SHOULDER LAMENESS. 255 



tlie animal to rise bodily from the ground. It must, however, 

 be always understood that uneasiness when these move- 

 ments are performed, or when the shoulder is pressed upon, 

 is of itself insufficient to determine the seat of lameness, as 

 many horses are fidgety, and will not bear such handling. 

 But if there be a drag in the gait, along with the other 

 signs, it may fairly be concluded that the case is one of 

 shoulder lameness. 



Sprain of the Flexor Bracliii. — This muscle contains a large 

 amount of tendinous fibres, and is entirely tendinous as it passes 

 over the bicipital groove in front of the superior extremity of 

 the humerus, over which it plays like a rope over a pulley, 

 becoming inserted finally into the inner head of the radius. 

 Both it and the groove are lined with fibro-cartilage, and 

 enclosed w^ithin a synovial sac. It extends from the sca- 

 pula to the head of the radius, and its function is to flex 

 the fore arm upon the shoulder, — an important function, ren- 

 dering the structures which perform it liable to injury and 

 disease. 



In sprain of the flexor brachii, the muscle, along nearly all 

 its course, will be found swollen and inflamed, standing out 

 prominently from the surrounding structures. This swelling, 

 along with that of the bursa in front of the shoulder, pain upon 

 pressure, and the gait peculiar to shoulder lameness, namely, a 

 difficulty in elevating the foot from the ground, are the diagnostic 

 symptoms. 



It might be supposed that disease of the bicipital groove 

 would, from contiguity of situation, be always accompanied by 

 disease of the shoulder-joint itself; but such is not the case, 

 as may be seen from an examination of Photo-lithograph, 

 Plate I., Fig. 5. In many cases, however, the joint becomes 

 affected. 



The result of sprain of the flexor brachii is inflammation of 

 the tendon and the structures of the bursa, which, if not arrested, 

 will run on to ulceration of the cartilage upon the tuberosities of 

 the humerus, to caries of the bone, degeneration and rupture 

 of the tendinous fibres, and finally to ossification of the whole 

 substance of the muscle and tendon. The reason why ossifi- 

 cation, and not atrophy, as in inflammation of other muscles, 

 must be looked for, is the fact that the flexor hrachii is mostly 



