SUPERFICIAL EXAMINATION 5 



peroneus muscle. In some animals this nerve may also be felt beneath 

 the skin and fascia. It takes a direction across the superficial aspect of 

 the muscle downwards and forwards, which approaches nearer the vertical 

 than that taken by the anterior tibial nerve. A large branch is given off 

 by this nerve for the supply of the peroneus muscle, and the nerve, much 

 reduced in size, continues its downward course along the line of the 

 apposition of this muscle with the extensor pedis. During this part 

 of its course, however, the nerve is more deeply seated, is wedged in 

 between the two muscles, and cannot be felt in an examination such as 

 we are now making. 



The depression just mentioned is of great importance, since it is 

 the seat of the operation of anterior tibial neurectomy. 



The belly of the extensor pedis will be found to be succeeded by 

 a tendon which passes beneath one of the annular bands at the inferior 

 extremity of the tibia, and plays over the front of the hock slightly 

 to the outer side of the middle line. Its subsequent course will be 

 traced later, as also will the tendon of the peroneus, which runs in a 

 vertical direction and plays through a groove on the outer side of the 

 external malleolus of the tibia. 



The back of the thigh is very fleshy, owing to the enormous 

 bulk of the hamstring muscles, which extend to a much lower level 

 than in man, so that in the horse the back of the stifie is well 

 protected, and the posterior common ligament of the joint is deeply 

 seated. The muscles of the hamstring also clothe and protect the great 

 sciatic nerve with its accompanying vessels. 



The inner aspect of the thigh will be found to be very fiat, and 

 the bone is here also clothed by muscles which are the adductors of 

 the limb. Those which form the superficial layer, and are subcutaneous, 

 are the sartorius anteriorly and the gracilis posteriorly. The gracilis 

 occupies about four-fifths of the area described, and its surface is quite 

 flat, whilst the skin covering the sartorius is slightly raised, since the 

 muscle forms an elevation which runs downwards and backwards. 



