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 33 On the Bones of the Foot

THE TARSUS

The Greeks give the name tarso/j to the series of four bones of the foot [ossa cuneiformia, os cuboideum] (1, 2, 3, 4 in figs. 1, 2, 12, 13; in the skeletons, d, e, f, g to b, c, and h, h) of which three are attached to the navicular bone and the fourth, which is like a cube [os cuboideum], to the calcaneus. However, the Greeks often use the name 70 not only for these bones, but they also generally refer to the entire upper part of the foot with the same word, as Galen always does in On Anatomical Procedures, writing that tendons, veins, arteries, and nerves which extend through the upper foot and go to the toes are borne along the tarsus. 71 A great many of the Latin authors also call this array of bones the planta; but since the name planta is more widely applied, I have thought it best to use the name tarsus, since the name seems more precise. 72 The analogy of the tarsus’ construction to that of the carpus (1-8 in the figures for ch. 25) is not obscure: the tarsus is comprised of four bones, the carpus of double the number. 73 For the organ of grasping needed to be assembled of more and smaller pieces, while the


page 148

instrument of walking required larger but fewer. 74

The three inner bones of the tarsus

The three inner bones of the tarsus [ossa cuneiformia], attached to the navicular bone on more or less flat surfaces (s, t, u in fig. 13), have no special names, but many call them collectively xalkoeidh/. 75

The fourth and outermost bone

The fourth [os cuboideum], situated on the outside, has been called kuboeide/j from the shape of a cube or tessera (though it has as it were eight sides). One side of it (x in fig. 13) is posterior [proximal], where it is joined to the calcaneus [facies articularis cuboidea] (i in fig. 7). The second (a, b in fig. 12) is anterior [distal], where it will be explained it is attached to two metatarsal bones (IIII, V in fig. 1) along a continuous surface. The third [medialis] (g in figs. 12, 13) is on the inner side, where it is articulated to the adjacent bone of the tarsus [os cuneiforme laterale]. The fourth (d in figs. 12, 13) faces the outside [lateralis] of the foot, and scarcely deserves being called a side, as it is rather obscurely flat. The fifth (e in figs. 12, 13) is superior, unconnected to any bone, but facing the upper [dorsal] part of the foot. The sixth [plantaris] (z, h in fig. 2, z in fig. 13) faces the ground, and is likewise unconnected to any bone. It is considerably more irregular than the other sides, and has an oblong depression of its own [sulcus tendinis m. fibularis longi] (h in fig. 2) upon which, by the supreme cleverness of Nature, the tendon of the seventh muscle [m. fibularis longus] (V, X in the 15th table of muscles) moving the foot is turned. Because some sides of this bone are in this way obscure and irregular and it does not exactly resemble a cube, the Arabs called it grandinosum from its uneven appearance and its resemblance to a hailstone. 76 Others still because of its complex shape gave it the same name as the wedgelike bone of the head [os sphenoideum] (fig. 8, ch. 6), calling it polu/morfon. 77 This bone of the tarsus (as we have previously noted) is articulated to the calcaneus and rests on the ground; the other three, together with the navicular, are elevated above the ground in order to make the foot concave and high in this area.

The shape and size of the tarsal bones are varied

The tarsal bones (compare those in the first fig. with those in fig. 2, and figs. 12 and 13), like the carpal, vary among themselves in shape and magnitude, and they are not extended evenly in the upper and lower areas. The cuboid bone and the first bone [os cuneiforme mediale], which occupies the inner side of the foot, are much greater than the two [os cuneiforme intermedium et laterale] held in the middle, and the larger of those two is the one [os cuneiforme laterale] attached to the cuboid bone, in the same way as the cuboid is also larger than the innermost bone. In addition, the cuboid bone inclines backward toward the calcaneus, while the innermost bone projects forward, much more toward the big toe [hallux] than the others. Of the middle bones, the one [os cuneiforme intermedium] that is closest to the innermost bone is short and not extended as far forward as the one attached to the cuboid bone. All of them joined together form an upper surface that is arched and rounded and a lower one that is concave and hollow, 78 as everyone knows is also useful for the foot. The two middle bones look somewhat like a wedge: where they face the upper part of the foot, they are rather wide and rounded, and where they form the sole of the foot, they look no less acute than if they were inserted like wedges between the innermost and outermost bones of the tarsus. The tarsal bone [os cuneiforme laterale] that is attached to the cuboid is especially sharp and extends farther into the lower part of the foot than the second which is connected to the innermost bone of the tarsus, because the tendon of the fifth muscle moving the foot (D, E and c, d in the 15th table of muscles) [m. tibialis posterior] is very strongly inserted into its process (q in fig. 13), that comes down here. Where they are attached to each other on their sides, the bones of the tarsus are not covered with smooth, slippery cartilage over the whole area of the connection, but only in the posterior surface of the sides next to the navicular bone. Elsewhere they stand somewhat apart from each other, coupled together by cartilaginous ligaments. 79



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 33 On the Bones of the Foot