584 A MANUAL OF ANATOMY 



surface of the navicular bone to the middle third of the inner border 

 of the dorsal surface of the cuboid. 



The plantar ligament is a strong band which extends from the 

 outer part of the plantar surface of the navicular bone to the internal 

 part of the plantar surface of the cuboid. Its direction is forwards 

 and outwards. 



The interosseous ligament is also a strong band which extends 

 between the contiguous surfaces of the two bones. The navicular 

 and cuboid bones do not, as a rule, articulate directly with 

 each other by cartilaginous surfaces, and under these circum- 

 stances there is no synovial membrane at this joint. Sometimes, 

 however, the two bones come into actual contact, and then each has 

 a special articular facet, that on the navicular bone being situated 

 on its outer extremity, adjacent to the facet for the external cunei- 

 form, and that on the cuboid being situated on its internal surface, 

 behind the normal facet for the external cuneiform. When the 

 two bones are thus in actual contact the joint is provided with a 

 S5movial membrane which is continuous with that of the naviculo- 

 cuneiform articulation. 



V. Naviculo-cuneiform Joint. — This belongs to the class diar- 

 throsis, and to the subdivision arthrodia. The ligaments are dorsal, 

 plantar, and internal. 



The dorsal ligament is a strong, continuous sheet of fibres passing 

 from the dorsal surface of the navicular bone to the dorsal surfaces 

 of the three cuneiform bones. 



The plantar ligament extends between the plantar surface of the 

 navicular bone and the plantar surfaces of the three cuneiform 

 bones. To a large extent it derives its fibres from the adjacent 

 expansions of the tendon of the tibialis posticus. 



The internal ligament passes between the tuberosity of the navi- 

 cular bone and the inner surface of the internal cuneiform, and it 

 blends with the dorsal and plantar ligaments. 



VI. Intercuneiform Joints. — These belong to the class diarthrosis, 

 and to the subdivision arthrodia. The ligaments are dorsal, inter- 

 osseous, and plantar. 



The dorsal ligaments are two in number, and their fibres pass 

 transversely between the dorsal aspect of the middle cuneiform and 

 the dorsal aspects of the internal and external cuneiform bones. 



The interosseous ligaments are also two in number, and 

 are very strong. They are deeply placed, and pass between the 

 sides of the middle cuneiform and the contiguous sides of the 

 internal and external cuneiform bones in front of the articular 

 facets. They constitute the chief bond of union between the three 

 bones. 



The ligament between the middle and external cuneiform is 

 attached to the entire vertical extent of the contiguous surfaces, 

 whilst that between the middle and internal cuneiform is generally 

 limited to the inferior and anterior portions of the contiguous 

 surfaces. 



