7g. Intermetatarsal Articulations
(Articulationes Intermetatarseæ) The base of the first metatarsal is not connected with that of the second by any ligaments; in this respect the great toe resembles the thumb. |
| The bases of the other four metatarsals are connected by the dorsal, plantar, and interosseous ligaments. |
| The Dorsal Ligaments (ligamenta basium [oss. metatars.] dorsalia) pass transversely between the dorsal surfaces of the bases of the adjacent metatarsal bones. |
| The Plantar Ligaments (ligamenta basium [oss. metatars] plantaria).—The plantar ligaments have a similar arrangement to the dorsal. |
| The Interosseous Ligaments (ligamenta basium [oss. metatars.] interossea).—The interosseous ligaments consist of strong transverse fibers which connect the rough non-articular portions of the adjacent surfaces. |
| Synovial Membranes (Fig. 360).—The synovial membranes between the second and third, and the third and fourth metatarsal bones are part of the great tarsal synovial membrane; that between the fourth and fifth is a prolongation of the synovial membrane of the cuboideometatarsal joint. |
| Movements.—The movement permitted between the tarsal ends of the metatarsal bones is limited to a slight gliding of the articular surfaces upon one another. |
| The heads of all the metatarsal bones are connected together by the transverse metatarsal ligament. |
| The Transverse Metatarsal Ligament.—The transverse metatarsal ligament is a narrow band which runs across and connects together the heads of all the metatarsal bones; it is blended anteriorly with the plantar (glenoid) ligaments of the metatarsophalangeal articulations. Its plantar surface is concave where the Flexor tendons run below it; above it the tendons of the Interossei pass to their insertions. It differs from the transverse metacarpal ligament in that it connects the metatarsal to the others. |
| The Synovial Membranes in the Tarsal and Tarsometatarsal Joints (Fig. 360).—The synovial membranes found in the articulations of the tarsus and metatarsus are six in number: one for the talocalcaneal articulation; a second for the talocalcaneonavicular articulation; a third for the calcaneocuboid articulation; and a fourth for the cuneonavicular, intercuneiform, and cuneo-cuboid articulations, the articulations of the second and third cuneiforms with the bases of the second and third metatarsal bones, and the adjacent surfaces of the bases of the second, third, and fourth metatarsal bones; a fifth for the first cuneiform with the metatarsal bone of the great toe; and a sixth for the articulation of the cuboid with the fourth and fifth metatarsal bones. A small synovial cavity is sometimes found between the contiguous surfaces of the navicular and cuboid bones. |