THE HOCK JOINT ; 243 
attached to the tibial by plantar and interosseous (astragalo-scaphoid) ligaments, and to the fibular 
tarsal by a short oblique (caleaneo-seaphoid) band. The fourth is attached to the fibular tarsal 
by interosseous and plantar (caleaneo-cuboid) ligaments. The (fused) first and second tarsals 
are connected with the fibular tarsal by a plantar (caleaneo-cunean) ligament. 
(4) The distal tarsal bones are connected with the metatarsus by tarso-metatarsal ligaments, 
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 jot. The mcevements 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 
Deep flexor 
Tibia 
Gastrocnemius tendon 
Tarsal tendon of 
biceps femoris 
Calcanean bursa Tibialis anterior 
Gastrocnemius 
bursa Peroneus tertius 
Tuber calcis 
Upper pouch of 
joint capsule 
Tibial tarsal bone 
: Tibio-tarsal joint cavity 
Interosseous ligament 4 
Joint capsule 
Plantar ligament Central tarsal bone 
Fourth tarsal bone Third tarsal bone 
Interosseous ligament 
Large metatarsal bone Distal annular ligament 
Suspensory ligament 
Check ligament 
Fie. 255.—Sacirrat Secrion oF Hock or Horse. 
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 slightly oblique, the lower part of the limb deviates somewhat outward during 
flexion. The iong 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. 
Bee remaining joints differ in no material respect from those of the thoracic 
