THE LIMBS OF THE HORSE 



69 



freedom. Adduction and abduction are restricted by the sub- 

 scapular and infraspinous insertions, and rotation and circumduction 

 are limited by the other muscular attachments about the joint. 



The elboav joint (articulatio cubiti). — The term "elbow joint," 

 strictly speaking, includes three joints, namely, the liumero-radial 



Lig. coUaterale laterale. 



Radius. . 



-Humerus. 



.M. bicepslbrachii. 



- M. brachialis. 



.Lig. coUaterale mediale 

 (long). 



Fig. 48. — Anterior Aspect of the Elbow Joint. 

 Tlie red line indicates the line of attachment of the synovial lining of the joint capsule. 



articulation (articulatio humeroradialis), the humero-ulnar articula- 

 tion (articulatio humeroulnaris), and the proximal radio-ulnar articula- 

 tion (articulatio radioulnaris proximalis). In describing the joint of the 

 horse it is convenient to include the union between the shafts of the 

 radius and ulna as well. 



The opposed bony surfaces of the humerus and the radius and ulna 

 are so moulded and adapted to each other as to coXvince the dissector 

 that movement in the joint can take place in one plane only. The 

 presence of strong collateral ligaments contributes to the limitation 

 of movement to flexion and extension. 



The joint capsule (capsula articularis), attached to the articular 

 margins of all thve^]^fff^fj ^ f}ffgf;^^ff(g>n the extensor (anterior) 



