Anatomy of a car crash - Give kids a boost

Children have a differently shaped pelvis, and are much smaller than adults, which mean they can easily slide out from under an adult belt. The law says children must use a booster cushion until they are at least 135cm tall, or 12 years old, to help protect their internal organ and their spines.

Lena Franzen, a Swedish paediatrician says: 'Children's injuries are likely to be multi-organ and abdominal if a belt is not fitted correctly, and they also risk breaking their back and suffering injury to the spinal cord.'

They might be tempted to put their arm over the shoulder belt, but as the video shows, this makes the belt ineffective and dangerous.

• Volvo crash test footage on Windows Media
• Volvo crash test footage on on Real Player