Blunt Injuries, Signs Of

The signs of blunt injuries (also called blunt trauma or blunt force trauma injuries) include lesions such as abrasions (scrapes), contusions (bruises), and lacerations (cuts), but can also include bone fractures and organ ruptures. Blunt injury lesions occur when the skin of the human body makes contact with a blunted object in the form of a crushing impact or penetrating blow. For the investigations performed by forensic scientists, lesions are usually found to result from assaults and beatings of a victim often in the form of hitting, kicking, punching, or clubbing; but they can also occur from accidents such as falls. The general form of such lesions usually assumes the pattern or characteristic of the impacting blunt object. For the most part, blunt injuries to the human body cause pain and discomfort. If severe enough, however, blunt injuries sustained to the head can cause death primarily due to blood clots in the lungs that cause blockage of the major pulmonary arteries or foreign objects that flow to the brain.

Abrasions normally include only external injuries. These injuries result when the skin is rubbed away by contact with a blunt object (such as a block of wood) or rough surface (such as being dragged across a concrete floor). The signs of abrasions usually appear as lines of scraped skin with small areas of bleeding.

Contusions usually include either external or internal injuries. These injuries are the result of powerful trauma that injures an internal bodily structure (such as the rib cage) without actually breaking the skin. Contusions can be caused by blows to the abdomen, chest, or head with a blunt object such as a fist. The signs of contusions appear as a bruise beneath the skin or may not appear at all, only showing up through the use of imaging examinations. The injury occurs when the small blood vessels located beneath the skin are damaged. As a result, the unbroken skin surrounding the fragmented blood vessels swells and turns dark shades of blue, red, and purple as blood runs into neighboring tissues. The amount and degree of such discolorations can vary by the victim's weight, where obese people show color more than lean people. Initially, victims may feel weakness and pain, and show signs of perspiration. Signs of brain contusions are less noticeable and, thus, more difficult to analyze. The severity of brain trauma is usually more obvious on the opposite side of impact because, upon contact with a blunt object, the brain will slide to the opposite side of the skull .

Lacerations (or open wounds), such as tears, generally include either external or internal injuries. The injury results in an irregular break or opening in the skin, sometimes called a separating wound. The edges of the wound may be dirty, jagged, or bleeding. These injuries are caused by a large force against the body. Lacerations usually affect only the skin, but may damage deeper tissues of the body such as bones, fat, muscles, and tendons.

see also Pattern evidence; Puncture wound.