(Chapter 26) Footnote 2:

It is possible on Galen’s testimony that the sculptor Polyclitus used this word ( De placitis Hipp. et Plat. 5.3.15.8 = Polyclitus Testimonia 3.13); it is otherwise unattested in the TLG before the first century AD: see Rufus Ephesius De corporis humani appellationibus 81.1; it appears eight times in Soranus, and frequently in Galen. Canano’s and Vesalius’ postbrachiale is a Latinization of the Greek metaka/rpion; it does not appear in classical Latin.