Trauma (bodily injury) is a major social and medical problem in both developed and developing countries. Injuries are among the leading cause of death and disability in the world, and affect all populations, regardless of age, sex, income, or geographic region. In 1998 about 5.8 million people died of injuries worldwide, and injuries caused 16 percent of the global burden of disease (Krug, et al, 2000). In developed countries injuries are the leading cause of death between the ages of one and forty, and in the U.S. population it is the fourth leading cause of death (exceeded only by heart disease, stroke, and cancer). Of all deaths from injury in the United States, about 65 percent are classified as unintentional (which excludes deaths from suicide, homicide, and other criminal offenses); of these, about half result from motor vehicle accidents. Trauma also accounts for high...