TAP.SAL ARTICULATIONS 



175 



Boxes one with axothek. — The astragalas is connected with the 

 calcanenm by two synovial articulations, viz., by a posterior one pecu- 

 liar to those two bones, and by an anterior one common to them with 

 the scaphoid bone. The following are the principal parts requiring- 

 description. 



Astragalo-calcaneal ligaments. — The interosseous ligament, broad 

 and strong, passes vertically downwards from the groove between the 

 anterior and posterior articular surfaces of the astragalus to the similar 

 groove between the corresponding articular surfaces of the calcaneura, 

 A membranous posterior tigeonent connects the posterior border of the 

 astragalus with the upper surface of the calcaneum ; its fibres are 

 oblique and very short. There is also an cxterneil ligament, consisting 

 of a slight fasciculus of fibres, which descends perpendicularly from the 

 cuter surface of the astragalus to the outer side of the calcaneum, 

 parallel with the middle division of the external lateral ligament of the 

 ankle-joint. It may be further observed, that those portions of the 

 fcoSj, lateral Jigamcnt* of the ankle-joint which pass down over the astragalus 



to the OS calcis assist in uniting these two bones. 



Fig. 157. — Ligaments of the Foot, seen from 

 BELOW. (A. T.) I 



1 aud 2, poi-tions of the internal lateral ligament 

 of the ankle-joint ; 3, calcanco-cuLoid or long plantar 

 ligament ; 3', deep or ^liort part of the same ; 4, 

 jilantar calcaneo-scaphoid ligament ; 5, three scaphoido- 

 cuneiform ligaments of tlie internal, middle and ex- 

 ternal cuneiform bones; 6, is placed upon the external 

 cuneiform bone, towards which is seen coming fi'om 

 behind a cuboido-cuneiform ligament ; 7, is placed 

 upon the internal cuneiform bone ; from 6 and 7, are 

 seen ijassing downwards the plantar-cunco-metatarsal 

 ligaments ; x , part of the first dorsal cuneo-metatarsal 

 ligament ; 8 and 9, ligamentous fibres prolonged from 

 the culjoid bone and sheath of the i^eroneus longus 

 muscle upon the outer metatarsal bones ; 10, 10, be- 

 tween these figures the }:rOsterior intermetatarsal (or 

 transverse) ligaments ; 11, 11, anterior transverse 

 metatarsal ligament, continued across the four meta- 

 tarsal spaces ; 12, intersesamoid ligament ; 13, 13, 

 between these figures are seen the five pairs of internal 

 and external lateral metatai-so-digital ligaments ; 14, 

 14, between these figures are seen the five pairs of 

 internal and external lateral digital (idialangeal) liga- 

 ments of the first series ; those of the second series 

 have no figure placed to mark them ; 15, inferior liga- 

 ment of the phalangeal articulation of the great toe. 



Calcaneo-scaphoicl ligaments. — The 



calcaneum and scaphoid bone are not in 

 contact, but they arc connected by two 

 ligaments. The inferior or pt^'^ntnr liga- 

 ment, much the larger of the tAvo, is a" broad band which passes for- 

 wards and inwards from the fore part of the calcaneum (susten- 

 taculum tali) to the inferior surface of the scaphoid bone. It is in 

 contact inferiorly with the tendon of the tibialis posticus muscle, while 

 superiorly it forms the floor of the articular cavity which receives 

 the head of the astragalus, and is lined by synovial membrane. The 

 external, dorsal, or interosseous ligament, forms the external boundary 



