308 ARTICULATIONS. 



side of the astragalus. The deeper layer consists of a short, thick, and strong 

 fasciculus, which passes from the apex of the malleolus to the inner surface of 

 the astragalus, below the articular surface. This ligament is covered by the 

 tendons of the Tibialis Posticus and Flexor Longus Digitorum muscles. 



The External Lateral Ligament (Fig. 211) consists of three fasciculi, taking 



Fig. 211. Ankle-joint : Tarsal and Tarso-metatarsal Articulations. External View. 



Right Side. 



NFERIOR TIB10-FIBULAH 

 &RTIC" 



ANKLE-JOINT 



TARSAL ARTIC"? 



TARSO-METATARSAL AHTICIJ 



different directions, and separated by distinct intervals ; for which reason it is 

 described by some anatomists as three distinct ligaments. 1 This would seem 

 the preferable description, were it not that the old nomenclature has passed 

 into general use. 



The anterior fasciculus, the shortest of the three, passes from the anterior 

 margin of the summit of the external malleolus, downwards and forwards, to 

 the astragalus, in front of its external articular facet. 



The posterior fasciculus, the most deeply seated, passes from the depression 

 at the inner and back part of the external malleolus to the astragalus, behind 

 its external malleolar facet. Its fibres are almost horizontal in direction. 



The middle fasciculus, the longest of the three, is a narrow rounded cord, 

 passing from the apex of the external malleolus downwards and slightly back- 

 wards to the middle of the outer side of the os calcis. It is covered by the 

 tendons of the Peroneus Longus and Peroneus Brevis. 



There is no posterior ligament, its place being supplied by the transverse 

 ligament of the inferior tibio-fibular articulation. 



The Synovial Membrane invests the inner surface of the ligaments, and sends 

 a duplicature upwards between the lower extremities of the tibia and fibula 

 for a short distance. 



Relations. The tendons, vessels, and nerves in connection with the joint are, 

 in front, from within outwards, the Tibialis Anticus, Extensor Proprius Pollicis, 

 anterior tibial vessels, anterior tibial nerve, Extensor Communis Digitorum, 

 and Peroneus Tertius ; behind, from within outwards, Tibialis Posticus, Flexor 

 Longus Digitorum, posterior tibial vessels, posterior tibial nerve, Flexor Longus 



1 Humphry, on the " Skeleton," p. 559. 



