"Acromion" in ancient Greek medical writers.

"Acromion" is one of many anatomical terms derived from ancient Greek: it is a transliteration of the Greek word dxp ptov (akromion). For the modern anatomist "acromion" has a precise meaning: "The lateral extension of the spine of the scapula, forming the highest point of the shoulder."' For the ancient Greek writers after Hippocrates, however, the meaning of ezicpd'ltov was a matter of doubt and dispute. The dispute was not merely a linguistic one, but arose from ignorance of the exact structure of the bones within the shoulder area, and particularly of the joint between the scapula and clavicle. From the ancient sources down to and including Galen it is clear that the human shoulder had never been dissected. The ancient knowledge of it was derived principally from external examination, supplemented by a study of shoulder injuries. It is worth noting here what an examination by palpation reveals. The clavicle can be followed along its entire length, starting from the medial end and ending near the tip of the shoulder. The spine of the scapula can also be followed up its whole length to near the tip of the shoulder. Here the two bones merge to form a single wider whole which extends right to the tip; but it is impossible to tell from palpation exactly where or how the joint is made. This uncertainty underlies the meaning and usage of dKp6ptoV in ancient Greek. The word itself is derived from dipog (omos) ="shoulder" + an adjective d?KpOc (akros) whose root means "end, tip, point". Its earliest appearance is in the Hippocratic corpus (fifth to fourth centuries B.C.).2 It occurs principally in the treatise On joints with reference to the tip of the shoulder, which is distinguished from the shoulder area as a whole (d&po) and the area on top of the shoulder (tiwJpi5). On joints contains a set of instructions for reducing a dislocated shoulder which depicts the surgeon as " . . . thrusting his head against the tip of the shoulder [dlcpd)ltov] to provide a point of resistance .... s8