In this study the case of a collar--bone wedge--fracture caused by the impact of safety--belt clasp was described. The presence of wedge--fracture is proof of an active mechanism of injury. This kind of fracture was described in traffic accidents as a Messerer fracture so far. The case of a wedge--fracture of the ulnar caused by impact of a baseball bat was also described. This study proves that Messerer fractures of bones are not characteristic only for long bones but may be connected with other types of bones if only the power of impact is strong enough to cause excessive bending of the bone trunk.