A joint injury is an injury to the area where two or more bones meet, such as the knee, elbow, shoulder, or ankle. A SPRAIN is a type of joint injury caused by a sudden or excessive stretching of the ligaments that connect the bones. Sprains can range from mild to severe and can cause pain, swelling, bruising, and difficulty moving the affected joint. Treatment for a SPRAIN typically includes rest, ice, compression, and elevation. In more severe cases, physical therapy or surgery may be necessary.