Academy of Sciences] 

 No. 3] 



MEASUREMENTS 



Arm Span 



27 



The arm span, or arm spread, is the distance from tip to tip of the longest fingers in maximum 

 extension of the arms. 22 It gives the length of the arms, which would be difficult to measure 

 separately, plus the breadth of the thorax at the shoulders. The average excess of the arm spread 

 over stature in 142 of the academicians was 4.2 centimeters, with considerable individual dif- 

 ferences. The crude data, contrasted with those on the old Americans at large (laboratory 

 series) are as follows: 



Table 24. — Arm spread 



The main value of the measurement lies, however, in its relation to stature. In modern 

 white man this relation averages near 104 (101-108). 23 In highly civilized groups it tends to 

 be less, in primitive peoples more than the general average. It presents interesting racial, sex, 

 and individual variations. 



In some of the more aged academicians this measurement was impracticable clue to changes 

 in the muscles and joints, but in a large majority conditions were fairly normal. The results 

 were as follows: 



Table 25. — Arm spread in percentage of stature 



Members of the Academy 



Old Americans 



Not old Americans 



Old Americans 



at large 



(laboratory series) 



Subjects 



Mean age, years 



Average 



Minimum 



Maximum 



Range of variation in percentage of the average 



CV. 



96 



58.8 



102. 19 ±0. 18 



96. 1 



108.2 



11. 84 



2. 64 + 0. 13 



2. 58 ±0. 12 



46 



61 



101. 78 ±0. 23 



98. 3 



106. 5 



8.05 



2. 28 ±0. 16 



2. 24 ±0. 16 



245 



37.2 



102. 6 



93 



110.9 



17. 43 



DISTRIBUTION 



Old Americans (97) 



Not old Americans (46) . 



1.1-96.9 



Percent 



1.0 

 2.2 



97-98.9 



Percent 



6.2 



8.7 



99-100.9 



Percent 



23. 7 

 26. 1 



101-102.9 



Percent 

 32.0 

 30. 4 



103-104.9 



Percent 

 21. 6 

 26. 1 



105-100.9 



Percent 



11. 3 



6. 5 



Percent 

 3. 1 



ARM SPREAD VERSUS STATURE AND AGE IN MEMBERS OF THE ACADEMY 



Members of the Academy 



Old Americans 



Not old Americans 



Subjects to 60 years of age, inclusive. 

 Average 



CV 



Over 60 years of age- 

 Average 



CV. 



58 



102. 17 + 0.25 



2. 78±0. 17 



2. 72±0. 17 



38 



102. 21+0. 26 



2. 39 + 0. 18 



2. 34 ±0. 18 



21 



102. 57 + 0. 33 



2. 24 + 0. 23 



2. 18 + 0. 23 



25 



12 + 0.29 



12 + 0. 20 



101. 

 2. 



2. 10 ±0. 20 



" The subject stands facing the observer, one finger touching a raised upright, arms held horizontal (at right angles to the body) , and subject direc- 

 ted to stretch to the maximum, while the thumbnail of the right hand of the observer is applied to the medius of the left or free hand of the subject, 

 is pushed by this as the subject stretches and remains when the farthest point is reached to mark the measurement. Two trials. 

 13 See the Old Americans, p. 126 et sen.. 



