What type of injury does a seat belt commonly cause in terms of chance fractures?

A seat belt commonly causes flexion injuries, particularly in the context of the torso during a collision. When a person is restrained by a seat belt, the force of impact can cause the upper body to flex forward, while the belt holds the lower body in place. This flexion motion can lead to injuries such as chance fractures, which are typically characterized by horizontal fractures through the vertebral body and involve a flexion-distraction mechanism. The resultant injury pattern is associated with significant forward bending of the spine as the pelvis remains stable, creating shear forces that result in these specific types of fractures.

Understanding this mechanism is crucial for recognizing the patterns of injury that can arise from using seat belts, emphasizing the importance of proper restraint use in vehicles to reduce the risk of such injuries.