LIGAMENTS OF TARSUS WITH METATARSUS. 



649 



Fig. 226. 



as they rise the interosseous and transverse plantar bands will keep them 

 united. 



In standing and in progression these bones are separated somewhat from 

 each other with diminution of the arch of the foot, and stretching of the 

 transverse ligaments which connect them. 



ARTICULATION OF THE MKTATARSAL BONES. The bases of the four 

 outer metatarsal bones are connected together by dorsal, plantar, and in- 

 terosseous ligaments ; and where their lateral parts 

 touch, they are covered with cartilage, and have 

 offsets of a synovial sac. 



The dorsal ligaments (fig. 22 G) are small trans- 

 verse bands from the base of one metatarsal bone 

 to the next. The plantar ligaments (fig. 224) are 

 similar to the dorsal. The interosseous ligaments 

 are short, transverse fibres between the contiguous 

 rough lateral surfaces : they may be afterwards 

 seen by forcibly separating the bones. 



Lateral union. The four outer bones touch one 

 another laterally ; the second metatarsal lies against 

 the internal and external cuneiforms ; and the 

 fourth is in contact internally with the outer cunei- 

 form. Those articulating surfaces are covered with 

 cartilage ; and are provided with synovial mem- 

 brane, which is derived from the sacs serving for 

 the articulation of the same four metatarsal with 

 the tarsal bones. 



The metatarsal bone of the great toe, like that 

 of the thumb, is not united to the others at its base 

 by any intervening bands. 



The digital ends of the five metatarsal bones are 

 united by the transverse metatarsal ligament ; this 

 has been described in page 624. 



TARSAL WITH METATARSAL BONES. These articulations resemble the 

 like parts in the hand, as there is a separate joint for the great toe, and a 

 common one for the four outer metatarsals. 



Articulation of the great toe. The articular ends of the bones are in- 

 cased by a capsule, and are provided with an upper and a lower longitu- 

 dinal band to give strength to the joint : the lower band is placed between 

 prolongations from the tendons of the tibialis anticus and peroneus longus. 



A simple synovial membrane serves for the articulation. 



The articular surfaces are oval from above down, curved inwards, and 

 constricted in the middle ; that of the great toe is excavated, and the other 

 is convex. 



Movement. There is an oblique movement of the metatarsal bone down 

 and in and up and out, like that of the internal cuneiform with the sca- 

 phoid bone ; and this will contribute some motion to inversion and ever- 

 sion of the foot. 



The joint possesses likewise slight abductory and adductory movement. 



Articulation of the four outer toes. The three outer tarsal bones of 

 the last row correspond with four metatarsals ; the middle cuneiform be- 

 ing opposite the second metatarsal bone, the external cuneiform touching 

 that of the third toe, and the os cuboides carrying the two outer bones. 



DORSAL LIGAMENTS UNI- 

 TING THE TARSUS TO THE 



METATARSUS, AND THE ME- 

 TATARSAL BONES TO EACH 

 OTHER BEHINI> (Bourgery). 



