30 Veterinary Elements. 



The hock joint is straightened (extended) by the mus- 

 cles of the gaskin (gastrocneniii) which have their origin 

 on the lower part of the thigh bone, one has its insertion 

 to the point of the hock, the other to the bones of the 

 pastern and foot; the latter when extending the hock 

 flexes the fetlock and joints below. Its principal use is as 

 a mechanical brace during standing and thus preserves 

 the balance; these two muscles form the hamstring. 



Flexion of this important joint is performed by power- 

 ful muscles (flexor metatarsi, extensor pedis and peron- 

 eus). The peroneus originates on the fibula, joins the 

 extensor pedis below the hock, and is of interest because 

 of the radical operation performed on it with the idea of 

 curing stringhalt ; it is really an accessory (helper) 

 muscle to the extensor pedis. The flexor metatarsi orig- 

 inates at the lower end of the thigh bone and terminates 

 at the lower portion of the hock by four insertions, one 

 of which is prolonged over the site of bone spavin, and 

 .in surgical work for the relief of such a condition is often 

 severed. The extensor pedis originates on the side of 

 the lower end of the thigh bone and is attached to the 

 three bones below the fetlock, consequently the joints 

 below the hock are extended by this muscle. An 

 acquaintance with the origins, insertions and actions of 

 the limb muscles is of especial value as an aid to detect 

 and locate lameness. The apparatus for performing 

 movements in animals is, as is seen, composed of bones, 

 ligaments and muscles, which are brought into a more 

 or less intimate relation, we might term it frictional 

 relation. Nature has made provision to reduce the fric- 

 tion and its consequences to a minimum, by what is 



