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ARTICULATION OF THE TARSAL BONES. 



is supplied by an extension of the membrane which invests the 

 articulating surfaces of the astragalus and naviculare. 



The connexion of the astragalus, with the os calcis is sup- 

 ported by the lateral ligaments of the ankle joint, and also by 

 many irregular ligamentous fibres. 



Articulation of the Astragalus with the Os Naviculare. 



This articulation appears calculated for considerable motion, 

 as well from the form of the two surfaces concerned in it, as 

 the perfect state of their articulating investments. Their mo- 

 tions are restrained to a certain degree, by ligaments, which are 

 situated on the upper and internal surfaces of the foot. 



Fig. 10.* On the upper surface of the foot, is a 



thin broad ligament formed of parallel and 

 oblique fibres, stretched from the upper and 

 inner face of the astragalus to the upper 

 surface of the scaphoides or naviculare ; 

 some of the fibres extend even to the cunei- 

 forme bones. 



On the under surface of the foot, these 

 bones are connected by two ligaments, cal- 

 caneo-scaphoid internum, and externum. 

 The internal arises from the inner margin 

 of the lesser apophysis of the os calcis, and 

 runs obliquely forwards and inwards, to be 

 inserted on the inner and under surface of 

 the os naviculare. It is a strong ligament, 

 and contributes much to the preservation of 

 the arched form of the foot. On its under 

 surface is a trochlea for the tendons of the flexor pollicis and 



* The ligaments of the sole of the foot. 1. The os calcis. 2. The astragalus. 

 3. The tuberosity of the scaphoid bon . 4. The long calcaneo-cuboid ligament. 

 5. Part of the short calcaneo-cuboid ligament. 6. The internal calcaneo-sca- 

 phoid ligament. 7. The plantar tarsal ligaments. 8, 8. The tendon of the 

 peroneus longus muscle. 9, 9. Plantar tarso-metatarsal ligaments. 10. 

 Plantar ligament of the metatarso-phalangeal articulation of the great toe ; the 

 same ligament is seen upon the other toes. 11. Lateral ligaments of the meta- 

 tarso-phalangeal articulation. 12. Transverse ligament. 13. The lateral liga- 

 ments of the phalanges of the great toe ; the same ligaments are seen upon the 

 other toes. 



