Myalgia - muscle pain.
From the Greek prefix and suffix:
- Myo - word-forming element meaning "muscle," from combining form of Greek mys for "muscle," literally translating to "mouse" (as in "little mouse under the skin") - etymology online
- algia - word-forming element denoting "pain," from Greek algos "pain," . Related to alegein (of unknown origin) "to care about," originally "to feel pain." - etymology online