Impact injury to a body within or upon a rapidly moving object caused by the forces exerted when the object comes to a complete stop. The majority of deceleration experiments have been conducted in connection with air travel, where the acceleration factor is typically much greater than in land vehicles.When the brain collides with the layers of the skull, it causes deceleration trauma. As a result, the victim's motor skills and speech may be harmed. Concussion, contusion, coup-contrecoup, diffuse-axonal injury, and penetration are all examples of trauma.