charley horse

A charley horse is an involuntary muscle spasm or cramp, usually occurring in the larger muscles of the limbs. It can last anywhere from a few seconds to more than a day—and can really hurt.

Charley horse is popularly spelled Charlie horse or charlie horse. 

The ultimate origin of the term charley horse is murky, but it first appears in the context of baseball in the 1880s. Back then, baseball players called various muscle injuries, including cramps, bruising, and other pains and sores, charley horses.

One story says the term comes from a lame horse, named Charley, that pulled equipment at the Chicago White Sox’s in the late 19th century. Poor Charley’s limping stride became so familiar to the baseball players that, whenever one of them sustained a muscular injury in the lower body that made it hard to walk, they called it a charley horse.

Another tale goes that the term originated with Charley “Old Hoss” Radbourn, a National League pitcher notably afflicted with leg cramps and muscle pain in the late 1880s. Charley horse combined Radbourn’s first name and altered the second part of his nickname.

While originating as an Americanism, charley horse spread to other varieties of English over the 20th century. It also spread into popular culture. Milton Bradley included a charley horse injury in his 1965 game Operation, in which a person earns big points by removing a tiny plastic horse from the slot. Note: This, of course, is not how to treat an actual charley horse. Doctors say to stretch, massage, or ice the cramping muscle, not to try and pull a little horse out of it. Charlie Horse, punningly, was the name of a character on the 1990s children’s puppet show, Lamb Chop’s Play-Along!

Charley horses often occur late at night while a person is sleeping. This is usually due to either an awkward position of the body or a vitamin deficiency that causes muscles to cramp after being relaxed for a period of time.

Usually, a charley horse will resolve itself with time and treatment. However, if it persists, it may be smart to go to a doctor. Although it is best known as a runner or athlete’s injury, charley horses are also known to very inopportunely sneak up all sorts of people in everyday activities.

More examples of charley horse:

“I stretched my legs out last night while I was sleeping and got a Charlie horse so bad down my whole bottom leg, and I still feel the muscle pull now, hours later. 😂”
—@AquaPoppie, July 2018

“She said heat cramps will present similar to a charlie horse or muscle cramp. She said people with heat cramps need to get out of the sun and drink water.”
—Bob Gross, The Times Herald, June 2018

This content is not meant to be a formal definition of this term. Rather, it is an informal summary that seeks to provide supplemental information and context important to know or keep in mind about the term’s history, meaning, and usage.