

THE UPPER EXTREMITY. 127 



The movements of which the humerus is capable in 

 the glenoid cavity are very varied, and, with a view to 

 studying the action of the muscles in dislocation and 

 fracture of this bone, and in their diagnosis, may be 

 classified as follows : The humerus is raised by the del- 

 toid, supra-spinatus, long head of biceps, and coraco- 

 brachialis ; depressed by the pectoralis major, latissimus 

 dorsi, teres major, and subsc'apularis ; brought forward 

 by the pectoralis major, anterior fibres of deltoid, coraco- 



FlG. 20. 



Diagrammatic section through right shoulder-joint, showing structures in con- 

 tact with it. 1. Clavicle. 2. Acromion. 3. Supra-spinatus. 4. Trapezius. 5. 

 Infra-spinatus. 6. Teres minor. 7. Teres major. 8. Latissimus dorsi. 9. Coraco- 

 brachialis and short head of biceps. 10. Tendon of subscapularis blended with 

 the capsular ligament. 11. Pectoralis major. 12. Deltoid. 13. Axillary vessels 

 and nerves. 



brachialis, and short head of biceps ; drawn backwards 

 by the latissimus dorsi, teres major, long head of triceps, 

 posterior fibres of deltoid, supra-spinatus, and teres 

 minor; rotated inwards by subscapularis, teres major, 

 latissimus dorsi, pectoralis major, and anterior fibres of 

 deltoid ; rotated outwards by the infra-spinatus, teres 

 minor, coraco-brachialis, and posterior fibres of deltoid. 



