CHAPTER VI 



THE TENDONS, LIGAMENTS, TENDON SHEATHS, 



AND BURS^ 



THE TENDON OF THE INFRASPINATUS MUSCLE AND 



ITS BURSA 



This is a short powerful tendon which runs downwards and forwards. 

 It divides into two portions, the inner of which is inserted into the 

 inner aspect of the convexity or posterior division of the external 

 tuberosity of the humerus, whilst the outer division plays over the outer 

 surface of the convexity, and is inserted into the upper end of the 

 deltoid ridge. Between the outer division and the surface of the 

 convexity there is placed a small synovial bursa. 



Attention has already been drawn to the exposed position of the 

 bursa and the tendon, and their liability to injury by the animal falling 

 on its broadside. In addition, since the infraspinatus muscle, besides 

 being a flexor of the shoulder, is also a powerful abductor of the limb, in 

 animals with narrow chests, particularly those which have to do fast 

 work, we find considerable strain thrown upon this tendon in the natural 

 endeavour of the animal to bring about as great a degree of abduction 

 as possible, to avoid injuries to the limbs, such as speedy-cutting, &c., 

 during progression. The tension thus thrown upon the tendon in 

 animals of such conformation is not infrequently too great, and the 

 tendon, together with the underlying bursa, becomes inflamed. 



In cases of inflammation the animal is lame, and during progression 



