Charley-horse and Muscle spasm

Charley-horse noun - A muscular cramp (especially in the thigh or calf) following vigorous exercise.

Muscle spasm and charley-horse are semantically related. In some cases you can use "Muscle spasm" instead a noun phrase "Charley-horse".

Muscle spasm noun - A painful and involuntary muscular contraction.

Charley-horse and muscle spasm are semantically related. Sometimes you can replace phrase "Charley-horse" with "Muscle spasm", this phrases are similar.