Charley horse is a North American name for a muscle spasm. Charley horses can occur in virtually any muscle, but are most common in the legs. These spasms are marked by extremely uncomfortable muscle contractions, which can last from several seconds to a whole day.
It is uncertain how the term ‘charley horse’ arose, but the main theories relate to baseball. The earliest citation appears to be from The Fort Wayne Gazette, July 1887:
“Whatever ails a player this year they call it ‘Charley horse’.”
The text would seem to indicate the phrase was coined around that time. Another common theory about the source is about a lame horse called Charley pulling the roller on the Chicago White Sox ballpark in the 1890s. However, since that happened after the citation quoted above, we can be sure this theory is wrong.
A most believable tale is one that involves baseball player Joe Quest. First told in the Grand Rapids, Michigan Daily Democrat on 28 June 1889:
Years ago, Joe Quest was employed as an apprentice in the machine shop of Quest & Shaw in Newcastle, his father, who was one of the proprietors of the firm, had an old white horse by the name of Charley. Doing usage in pulling heavy loads had stiffened the animal’s legs so that he walked as if troubled with strained tendons. Afterwards, when Quest became a member of the Chicago club, he was troubled, with others, with a peculiar stiffness of the legs, which brought to his mind the ailment of the old white horse Charley. Joe said that the ball players troubled with the ailment hobbled exactly as did the old horse, and as no one seemed to know what the trouble was, Quest dubbed it “Charley horse.”
Another one that might be true: The baseball pitcher Charley Radbourne was nicknamed Old Hoss. He got cramp during a baseball game in the 1880s. The condition was named by putting together his first name and the second half of his nickname.
Again, from the baseball fraternity, it’s said that a group of baseball players bet on a horse named Charley who came up lame in the home stretch. The next day, when a player suffered from a muscle pull in the leg, it was dubbed ‘Charley horse.’
So pick your favorite explanation and avoid getting a charley horse if you can. I know from experience how painful they can be.