Results of new research in the United States suggest a child in a booster seat has less than half the risk of injury of a child wearing only an adult seat belt.

The study, published on Wednesday in the Journal of the American Medical Association, looked at more than 3,600 crashes involving children who were too big for child car seats but too short for adult seat belts. In accidents, their injuries includes abdominal and spinal cord damage from being bent forward over the lap belt as well as injuries to the face and brain from the head hitting the knees.

Wearing an adult seat belt cut a child's risk of injury by 38 per cent, but using a booster seat with a belt cut it by 78 per cent, said the study's lead author, Dr. Dennis R. Durbin of the Children's Hospital in Philadelphia.