In medical terminology, blunt trauma, blunt injury, non-penetrating trauma or blunt force trauma refers to a type of physical trauma caused to a body part, either by impact, injury or physical attack; the latter usually being referred to as blunt force trauma. The term itself is used to refer to the precursory trauma, from which there is further development of more specific types of trauma, such as concussions, abrasions, lacerations, and/or bone fracturing. Blunt trauma is contrasted with penetrating trauma, in which an object such as a bullet enters the body.