348 THE ARTICULATIONS, OR JOINTS 



The superior calcaneocuboid ligament (ligamentum calcaneocuboideum dorsals) 

 (Fig. 277) is a broad portion of the capsule which passes between the contiguous 

 surfaces of the os calcis and cuboid on the dorsal surface of the joint. 



The internal calcaneocuboid or the interosseous ligament (pars calcaneo- 

 cuboidea ligamenti bifurcati) is a short but thick and strong band of fibres arising 

 from the os calcis, in the deep hollow which intervenes between it and the astrag- 

 alus, and closely blended, at its origin, with the superior calcaneoscaphoid liga- 

 ment. These two ligaments are often regarded as a single bifurcated ligament 

 (ligamentum bifurcdtum). The internal calcaneocuboid ligament is inserted into 

 the inner side of the cuboid bone. This ligament forms one of the chief bonds 

 of union between the first and second rows of the tarsus. 



The long calcaneocuboid or long plantar or superficial long plantar ligament 

 (ligamentum plantare longum} (Fig. 279), the more superficial of the two plantar 

 ligaments, is the longest of all the ligaments of the tarsus; it is attached to the 

 under surface of the os calcis, from near the.tuberosities, as far forward as the 

 anterior tubercle; its fibres pass forward to be attached to the ridge on the under 

 surface of the cuboid bone, the more superficial fibres being continued onward 

 to the bases of the second, third, and fourth metatarsal bones. This ligament 

 crosses the groove on the under surface of the cuboid bone, converting it into a 

 canal for the passage of the tendon of the Peroneus longus. 



The short calcaneocuboid or short plantar ligament (ligamentum calcaneo- 

 cuboideum plantare") (Fig. 279) lies nearer the bones than the preceding, from which 

 it is separated by a little areolar tissue. It is exceedingly broad, about an inch 

 in length, and extends from the tubercle and the depression in front of it, on the 

 fore part of the under surface of the os calcis, to the inferior surface of the cuboid 

 bone behind the peroneal groove. 



Synovial Membrane (Fig. 280). The synovial membrane in this joint is distinct. It lines the 

 inner surface of the ligaments. 



Movements. The movements permitted between the os calcis and cuboid are limited to a 

 slight gliding upon each other. 



3. THE LIGAMENTS CONNECTING THE Os CALCIS AND SCAPHOID. 



Though these two bones do not, as a rule, directly articulate, they are con- 

 nected by two ligaments: 



Superior or External Calcaneoscaphoid. 

 Inferior or Internal Calcaneoscaphoid. 



The superior or external calcaneoscaphoid or calcaneonavicular ligament 

 (pars calcaneonavicularis ligamenti bifurcati) arises, as already mentioned, with 

 the internal calcaneocuboid in the deep hollow between the astragalus and os 

 calcis, constituting a part of the ligamentum bifurcatum; it passes forward from 

 the upper surface of the anterior extremity of the os calcis to the outer side of 

 the scaphoid bone. These two ligaments resemble the letter Y, being blended 

 together behind, but separated in front. 



The inferior or internal calcaneoscaphoid or calcaneonavicular ligament (liga- 

 mentum calcaneonaviculare plantare} (Fig. 279) is by far the larger and stronger of 

 the two ligaments between these bones; it is a broad and thick band of fibres, 

 \vhich passes forward and inward from the anterior margin of the sustentaculum 

 tali of the os calcis to the under surface of the scaphoid bone. This ligament not 

 only serves to connect the os calcis and scaphoid, but supports the head of the 

 astragalus, forming part of the articular cavity in which it is received. The 

 upper surface presents a fibrocartilaginous facet, lined with the synovial membrane 



