Charley horse

A charley horse is an American term for a very painful involuntary cramp in the legs (usually located in the calf muscle) and/or foot, lasting anywhere from a few seconds to a couple of days. The phrase formerly referred more commonly to bruising of the quadriceps muscle of the anterior or lateral thigh, or contusion of the femur, that commonly results in a haematoma and sometimes several weeks of pain and disability. In this latter sense, such an injury is known as dead leg.^{[citation needed]}

Dead legs and charley horses are two different types of injuries: A charley horse involves the muscles contracting without warning, and can last from a few seconds to a couple days. A dead leg often occurs in contact sports, such as football, when an athlete suffers a knee or other blunt trauma to the lateral quadriceps causing a haematoma or temporary paresis and antalgic gait as a result of pain.^{[citation needed]}

Colloquially, taking a hit in the thigh area (thigh contusion) can also be referred to as a charley horse^[1] or even simply as a charley.^[2]