360 THE ARTICULATIONS OK JOINTS. 



The ligamenta tarsometatarsea plantaria are the weakest bands of the series, and 

 consist of scattered fibres passing from the cuboid to the bases of the two metatarsals. 

 Some fibres, which are almost transverse, extend from the third cuneiform to the 

 fifth metatarsal, and additional fibres reach the fifth metatarsals from the long 

 plantar ligament. 



Occasionally the tarsal end of the ligamentum cuneometatarseum interosseum 

 laterale is attached to the medial margin of the cuboid. 



The synovial stratum is restricted to this articulation, and merely sends a pro- 

 longation forwards between the opposing articular surfaces of the fourth and fifth 

 metatarsal bases. 



ARTICULATIONES INTERMETATARSE.E. 



The intermetatarsal articulations are found between adjacent lateral aspects 

 of the bases of the four lateral metatarsal bones. The articular facets are small, 

 oval, or rounded surfaces which occupy only a limited portion of the flattened con- 

 tiguous surfaces of the bones. Each joint is provided with an articular capsule, 

 which, however, is not a complete investment, because the three joint cavities are in 

 free communication on their proximal aspects with the tarso-metatarsal joint cavities 

 one with the lateral and two with the intermediate. The definite fibres of each 

 fibrous stratum are situated chiefly in the transverse direction 



The ligamenta basium dorsalia are short bands which extend from one base to 

 the other. 



The ligamenta basium plantaria and the ligamenta basium interossea are similarly 

 arranged, but the interosseous ligaments are the strongest and most important 

 members of this series. 



The synovial stratum of each capsule is an extension from the lateral and inter- 

 mediate tarso-metatarsal joints. 



Frequently a bursa is found between the bases of the first and second metatarsal bones. It 

 produces an appearance of indistinct facetting upon these bones, and it may communicate with 

 the first cuneo -metatarsal joint. 



The ligamentum metatarsale trans versum (transverse metatarsal ligament) lies upon, 

 and is attached to, the non-articular plantar aspects of the heads of all the meta- 

 tarsal bones. It differs from the corresponding ligament in the palm in the fact 

 that it binds all the metatarsal bones together, whereas in the palm the thumb is 

 left free. It is closely associated with the plantar fibrous plates of the metatarso- 

 phalangeal joints, to the plantar surfaces of which it contributes prolongations. 



ARTICULATIONES METATARSOPHALANGE^. 



Metatarso-phalangeal Joints. Each of these joints is a modified ball-and- 

 socket in which a shallow cup upon the bases of the first phalanges receives the 

 somewhat globular head of a metatarsal bone. 



Each joint retains a modified articular capsule which invests the joint. Its 

 only distinct bands of the fibrous stratum are the ligamenta collateralia. These are 

 strong cord-like bands which are situated on the medial and lateral sides of each 

 joint, where they extend between adjacent rough surfaces. 



On the dorsal aspect, ligaments distinct from the dorsal expansion of the ex- 

 tensor tendons can hardly be said to exist. The plantar aspect of the capsule 

 consists of a thick fibrous plate strengthened by transverse fibres to form the plantar 

 accessory ligament, which in the case of the great toe presents developed within it 

 two large sesamoid bones. In the other toes this plate remains fibrous throughout, 

 and is grooved on its plantar aspect for the accommodation of the long flexor 

 tendons. It will thus be seen that the metatarso-phalangeal joints are constructed 

 upon a plan very similar to that of the corresponding joints in the hand. 



A synovial stratum lines the capsule of each articulation ; and the epiphyseal 

 lines of the metatarsals and phalanges are extra-capsular. 



