Lethal mechanisms in cases of inverted suspension from the lap component of seat belts

Causes of fatalities in motor vehicle occupants: an overview

Injuries from motor vehicle collisions are frequently encountered in routine forensic practice. While the most common lethal events involve blunt force trauma with injuries to the head and neck, chest, abdomen, pelvis and limbs, review of the literature and case files shows that a wide variety of other fatal situations can occur that may involve sharp force and penetrating trauma, incineration, drowning, asphyxia, organic diseases and combinations of these. The following overview details potential factors that may contribute to death following vehicle crashes.

Vertebral artery transection: an unusual lethal seat belt injury

An 89-year-old man involved in a vehicle crash was found at autopsy to have a linear seat belt mark on the right side of his neck associated with extensive injuries of the right paraspinal muscles with fracture-dislocation and separation of cervical vertebrae 5 and 6. There was also fracture of the right facet joint between cervical vertebrae 5 and 6 and laceration of the right vertebral artery. Death was due to a cervical seat belt injury with spinal fracture and laceration of the right vertebral artery. The presence of extensive injuries to the right paraspinal muscles and cervical vertebra 5-6 fact joint beneath the seat belt mark would be in keeping with trauma due to the belt webbing, rather than mere hyperextension/flexion of the cervical spine. This report demonstrates a rare form of seat belt injury, transection of the vertebral artery, and suggests that the finding of seat belt markings on the lateral aspect of the neck should prompt examination for this type of lethal vascular injury at autopsy.