124 LECTURE III. 



hands swing in the same direction, and 

 then the weight of the arm drags forward 

 the shoulder joints. In weakly children 

 whose bones are deficient in firmness, the 

 collar bones yielding under these circum- 

 stances, become convex in front, and the 

 bulky sternal extremities are in some de- 

 gree dislodged from their cartilaginous 

 beds. The blade bone is also drawn for- 

 wards on the convex ribs, so that the back 

 part projects beneath the skin. The weight 

 of the shoulders and liead now bears, in 

 some degree, upon the walls of the chest, 

 being transmitted by them to the vertebral 

 column, by which means they also become 

 deformed. 



So commonly do these causes operate in 

 the manner I have mentioned, that we 

 rarely see exactly such a collar bone as I 

 have endeavoured to describe ; they must 

 have been very healthy when young, who 

 have such collar bones as are represented 

 in the Grecian statues. To prevent the 

 deformities incident to the causes I have 

 mentioned, parents are accustomed to brace 



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