Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 21 On the Scapuli

Posterior surface or dorsum of the scapula

The posterior surface of the scapula (fig. 2), furnished with a conspicuous, spiny process (G, H, I, K, L 56 in fig. 2), is convex if casually observed, for Nature would not have been unaware that this shape is better adapted to enduring injuries without harm. But if we study this protrusion of the scapula more closely, two concave surfaces will come to our attention that are perfectly suited to receive muscles. One [fossa infraspinata] (between G, H, D, S, T, and Y in fig. 2) lies beneath the spine of the scapula between the lower surface of the spine and the swelling, thicker part of the lower side of the scapula. The other [fossa supraspinata] (between Z, a, I, G, and especially between b and c in fig. 3) is between the upper surface of the scapular spine and the upper side of the scapula. A certain muscle [m. supraspinatus] (k in the 6th table of muscles, G in the 11th) occupies this surface; we shall declare it the third 57 of the muscles that rotate the arm. The lower cavity is filled by a muscle [m. infraspinatus] (G in the 11th table of muscles) which will be counted the second of the muscles that rotate the arm. 58 Although this outer or posterior surface of the scapula shows these two cavities on account of the spine of the scapula as well as its sides, nevertheless the whole (since it is seen to swell out) was called the back or dorsum of the scapula by the ancients, borrowing from its likeness to the actual human dorsum. Now the process that arises from this dorsum of the scapula 59 they called the spine for its resemblance to the posterior processes of the vertebrae, or spines, 60 and since these were quite rightly established as such by the ancients, I shall not stray so much as a fingernail’s breadth from these names. I shall call the outer surface of the scapula the dorsum, and the root of the acromion I shall call the spine of the scapula.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 21 On the Scapuli