TALOCRURAL ARTICULATION OR ANKLE-JOINT 



351 



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ercle on its posterior surface, medial to the groove for the tendon of the Flexor 

 hallucis longus. The deep fibers (anterior talotibial) are attached, above, to the 

 tip of the medial malleolus, and, below, to the medial surface of the talus. The 

 deltoid ligament is covered by the tendons of the Tibialis posterior and Flexor 

 digitorum longus. 



The anterior and posterior talofibular and the calcaneofibular ligaments were 

 formerly described as the three fasciculi of the external lateral ligament of the 

 ankle-joint. 



The Anterior Talofibular Ligament (ligamentum talofibulare anterius) (Fig. 355). 



The anterior talofibular ligament, the shortest of the three, passes from the 

 anterior margin of the fibular malleolus, forward and medially, to the talus, in 

 front of its lateral articular facet. 



The Posterior Talofibular Ligament (ligamentum talofibulare postering) (Fig. 355). 



The posterior talofibular ligament, the strongest and most deeply seated, runs 



almost horizontally from the depression at the medial and back part of the fibular 



malleolus to a prominent tubercle on the posterior surface of the talus immediately 



lateral to the groove for the tendon of the Flexor hallucis longus. 



The Calcaneofibular Ligament (ligamentum calcaneofibular e) (Fig. 355). The 

 calcaneofibular ligament, the longest of the three, is a narrow, rounded cord, run- 

 ning from the apex of the fibular malleolus downward and slightly backward to a 

 tubercle on the lateral surface of the calcaneus. It is covered by the tendons of 

 the Peronsei longus and brevis. 



Anterior talofibular ligament 



Posterior talofibular ligament 

 Calcaneofibular ligament 

 Lateral talocalcaneal ligament 



Anterior 



talocalcaneal 



ligament 



Fia. 356. Capsule of left talocrura articulation (distended). Lateral aspect. 



Synovial Membrane (Fig. 356). The synovial membrane invests the deep surfaces of the 

 ligaments, and sends a small process upward between the lower ends of the tibia and fibula. 



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

 medial side, the Tibialis anterior, Extensor hallucis proprius, anterior tibial vessels, deep peroneal 

 nerve, Extensor digitorum longus, and Peronseus tertius; behind, from the medial side, the Tibialis 

 posterior, Flexor digitorum longus, posterior tibial vessels, tibial nerve, Flexor hallucis longus; 

 and, in the groove behind the fibular malleolus, the tendons of the Peronaei longus and brevis. 



The arteries supplying the joint are derived from the malleolar branches of the anterior tibial 

 and the peroneal. 



The nerves are derived from the deep peroneal and tibial. 



Movements. When the body is in the erect position, the foot is at right angles to the leg. 

 The movements of the joint are those of dorsiflexion and extension; dorsiflexion consists in the 



