Charley horse

A charley horse is a term for a very painful involuntary cramp, most commonly occurring in the legs (usually located in the calf muscle) or foot, lasting anywhere from a few seconds to a couple of days. It may also refer to bruising of the quadriceps muscle of the thigh, or contusion of the femur.

Charley horse
Specialty	Sports medicine

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 of 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 hematoma or temporary paresis and antalgic gait as a result of pain.^[1]

Colloquially, taking a hit in the thigh area (thigh contusion) can also be referred to as a charley horse^[2] or even simply as a charley.^[3]

Etymology

The first known use of the term was in 1886^[4] in a West Virginia newspaper. The origination of the phrase is often attributed to two baseball players, Jack Glasscock and Joe Quest.^[5] However, its exact origins still remain unknown, which has led to numerous theories.

Cause

Charley horses have many possible causes directly resulting from high or low pH or substrate concentrations in the blood, including hormonal imbalances, dehydration, low levels of magnesium, potassium, or calcium (evidence has been mixed),^[6][7][8] side effects of medication, or, more seriously, diseases such as amyotrophic lateral sclerosis and neuropathy.^[9] Charley horses seem to be most common in individuals who engage in strenuous physical activities, such as those who work in construction or play sports. They are also a common suffering during pregnancy.^[10]

Treatment

Relief is given by massaging or stretching the leg or foot in the opposite direction of the cramp. Relief also comes from standing up, which serves to counter the muscle-tightening signal.^[11]