510 HEIGHT AND WEIGHT IN RELATION TO BUILD 



and in table K. Quetelet's data (table E) give values from 1 to 2 per cent of the 

 stature lower. 



Length of lower extremity. Compared with the length measured from the tro- 

 chanter, the difference in the length of the lower extremity measured from various 

 other levels amounts approximately to the following percentages of the stature : 



From crest, S to 10 per cent of stature, greater. 



From iliac spine, 4 to 5 per cent of stature, greater. (Greater after puberty than before. Greater in girls than 



in boys.) 



From pubis, 1 to 2 per cent of stature less. (Greater before than after puberty.) 



From stature minus sitting-height 4 to 5 per cent of stature less. (Greater before than after puberty.) 

 From sole to crotch 3 to 4 per cent of the stature less. 



According to the data of Weissenberg (table D) the difference in relative length 

 of the lower extremities measured from the trochanter and measured by subtracting 

 sitting-height from stature is greatest in the infant, decreases rapidly during the 

 first three years after birth, and then more slowly until the tenth to twelfth year. 

 In males it now once more begins to increase and this increase continues at first 

 rapidly, then slowly to the fiftieth year. At 15 in males, during a period of rapid 

 growth in length, it does, however, show a temporary decrease. In late adolescence 

 it increases. In old age it decreases. In females it increases to the seventeenth 

 year and then remains nearly constant until old age, when it decreases. 



The decrease in difference in the relative length of the two measurements of the 

 lower extremities following infancy is due mainly to change in shape of the infantile 

 femur and pelvis and in the form of the lumbo-sacral curve. There is during this 

 period a relative increase in the length of the lumbar region of the spinal column 

 (Bardeen 1905). The increase during adolescence and in the adult male is probably 

 to be ascribed partly to skeletal changes, partly to the accumulation of fat on the 

 buttocks. To this cause may also, in part at least, be ascribed the differences 

 between males and females, the female in youth and maturity showing as a rule a 

 greater difference between the two measurements under consideration than the 

 male. Weissenberg's data show that the relative length of the lower extremities 

 measured from the trochanter is about the same in boys and girls of the same 

 stature up to 48 inches height (9 years of age), but that after the tenth year the 

 lower extremities grow faster in relative length in boys than in girls, reaching a 

 maximum of 53.2 per cent of the stature at the fifteenth year (height 60.5 inches). 

 In girls the maximum relative length of the lower extremities (52 per cent of the 

 stature) is reached at the thirteenth or fourteenth year (height 57 to 59 inches). 

 After the period of maximum relative length in both sexes there is a decline in rela- 

 tive length of the lower extremities amounting to about 1 per cent of the stature. 



Height of knee-joint. Data on the height of the knee-joint are unsatisfactory. 

 Technical difficulties in locating the level of the joint cavity have led to considerable 

 variation in landmarks chosen and in results reported. Quetelet (table E) gives the 

 relative height of the patella as progressively increasing from 23 per cent of the 

 stature in infancy to 28.4 per cent in the adult male, 28 per cent in the adult female. 

 He fails to note here, as in many of his data on growth, the influence of puberty on 

 the growth-curve. In general his data give a somewhat higher curve for males than 

 that shown in chart I but about the same curve for females. The data on the 



