THE SHOULDER. 



29 



joint in the body, owing to the smallness of the scapular sur- 

 face, compared with the globular humeral surface, on which 



Fig. 10. SHOULDER, a, clavicle; b, acrornion; c, coracoid process ; 

 d, glenoid fossa of the scapula; e, humerus. 



it moves, and the looseness of the liga- 



mentous capsule which unites the two 



bones; but the coracoid and acromial 



processes overhang the joint sufficiently 



to add greatly to its strength; for it 



is against them that the humerus is in 



great measure pushed in all positions in 



which great pressure is made against it.- 

 In the forearm there are two bones 



named radius and ulna. The ulna, the 



inner of the two, is strong above and 



slender below, and admits of no move- 

 ment save in a hinge fashion on the 



humerus, with which it articulates by 



means of a cavity which looks forwards, 



and is bounded below by the coronoid 



process, above by the olecranon or pro- 

 minence of the elbow. The radius, Fig. 11. 



Fig. 11. RADIUS AND ULNA, a, olecranon process of ulna; 5, 

 coronoid process; c, orbicular ligament, embracing the head 

 of the radius ; d, triangular ligament, uniting the radius to 

 the styloid process of the ulna. 



