A letter to the editor in the Times by one R.J. Briggs suggests (inter alia):

Several years ago I was told by the curator of a museum in Athens how to identify an Ancient Greek statue from a Roman one. Because of the mountainous topography of Greece the models used by Ancient Greek sculptors were inevitably thin-ankled, those from Rome thick-ankled; climbing up steep hills stretches the Achilles tendon. We then toured the museum identifying the origin of statues using ankles as our criteria.

I'd never heard of that before, so I poked around ... and came up empty. But I did find this interesting tidbit from a thing on the Statue of Liberty:

Experts claim that up to 70% of the population have what is unofficially called Egyptian foot. This is characterized by a great toe longer than the second toe. About 20% have a so-called Greek foot where the great toe is shorter than the second toe, and the remainder have a square foot with the great toe and second toe the same length. The anatomical, political and ethnic logic ends there for the classic artist. As Roman statues sometimes are copies of the Greek originals, the Roman statues often have Greek feet.

FWIW and all that ...