Sprain (Overview)

Off the playing field, sprains often occur because of high-impact accidents - for example, when a front-seat passenger's knee is struck by the dashboard during a head-on car crash or when a pedestrian slips on a patch of ice and lands on a wrist or shoulder. In the workplace, strains, sprains and tears, involving joints and related structures, are also common, with more than 750,000 cases reported to the U.S. Bureau of Labor Statistics each year.

Symptoms

In general, sprains cause pain and swelling in the injured joint, along with some local joint tenderness. In moderate or severe sprains, there can also be deformity (a change in the joint's normal contour) and a noticeable change in the joint's function. This change in function can include a feeling that the joint is unstable or unreliable (for example, the knee feels as if it will buckle or give out), a feeling that the joint is too loose or that the bones are not aligned in their normal positions, or a change in the joint's normal range of motion.

Other symptoms depend on the joint involved and the ligament that has been injured. For example, a sprain of the knee's anterior cruciate ligament can sideline an athlete immediately because of severe pain, swelling and a feeling that the knee will give out. A sprain of the knee's posterior cruciate ligament, however, may cause only mild swelling that does not stop the athlete from continuing play.