Charley是个人名，horse是“马”，Charley horse是什么意思呢？请看对话：

    A: I didn’t sleep well last night because I woke up suffering from Charley horses.

    B: That could be the result of mineral depletion. Perhaps you need to take some dietary supplements like calcium.

    Note: “Charley horse” is an American expression of uncertain origin. It dates from the 1880s, and may have been originally baseball slang. It refers to a painful involuntary cramp in a leg muscle, usually that of an athlete, as a result of a muscular strain or a blow. In the United Kingdom, when people get cramp they call it just cramp. Why should cramp be called “Charley horse?” Here is a plausible story. The pitcher Charley Radbourne was nicknamed Old Hoss, who suffered this problem during a game in the 1880s; the condition was then named by putting together his first name and the second half of his nickname.