Major trauma is any injury that has the potential to cause prolonged disability or death. There are many causes of major trauma, blunt and penetrating, including falls, motor vehicle collisions, stabbing wounds, and gunshot wounds. Depending on the severity of injury, quickness of management, and transportation to an appropriate medical facility (called a trauma center) may be necessary to prevent loss of life or limb. The initial assessment is critical, and involves a physical evaluation and also may include the use of imaging tools to determine the types of injuries accurately and to formulate a course of treatment. In 2002, unintentional and intentional injuries were the fifth and seventh leading causes of deaths worldwide, accounting for 6.23% and 2.84% of all deaths. For research purposes the definition often is based on an injury severity score (ISS) of greater than 15. Classification Injuries generally are classified by either severity, the location of damage, or a combination of both. Trauma also may be classified by demographic group, such as age or gender. It also may be classified by the type of force applied to the body, such as blunt trauma or penetrating trauma. For research purposes injury may be classified using the Barell matrix, which is based on ICD-9-CM. The purpose of the matrix is for international standardization of the classification of trauma. Major trauma sometimes is classified by body area; injuries affecting 40% are polytrauma, 30% head injuries, 20% chest trauma, 10%, abdominal trauma, and 2%, extremity trauma. Various scales exist to provide a quantifiable metric to measure the severity of injuries. The value may be used for triaging a patient or for statistical analysis. Injury scales measure damage to anatomical parts, physiological values (blood pressure etc.), comorbidities, or a combination of those. The abbreviated injury scale and the Glasgow coma scale are used commonly to quantify injuries for the purpose of triaging and allow a system to monitor or "trend" a patient's condition in a clinical setting. The data also may be used in epidemiological investigations and for research purposes. Approximately 2% of those who have experienced significant trauma have a spinal cord injury. Causes Injuries may be caused by any combination of external forces that act physically against the body. The leading causes of traumatic death are blunt trauma, motor vehicle collisions, and falls, followed by penetrating trauma such as stab wounds or impaled objects. Subsets of blunt trauma