MUSCLES or THE RIGHT SUPERIOR LIMB 53 



These muscles can function in such a fashion as to justify their 

 being placed in first one and then in the other of functional 

 groups I and 2 and groups A and C. The biceps brachii m. 

 (20) is a good example of such a muscle, and there are numerous 

 other such examples. 



C. MUSCLES OF THE SHOULDER JOINT 



(Nos. 12-19; Figs. 10-12, 18) 



12. Clavodeltoid (cleidohumeralis, clavobrachialis) m.: 

 Clavicle and cleidohumeral ligament mainly; to craniolateral 

 border of middle two-thirds of humerus. Draws arm craniad. 

 This is the continuation of the basioclavicularis m. (4). 



13. Acromiodeltoid m.: Acromion and metacromial process; 

 to deltoid ridge of humerus. Draws humerus caudad and 

 laterad. 



14. Supraspinatus m. : Most of spine and body surfaces of the 

 supraspinous fossa of scapula, which it fills completely and over- 

 laps the cranial border of the scapula; to greater tuberosity of 

 humerus. Draws humerus craniad. Method: Since the distal 

 end of the pectoscapularis m. (8^) completely envelops the 

 supraspinatus the pectoscapularis will have to be probed and 

 transected about at its middle to expose the supraspinatus, 

 which may be explored by inserting a small probe or stout 

 dissecting needle under it at the cranial margin of the acromion. 

 It need not be transected. 



15. Infraspinatus m.: Spine and body surfaces of infra- 

 spinous fossa; to greater tuberosity of humerus. Rotates 

 humerus. Probe, but do not transect. 



16. Teres major m.: Vertebral third of axillary border of 

 scapula; to craniomedial surface of humerus, distad of greater 

 tuberosity, with tendon of latissimus dorsi m. (2). Draws 

 humerus caudad and rotates it mediad. 



17. Teres minor m.: Axillary border of scapula and sub- 

 scapularis m. (18); to humerus with t. major. This muscle 

 lies between the teres major m. (16) and the infraspinatus m. 



