' (jo) Histokr of the socivrr. 



Account of ia the (Uflocation downwards ; and in that to the fide, by turning 



"VV. Hamilior. , , ,- i ,■ i r- i r i 



the humerus towards tiie lule ot the Icapula oppolite to that on 

 which its head is lodged, the lateral mufcle is taken off the 

 llrctch it was put into by the diflocatlon. When thefe over- 

 ftretched niufclcs ai-e thus attended to, the reducflion becomes 

 more eafy to the lurgeon, and much lei's hazardous to the pa- 

 tient, as laceration is guarded againll. 



" After long and violent attempts to reduce the flioulder, 

 particularly with the mufcles on the ilretch, I have heard of the 

 bone becoming fo loofe, that when it had been at laft got into 

 its focket, it fell out again very readily. This I imagine muft 

 have been owing to the mufcles round the joint, and the ligament, 

 having been very completely torn, fo that the humerus had loft 

 its natural fupport. In the two modes of rediuRiion moft com- 

 monly made ufe of, the ftate of the mufcles is not enough at- 

 tended to. When the arm is at an acute angle with the fide, as 

 when we attempt to force in the bone with the heel in the ax- 

 illa, the fuperior mufcles are very much on the ftretch; and 

 when the patient is placed on a chair, and the arm forms a right 

 angle with the body, they are ftill not fufficiently relaxed to pre- 

 vent additional difficulty and danger ; and I muft agree with 

 Mr Thomson in thinking attempts in thefe diredlions often the 

 caufe of fucceeding bad confequences. Another advantage of re- 

 duction with the raifed arm is, that as foon as the humerus is 

 difengaged from the fcapula, the mufcles, that from the nature 

 of the diflocation were moft extended, contracling, pull it into 

 its focket. In other modes of reducflion, a confiderable force is 

 required to prefs the bone into its place, after the arm is fully 

 extended. When this force is great, the parts that lie over the 

 bone muft be bruifed, particularly if a hard body is ufed to ef- 

 fed: this purpofe. On this account the Ambe^ both of Freack 

 and Petit, appears to me a bad inftrument. It pulls out the 

 arm at right angles, and therefore it requires confiderable ac- 

 tion 



