CONFORMATION OF THE HOCK. 299 



594. Fracture of the Shoulder-blade. 



This accident is rare. In walking an animal trails the toe along the 

 ground. If, when the foot is brought forward, the hand be placed on 

 the shoulder, a crepitation will probably be felt. 



The fracture is usually across the neck ; and if so, the case is hopeless. 

 A longitudinal, but not a transverse, fracture in any other part may pos- 

 sibly with rest reunite evenly, and the animal may perhaps become 'sound. 



CHAPTER 37. 

 CONFORMATION OF THE HOCK. 



595. Importance of Conformation. 596. Structure of the Hock. 597. 

 Peculiarities of a good Hock. 598. Peculiarities of a badly formed Hock. 

 599. Disease intimately connected with defective Conformation. 



595. Importance of Conformation. 



A good shaped Hock is seldom unsound, whilst one of defective con- 

 formation readily becomes diseased if exposed to hard work. 



To know a good from a bad, a sound from an unsound hock requires 

 some time, trouble and attention, but not more than it is worth any 

 horseman's while to give. It is good practice to get the bones of a hock 

 to put them together, to examine the formation of each, and to feel them 

 when placed in their natural position ; and then to manipulate and com- 

 pare them with the prominences of the bones in the living animal, espe- 

 cially on the seat of Spavin. With a knowledge of conformation derived 

 from handling the bones, the satisfactory examination of the hock be- 

 comes easy. 



596. Structure of the Hock. 



The Hock consists of six bones, namely the astragalus, cuneiform 

 magnum, cuneiform medium, cuneiform parvum, cuboid, and os calcis. 

 The first five of these may be distinguished as weight-bearing bones, 

 whilst the os calcis or bone at the back acts as a lever to the tendons of 

 the leg. See Plate 22. 



The true hock-joint, however, is formed by only two bones, namely 

 the tibia or upper bone of the leg, and the astragalus. The other bones, 

 though they possess a limited amount of motion between each other, do 

 not enter into the true hock-joint. 



