Changing trends with abdominal injury in seatbelt wearers.

Seatbelts were incorporated as standard equipment for automobiles constructed in North America in 1964. The first seatbelt law was made mandatory in Canada as of 1 January 1971. Between January 1976 and January 1980 38 patients involved in automobile accidents while wearing passive restraints were treated at l'Hôpital du Sacré-Coeur: 32 of these 38 patients had signs and symptoms of abdominal injury. These patients wearing passive restraints had an unusually high incidence of gastrointestinal injury in comparison to previously reported patients not wearing restraints. Twenty-seven of the 32 patients had injury to the bowel or the bowel mesentery. This different spectrum of injuries is most likely related to the altered physics of rapid deceleration caused by restraint with the lap belt and shoulder harness.