TARSAL ARTICULATIONS. 



161 



There is also an external ligament, consisting of a slight fasciculus of fibres, 

 which descends perpendicularly from the outer surface of the astragalus 

 to the external side of the calcaneum, parallel with the middle division 

 of the external lateral ligament of the ankle-joint. It may be farther 

 observed, that those portions of the lateral ligaments of the ankle-joint 

 which pass down over the astragalus to the os calcis assist in uniting 

 these two bones. 



Calcaneo-scaphoid ligaments. The calcaneum and scaphoid bone are not in 

 contact, but they are connected by two ligaments. The inferior or plantar 

 ligament, much the larger of the two, is a broad baud which passes forwards 

 and inwards from the fore-part of the calcaneum (sustentaculum 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 of the cavity just mentioned, and lies deeply 

 at the anterior part of the fossa (sinus pedis), between the astragalus and 

 os calcis. Its fibres, very short, are directed from behind forwards between 

 the contiguous extremities of the bones. They are attached posteriorly 

 to a ridge of the os calcis that separates the articular surfaces for the 

 astragalus and os cuboides, and anteriorly to 

 the outer side of the scaphoid bone. 



Fig. 148. LIGAMENTS OP THE FOOT, SEEN FROM 



BELOW. g 



1 and 2, portions of the internal lateral ligament 

 of the ankle-joint descending upon the calcaneum ; 

 3, calcaneo -cuboid or long plantar ligament ; 3', deep 

 or short part of the same ; 4, plantar calcaneo-sca- 

 phoid ligament ; 5, three scaphoido-cuneifonn liga- 

 ments of the internal, middle and external cuneiform 

 bones ; 6, is placed upon the external cuneiform bone, 

 towards which is seen coming from behind a cuboido- 

 cuneiform ligament ; 7, is placed upon the internal 

 cuneiform bone ; from 6 and 7, are seen passing down- 

 wards the plantar cuneo-metatarsal ligaments; x , part 

 of the first dorsal cuneo-metatarsal ligament; 8 and 9, 

 ligamentous fibres prolonged from the cuboid bone 

 and sheath of the peroneus longus muscle upon the 

 outer metatarsal bones ; 10, 10, between these figures 

 the posterior intermetatarsal (or transverse) ligaments ; 

 11, 11, anterior transverse metatarsal ligament, con- 

 tinued across the four metatarsal spaces ; 12, inter- 

 sesamoid ligament ; 13, 13, between these figures are 

 seen the five pairs of internal and external lateral 

 metatarso-digital ligaments; 14, 14, between these 

 figures are seen the five pairs of internal and external 

 lateral digital (phalangeal) ligaments of the first 

 series ; those of the second series have no figure placed 

 to mark them ; 15, inferior ligament of the phalangeal 

 articulation of the great toe. 



u 



The talo-scaplioid or astragalo-scapJioid liga- 

 ment, a membranous band of fibres situated 



on the dorsuin of the foot, extends obliquely forwards from the anterior 

 extremity of the astragalus to the superior surface of the scaphoid bone, 

 and completes the capsule of the calcaneo-talo-scaphoid joint, formed in the 

 rest of its extent by the plantar and external calcaueo-scaphoid ligaments. 



