THE CUNEIFORM BONES. 239 
great toe in front, and the fore and inner part of the navicular behind. Its upper, 
lower, and interna! surfaces are contluent, and form a convexity from above down- 
wards, which is most pronounced inferiorly, {Te Marana oar: 
where it is turned towards the plantar side of [\. 1. Merararsac 
the foot. On the fore part of the inner aspect yr, Merararsat 
of the bone there is usually a distinct oval im- : 
pression, which indicates the surface of insertion 
_of a portion of the tendon of the tibialis anticus 
muscle. Hlsewhere, this surface is rough for 
ligamentous attachments. The external surface 
of the bone, quadrilateral in shape, is directed 
towards the middle cuneiform; but as it ex- IV. Mera. 
ceeds it in length, it also comes in contact with rr 
the inner side of the base of the second meta- 
| tarsal bone. Running along the posterior and 
: : : : Fic. 181.—-ANTERIOR VIEW OF THE THREE 
moper edges of this area is an ---shaped articular Cgygironm Bones or THE RicuT Foor, 
) surface, the fore and upper part of which is for 
the base of the second metatarsal bone, the remainder articulating with the inner 
side of the middle cuneiform. The non-articular part of this aspect of the bone is 
. rough for the attachment of the strong interosseous ligaments, which bind it to 
“the middle cuneiform and second metatarsal bones respectively. The posterior or 
| IL Merararsar proximal end of the 
bone 1s provided 
with a pyriform. 
facet which fits on 
MIDDLE CUNEIFORM 
I. Mera-_ | Z ‘ : 
TARSAL = the inner articular 
5 E area of the navi- 
| Z = cular. Anteriorly 
; 5 the vertical dia- 
_ IMPRESSION x ; , 
"YOR TENDON 7. meter of the bone 
_ OF TIBIALIS : + 
Re aaricos is much increased, 
and the facet for 
A the base of the 
1G. 182.—THE RicHT INTERNAL Fic. 183.—THE RicHt INTERNAL ee f2 , 
CuNEIFoRM (Inner Side). CuNEIFORM (Outer Side). metatarsal bone of 
the great toe is 
consequently much larger than that for the navicular. The metatarsal facet is 
usually of semilunar form, but not infrequently is more reniform in shape, and 
may in some cases display complete separation into two oval portions. 
_ The middle or second cuneiform (0s cuneiforme secundum) is of a typical 
wedge shape; shorter than the others, it lies between them, articulating with the 
base of the second metatarsal in TLOTLG, Gi ait ray 
and the middle facet on the anterior sur- Merararsar cunrirorm 
face of the navicular behind. Its upper 
aspect, which corresponds to the base of 
the wedge, conforms to the roundness of 
the instep, and is slightly convex from 
side to side, affording attachments for the 
dorsal ligaments. Its under surface is 
narrow and tubercular, forming the edge 
of the wedge; with this the plantar liga- he 
Beer are connected \Dhevinner sur face : ne ae ae Higua Big. Adis t ae Bien 
: : : . : : MIDDLE CUNEIFORM MIDDLE CUNEIFORM 
quadrilateral in outline, is furnished with — (Inner side). (Outer Side). 
an[--shapedarticularareaalongitsposterior 
and superior borders in correspondence with the similar area on the outer side of 
the internal cuneiform. The rest of this aspect is rough for ligaments. The outer 
side displays a facet arranged along its posterior border, and usually somewhat con- 
stricted in the middle; this is for the external cuneiform. In front of this the 
bone is rough for the interosseous ligaments, which bind the two bones together. 
The proximal end is provided with a triangular f facet slightly concave from above 
EXTERNAL CUNEIFORM 
NAVICULAR 
Il. Merara RSA L 
