254 ANATOMY OP THE LOWER EXTREMITY. 



shaped, from the tip of the malleolus, to be inserted into the 

 inner side of the astragalus, os calcis, and scaphoid bone. 

 The ligament is covered in by the internal annular ligament 

 (p. 244), and the tendons which pass through it. 



The external lateral ligament consists of three strong 

 fasciculi; the anterior of which passes from the anterior 

 border of the malleolus to the surface of the astragalus 

 in front of it ; the middle descends from the tip of the mal- 

 leolus to the side of the os calcis, and the posterior from 

 the posterior border of the malleolus, horizontally back- 

 ward, to the posterior surface of the astragalus. 



The tarsal bones of the foot are united by dorsal, plantar, 

 and interosseous ligaments. 



The dorsal ligaments unite each tarsal bone with those 

 contiguous to it ; several strong bands pass forward from 

 the deep fossa between the astragalus and os calcis, to the 

 scaphoid and cuboid bones, under the name of calcaneo- 

 cuboid and astragalo-scaphoid ligaments. 



The plantar ligaments also consist of short bands uniting 

 the contiguous bones, with the addition, however, of two 

 others of large size and great strength. The inferior cal- 

 caneo-scaphoid ligament unites the os calcis and the scaphoid 

 bone, forming part of the cavity which receives the rounded 

 head of the astragalus; the tendon of the tibialis posticus 

 crosses this ligament. The long calcaneo-cuboid ligament 

 passes from the under surface of the os calcis to the rough 

 ridge on the under part of the cuboid bone; some of its 

 fibres continue over the tendon of the peroneus longus, 

 forming a sheath for it, and are inserted into the bases of 

 the third and fourth metatarsal bones; these last-named 

 fibres are sometimes called the ligamentum longum plantse, 

 and the shorter ones the ligamentum breve plantse. 



The interosseous ligaments are five in number, and are 

 strong bands intervening between the contiguous surfaces 

 of the adjoining tarsal bones. The caloaneo-astragaloid lies 

 in the fossa between the os calcis and astragalus, and can 

 only be seen by a longitudinal section of the two bones, 

 when it will be found as a short, stout band, attached to a 

 depression in each bone. Another interosseous ligament 

 exists between the articulating surfaces of the cuboid and 

 scaphoid bones, and three others between the three cunei- 

 form and the cuboid bones. 



The bases of the metatarsal bones are united by dorsal, 

 plantar, and interosseous ligaments ; the interosseous liga- 



