THE SHOULDER-GIRDLE. 



237 



as will not incite the muscles to contraction, by a quick movement accomplishing the 

 object before the muscles are able to contract, or, finally, by overcoming the muscular 

 action by steady continuous traction. General anaesthesia is the surest way of obvi- 

 ating muscular contraction. 



The question of muscular contraction having been solved by one or more of these 

 expedients the actual replacement is to be accomplished by dragging or pushing the 

 head back over the route it took in coming out. The opening in the capsule is 

 below and anterior, therefore the arm is to be strongly abducted, and traction made 

 upward and backward. This drags the head upward and backward over the rim of 

 the glenoid cavity into its socket. If it does not enter readily it is because of tension 



Coracoid process 



Acromion process 



Long head of biceps 

 Supraspinatus 



Infraspinatus 

 Teres minor 



Deltoid detached 

 from the clavicle 

 and turned back 



Long head 

 of triceps 



Coracobrachialis 



and short head 



of biceps 



Pectoralis major 



Pectoralis minor 



Displaced head 

 of humerus 



Subscapularis 



FIG. 249. Subcoracoid dislocation of the shoulder. Dissection showing the relation of the muscles to the dis- 

 placed humerus. 



of the untorn part of the capsule; this is to be remedied by gently rotating the arm, 

 when the proper position will be revealed by the slipping of the head into place. Rota- 

 tion in either direction beyond the proper point narrows the tear in the capsule and 

 keeps the head from entering. Traction is necessary in order to replace the head of 

 the humerus on its pedestal or shoulder-girdle from which it has fallen onto the side 

 of the chest (see Figs. 248 and 250). 



If it is desired to tire the muscles out, the plan of Stimson is best. Place the 

 patient in a canvas hammock and allow the arm to hang downward through a hole 

 in the canvas. Fasten a ten-pound weight to the wrist and inside of six minutes the 



