164 SURGICAL APPLIED ANATOMY. [Chap. xi. 



an index to the position of the upper end of the 

 bone. 



In thin subjects the outline and borders of the 

 scapula can be more or less distinctly made out, but 

 in fat and muscular subjects all parts of the bone, 

 except the spine and acromion, are difficult of access 

 in the ordinary positions of the limb. To bring out 

 the superior angle and vertebral border of the bone, 

 the hand of the subject should be carried as far as pos- 

 sible over the opposite shoulder. To bring out the 

 inferior angle and axillary border, the fore-arm should 

 be placed behind the back. The angle formed at 

 the point of junction of the spine of the scapula 

 and the acromion, is the best point from which to 

 take measurement of the arm, the tape being carried 

 down to the external condyle of the humerus. 



When the arm hangs from the side with the palm 

 of the hand directed forwards, the acromion, external 

 condyle, and styloid process of the radius, all lie in the 

 same line. The groove between the pectoralis major 

 arid deltoid muscles is usually to be made out. In it 

 run the cephalic vein and a large branch of the ac. romio- 

 thoracic artery. Near the groove, and a little below 

 the clavicle, the coracoid process may be felt. The 

 process, however, does not actually present in the 

 interval between the two muscles, but is covered by the 

 innermost fibres of the deltoid. The position of the 

 coraco-acromial ligament may be defined, and a knife, 

 thrust through the middle of it, should strike the 

 biceps tendon and open the shoulder joint. 



When the arm hangs at the side with the palm 

 forwards, the bicipital groove may possibly be defined. 

 It looks directly forwards. 



Just below the clavicle is a depression, the sub- 

 clavicular fossa, which varies considerably in depth 

 in different subjects. It is obliterated in subcoracoid 

 dislocations of the hurnerus, in fractures of the clavicle 



