388 



one limb of a pair of calipers upon the upper surface of the clavicle, 

 so as to touch the bone at the sternal and the acromial ends, and 

 adjusting the other limb to the horizontal. 



It must be noted that this is an oblique measurement and does 

 not represent the true vertical elevation of the clavicle but is the 

 clavicular angle as measured clinically in the living subject. This 

 angle is indicated in Fig. II. The result of the investigation is tabu- 

 lated in the Appendix. (Column A.) 



Among the 75 persons examined, there were: — 



21 men of ages ranging from 23 to 62. 

 14 women „ ,, „ „18 to 63. 



22 boys „ „ „ „ 3 to 13. 

 18 girls „ „ „ ,, 3 to 13. 



The result shows that very great individual variation occurs in 

 the angle between the clavicle and the horizontal. 



Taking general averages it is found that in the cases examined 

 the following gives a representative table: — 



Men average angle = 290. 

 Women „ „ = 26o. 



Boys „ „ = 26«. 



Girls „ „ = 25.4". 



In taking the measurements it was frequently found that the 

 clavicular angle was less on the right side than on the left. This 

 probably results from the greater use of the right arm. For in persons 

 who use one arm considerably more than the other it is conceivable 

 that the corresponding shoulder would tend to descend more than 

 the opposite shoulder which undergoes less exercise. The point is 

 of interest in view of the fact that the symptom complex of cervical 

 rib occurs more usually on the right than on the left side. I have 

 seen two cases where the symptoms commenced on the left side in 

 left-handed persons. In instances where the clavicular angles on the 

 two sides were unequal, the average of the two was taken. 



In considering the results of these measurements the first im- 

 pression received was that possibly the greater muscular development 

 in the adult male prevented the shoulder from descending to the 

 same extent as in the adult female, whose muscular development is 

 less marked than in the male. But it is obvious that if such be the 

 case, the position of the shoulder in the child should be comparatively 



