24 Anatomy Applied to Medicine and Surgery. 



latissimus dorsi, from the six lower dorsal, from all the 

 lumbar and sacral spinous processes, and from the crest 

 of the ilium and the three or four lower ribs ; into the bot- 

 tom of the bicipital groove of the humerus, draws this 

 bone, backwards, at the same time rotating it inwards. It 

 is the principal muscle brought into play in striking a 

 downward blow. 8. The teres major,, from the dorsal 

 surface of the inferior angle of the scapula; into the pos- 

 terior bicipital ridge, assists the latissimus dorsi in draw- 

 ing the humerus, downwards and backwards, and also in 

 rotating it inwards. When the arm is fixed, this muscle, 

 with the latissimus dorsi and pectoralis major, draws the 

 trunk forward. 9. The action of the pectoralis major will 

 be considered when dealing with the axilla. 10. The 

 subscapidaris, from the inner two-thirds of the subscapu- 

 lar fossa; into the lesser tuberosity of the 'humerus, pre- 

 vents displacement of the head of the bone forwards ; ro- 

 tates the head inwards, and, when the arm is raised, assists 

 in drawing it downwards. Lastly, the biceps, by two heads 

 one, the longer, from the supraglenoid tubercle above the 

 glenoid fossa, arches over the head of the humerus and 

 passes down the bicipital groove to unite with the other, 

 the shorter, which arises from the apex of the coracoid 

 process in company with the coraco-brachialis. This 

 union is, however, by means of a delicate areolar tissue, 

 only ( true union not occurring until about an inch above 

 the beginning of the tendon of insertion where the fibres 

 of the two heads interlace with one another) . The biceps 

 tendon, after giving off an expansion from its inner bor- 

 der to the fascia of the forearm, is inserted into the back 

 part of the bicipital tuberosity of the radius. The tendon 

 of origin of this muscle lies in the interior of the shoulder 

 joint, but is outside of the synovial membrane, just as the 

 round ligament of the liver is outside of the peritoneum, 



