THE HOCK JOINT 



243 



attached to the tibial by plantar and interosseous (astragalo-scaphoid) ligaments, and to the fibular 

 tarsal by a short obhque (calcaneo-scaphoid) band. The fourth is attached to the fibular tarsal 

 by interosseous and plantar (calcaneo-cuboid) hgaments. The (fused) first and second tarsals 

 are connected with the fibular tarsal by a plantar (calcaneo-cunean) ligament. 



(4) The distal tarsal bones are connected with the metatarsus by tarso-metatarsal Ugaments, 

 which are not distinct from the common ligaments, except in the case of the interosseous ligament 

 between the third tarsal and metatarsal bones. 



Movements. — These are flexion and extension, which take place at the tibio- 

 tarsal joint. The movements between the tarsal bones, and between the latter 

 and the metatarsus, are so limited as to be negligible so far as the action of the joint 

 as a whole is concerned. In the standing position the articular angle (in front) 



Superficial flexor tendon 



Gastrocnemius tendon 



Tarsal tendon of 

 biceps fetnoris 



Calcanean bursa 



Gastrocnemius 

 bursa 



Tuber colds 



Upper pouch of 

 joint capsule 



Tibial tarsal bone 



Interosseous ligame 

 Plantar ligament 

 Fourth tarsal bone 



Interosseous ligament 

 Large metatarsal bone 



Suspensory ligament 

 Check ligament 



Deep flexor 

 Tibia 



Tibialis anterior 



Peroneus tertius 



Tibio-tarsal joint cavity 

 Joint capsule 

 Central tarsal bone 

 Third tarsal bone 



Distal annular ligament 



Fig. 2.55. — Sagittal Section of Hock of HosaE. 

 The section is cut so far laterally that the deep flexor tendon does not show. 



is about 150° to 160°. Complete extension is prevented by tension of the collateral 

 ligaments. Flexion is checked only by contact of the metatarsus with the leg,, 

 provided the stifle joint is also flexed. Owing to the fact that the axis of motion 

 is shghtly obhque, the lower paxt of the Hmb deviates somewhat outward during 

 flexion. The long collateral ligaments are tense in extension, the short ones in 

 flexion, of the joint. The movements of the hock joint must correspond with those 

 of the stifle on account of the tendinous bands in front and behind (peroneus tertius 

 and flexor superficialis) , which extend from the lower part of the femur to the tarsus 

 and metatarsus. 



The remaining joints differ in no material respect from those of the thoracic ' 



limb. 



