2 THE SUPERIOR EXTREMITY 



be compressed downwards, backwards, and medially against 

 the second rib. 



The lateral border of the acromial end of the clavicle is 

 marked by a weak ridge directed from before backwards, i 

 inches medial to the lateral border of the acromion. When 

 the acromio-clavicular ligaments are lax, it is possible to insinuate 

 the finger-nail between the articular surfaces of the joint. An 

 adventitious subcutaneous bursa is occasionally met with over 

 this region in those accustomed to carrying heavy weights 

 upon the shoulder. 



The coracoid process of the scapula is not situated in the 

 superficial infra-clavicular triangle, but lies under cover of the 

 anterior border of the deltoid. It can be felt on direct backward 

 pressure one inch below the clavicle lateral to the junction of 

 its middle and lateral thirds. 



The apex of the acromion is placed one quarter to half an inch 

 in front of the acromio-clavicular joint. Its lateral border 

 can be traced backwards for about two inches, till it joins the 

 inferior border of the scapular spine, which meets it at the 

 sharp acromial angle. When the upper arm is measured in 

 suspected fracture of the humerus, the acromial angle is utilised 

 instead of the acromion apex, the latter being more obscured 

 by the deltoid. The subcutaneous upper surface of the acromion 

 can be readily examined when the arm is supported in the 

 abducted position, although the medial border is overlapped 

 by the trapezius and the lateral by the deltoid. 



The spine of the scapula can be traced medially and downwards 

 to its flattened root opposite the third thoracic spine. 



The superior border and the medial (superior) angle of the 

 scapula are on a level with the second rib, but cannot be palpated 

 easily, since they are under cover of the trapezius and the 

 supra-spinatus. They can be examined if the upper fibres of 

 the trapezius are relaxed by carrying the patient's arm as far 

 as possible over the opposite shoulder. 



The lower three-fourths of the vertebral border, the inferior 

 angle, which lies over the seventh rib or seventh intercostal 

 space, and the lower part of the axillary border, can all be 

 palpated, if the patient's forearm is carried behind his back so as 

 to relax the trapezius, the rhomboids, and the latissimus dorsi. 



The anterior fold of the axilla is formed by the lower border 

 of the pectoralis major, which, at its medial attachment, follows 

 the line of the fifth rib. A line, drawn from the lower margin 



