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 25 On the Carpus

Why there are two rows of carpal bones

Nature constructed this justly, fashioning two rows of wrist bones particularly because the upper row [ossa carpi proximalis] (1-4 in nearly all the figs.) needed to be joined to the forearm in quite a different way than the lower row [ossa carpi distalis] (5-8 in all figs.) needed to be joined to the metacarpus and the first bone of the thumb. The carpus is articulated to these as separate and distinct bones while it articulates with the forearm as to a single bone, so that the bones of the upper row are rightly articulated with each other more closely and intimately than the bones of the lower row, and without the intervention of any body. 22 Anatomists believe this is the chief reason for the large number of wrist bones, adding as a secondary reason that it is difficult to hurt; they believe the wrist is made more resistant to injury because it is composed of many bones that break the force of objects that strike it by giving way, as we observe that a spear or arrow has more trouble penetrating loose targets than those that are taut. 23 At the same time, we notice that this strength and abundance of bones was constructed by Nature not least for a countless variety of motions of the hand. I shall now endeavor to explain what depressions and outgrowths the wrist bones have. 24



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 25 On the Carpus