Infants to 4 years old
Children's necks are still growing and are weak. Add to this a head that, relative to the size of the body, is proportionately much bigger than that of an adult, and you can understand why a baby or toddler seat needs to face the rear of the car. This ensures that in the event of a crash, the forces are spread over the back and head, which reduces the load on the neck in frontal impacts. It is beyond doubt the safest way for a baby to travel. If your toddler doesn't like facing the rear, place a mirror in such a way that she can see you and you can check on her at a glance.

Children 4-10 years old
Children's necks are stronger and they are now able to face the front. Their hip bones, however, are still underformed – the iliac crest that exists in adults is not yet fully developed. It is this part of the hip bone that prevents an adult's lower body from slipping forward under the seatbelt in the event of a collision.

A booster cushion guides the lap belt across the pelvis, as low as possible towards the thighs and not over the soft belly. The torso belt runs diagonally across the chest. It does not affect the child's safety if the torso belt rests on the child's neck, but if the safety belt is tucked under the arm or behind the back, the child is not as protected in an accident. Booster cushions come in different models and sizes, with or without a back rest. Some cars can be equipped with an integrated booster cushion.

Information courtesy of Volvo.