THE BONES OF THE LOWER LIMB 



269 



of the tibialis posticus, and origin to a portion of the adductor 

 obliquus hallucis. The shaft gives origin to the second plantar 



External Sur&oe -- 

 Medullary Foramen 



.Jbitemal Surface 



_ .&. - For 3rd Metatarsal 



For External Cuneiform 

 (inconstant) 



For 5th Metatarsal For Cuboid 



Fig. 160. — The Fourth Right Metatarsal Bone. 

 A, External view; B, Internal view. 



interosseous, and partial origin to the third and fourth dorsal 

 interossei. 



Articulations. — Posteriorly with the cuboid, infernally with the 

 third metatarsal, and sometimes with the external cuneiform, 

 externally with the fifth metatarsal, and anteriorly with the first 

 phalanx of the fourth toe. 



Fifth Metatarsal Bone. — ^This supports the little toe. The base 

 is elongated from side to side, and compressed from above down- 

 wards. Its leading characteristic is a stout, mammillary process, 

 situated on its outer aspect, called the tuberosity, which is directed 

 outwards and backwards, and gives insertion to the tendon of the 

 peroneus brevis. The posterioi surface presents a triangular facet 

 for the cuboid, the plane of which is inclined inwards and forwards. 

 This facet does not encroach upon the tuberosity. The inner sur- 

 face presents a large semi-oval facet for the outer side of the base of 

 the fourth metatarsal. The dorsal surface, which is rough and 

 slightly convex, gives insertion, as a rule, to the tendon of the per- 

 oneus tertius. The plantar surface, which is rough and concave, 

 gives origin to the flexor brevis minimi digiti. The shaft gives 

 origin to the third plantar interosseous, and partial origin to the 

 fourth dorsal interosseous. 



Articulations. — Posteriorly with the cuboid, internally with the 

 fourth metatarsal, and anteriorly with the first phalanx of the little 

 toe. 



Each metatarsal bone presents a medullary foramen, that of 



