baby or child suffers head injuries, this often means brain damage, which is usually much more serious than facial injuries. Head injuries in babies are frequently more severe because their skulls are thinner than an adult’s, providing less protection for the brain.
The neck vertebrae of a new born baby are composed of separate portions of bone joined by cartilage. In other words, the baby’s skeleton is still soft. This cartilage turns into bone over the first three years of the baby’s life. The process of cartilage hardening into bone continues right up until puberty. There is similarly gradual development of the muscles and ligaments in the neck. Human neck vertebrae also change shape progressively throughout the years when a person is growing, from the horizontal vertebrae of the small child to the saddle-shaped ones of the adult. Being saddle-shaped also means that the vertebrae will interlock and support one another if the head is thrown forward. The young child lacks this extra protection. Another factor which makes a child more vulnerable is the fact that its pelvis is still relatively undeveloped. Apart from overall size, one key difference between the pelvis of a child and that of an adult is that the distinctive hip bone structure called the iliac crest is not fully developed in the child. The size and shape of the wearer’s hips have a direct bearing on the way that the safety belt will stay in place. The shape of the iliac crest in adult hips helps keep the lap belt low down in the event of a crash, preventing it from riding up and possibly damaging the internal organs. The human pelvis remains relatively rounded in shape until the child reaches the age of about ten. The iliac crest does not develop its more angular adult shape until puberty.
The safest way of traveling in a car is backwards. It would actually be better for all of us to sit facing the rear of the car, but given the existing designs of our cars, this is not feasible for adults. Young children, however, can and should travel facing the back of the car for as long as possible. In a frontal collision, the head of a forward-facing car occupant is thrown forward with considerable force. Its momentum propels it downwards onto the breastbone and then back up again. An adult neck can withstand this strain relatively well, but a small child’s neck cannot. Given that frontal collisions are the most common type of crash and often the most serious type too, it is particularly important for the youngest children to sit in rearward-facing eats.
TIME TO LOOK FORWARD
Sooner or later the child grows out of its rearward-facing child seat. This is generally at the age of three or four. Now it’s time for him or her to travel facing forwards, seated on a booster cushion with or without a special backrest section. Make sure that the booster cushion has ‘horns’ or similar projections designed to keep the lap belt low down in front of the hips and across the tops of the thighs. These projections are also there to keep the booster cushion in place if there is an accident. Some cars, including a number of Volvo models, have their own integrated forward-facing booster cushions – a very useful form of child restraint.
In cars without head restraints, a booster cushion with a backrest or a forward-facing child seat will provide support for the child’s head in the event of a rear-end collision. Child restraints of these types also generally make the legs of smaller children more comfortable, and any side projections built into the top of the backrest section will give the child’s head lateral support. These projections also help the child to sit better and more securely, and less likely to fall asleep with its head dangling to one side.
Having a backrest section for the booster cushion also helps the belt to stay in place better by the neck and over the shoulder. When a child, sitting on a booster cushion with or without a backrest section, is buckled in using a three pint safety belt, it is important for the belt to be positioned correctly. The main reason for using a booster cushion is not to help the child to see more, but rather to achieve the right belt geometry. The less slack there is, the better the belt will protect your child.
The booster cushion is there to raise the child up higher, to bring the belt into a better position across the hips and thighs. The lap section of the belt must always be worn as low down as possible, and not across the stomach. The diagonal section of the belt should sit firmly across the shoulder and chest. Remove any slack after you have fastened the child’s safety belt. It doesn’t matter if the belt is partly on the child’s neck. It may not look very comfortable, but it certainly won’t strangle the child if there is an accident. If the car were to stop abruptly, the child’s head would move forward and the belt would move further out onto the shoulder. The risk is much greater if the diagonal belt is worn too far out on the shoulder. This could allow it to slip further down the arm in the event of an accident, when the child’s head would be thrown forward. With the belt then too far down the arm, the child would not be restrained as well as it should.
Under no circumstances should the child travel with the diagonal belt under both arms. In a crash, the child would be thrown further forward, with the risk of hitting some part of the car interior. There would be much greater risk of chest or stomach injuries because the human skeleton is weaker, lower down the Thorax. Never use an ordinary cushion or telephone directory instead of a proper booster cushion. An ordinary cushion would be too soft and it would not be properly anchored as a booster cushion is. In an accident, a cushion would simply be flattened, while a telephone directory would slide forward. Using either of these could cause the child to slip forward, out under the lap belt.
WHAT IS REQUIRED BY LAW?
The regulations governing which seats children of various ages may use in cars vary from country to country, as do the prescribed types of child restraint. Children traveling in cars should always use an appropriate type of child restraint, properly fastened.
DANGER TO OTHER OCCUPANTS
If the child is unrestrained in the back seat, he or she risks serious injury or even death if the car collides head-on. And anyone in the seat in front risks having this great weight unleashed on them from within the car, with equally serious consequences, or the child could even go straight through the windscreen and hit the same object that stopped the car dead in its tracks. Bear in mind a few comparisons:
Traveling unrestrained and then crashing at just 15km/h is rather like climbing up onto a dining chair and letting yourself fall headlong on to the floor.
But if the car is going at 20km/h the severity of the crash is more like arranging four dining chairs one on top of the other before you let yourselves fall.
To visualise a crash at 30km/h, imagine arranging eight chairs, one on top of another, before you take the plunge.
So please use those safety belts and child restrains ALWAYS.
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