A charley horse is the bruising of the quadriceps muscles at the front of the thigh due to a blow that crushes the muscles against the underlying femur (thigh bone). There is usually pain at the time of the injury and sometimes swelling and tingling.
Later, the pain and swelling become worse, a bruise appears, and the injured muscle may become stiff, restricting movement.
Treatment for a charley horse is with PRICE (Protection, Rest, Ice, Compression, Elevation). A doctor may also recommend physical therapy.