The uppermost part of the greave, where it widens to cover the knee, is often decorated with a figural motif. The gorgoneion (Gorgon's face) is particularly appropriate in view of its round shape and power to transfix the enemy.
Metropolitan Museum of Art. 1991. "One Hundred Twenty-first Annual Report of the Trustees for the Fiscal Year July 1, 1990 through June 30, 1991." Annual Report of the Trustees of the Metropolitan Museum of Art, 121: p. 32.