The main purpose of a child restraint sytem is protect the child in the event of an accident. Given that the seat belt is specifically designed for an adult, children need to be boosted or elevated in the seat (this is where we get the name booster or elevator from) in order to be properly protected.
As the child grows the child restraint must be able to accommodate them until they begin to use the seat belt. In this case booster seats are designed to allow the seat belt to adapt correctly to the child and adequately secure the child.
Children between approximately 4 and 12 years of age (depending on their weight and height) can begin to use child car seats for Groups 2 and 3 (R-44/04) or child restraint systems for children over 100cm tall (R-129). In both cases the seat belt places a key role and starts to become used in order to then subsequently only use the seat belt without needing a child car seat (the minimum height is 135cm).
We can currently find the following child restraint systems on sale which use a seat belt to secure them:
It is important to bear in mind that the seat belt should thread through the belt slots or guides indicated by the manufacturer. This is how we can avoid incorrectly securing the seat.
In addition to offering better protection, a booster seat with a backrest has more markings showing how to position the belt correctly.
The belt should never go over the child's neck and it should be adjusted to fit as far down as possible over the hips. We should of course ensure that it is not loose-fitting.
This is how a seat belt should be positioned, both with or without using a child car seat: