Chapter XLVII: Strength of the Femur on the Two Sides of the Body

MEAN DIAMETER AT THE MIDDLE OF THE SHAFT
---------+------+------+--------
| |United|United
|Munsee|States|States
| |whites|negroes
---------+------+------+--------
Male: |_cm._ | _cm._| _cm._
Right| 2.73 | 2.89 | 2.91
Left | 2.75 | 2.91 | 2.91
Female: | | |
Right| 2.46 | 2.74 | 2.60
Left | 2.43 | 2.64 | 2.60
---------+------+------+-------

Taking the antero-posterior and lateral diameters at the middle of the shaft separately, we find several more interesting points. The antero-posterior diameter in the Munsee (and the same is true of the United States whites and United States negroes, as will be seen by the following table) is practically equivalent in the right and left femora in the males; but except in the whites it is perceptibly smaller on the left side in the females of all groups. On the other hand, the lateral diameter, excepting in the probably too small male negro series, is invariably larger on the left than on the right side in both males and females. Thus it may be said that the left femur is almost invariably slightly broader on the average than the right, and this especially in the females of probably all racial groups.

These interesting conditions are most clearly shown by the shaft index

diameter lateral × 100
—————-———————
diameter antero-posterior

which in both sexes and in all the racial subdivisions is higher on the left side.

The index in the Munsee femora is noteworthy in another respect: It is decidedly smaller in both sexes of this group than it is in the American negro and especially in the United States whites. Judging from data on other Indians in the writer’s possession, it seems very probable that the characteristic shown by the Munsee in this regard is common to Indians in general. As may be seen by reference to the figures in the following table, the low shaft index in the Munsee is due entirely to smaller breadth; the Munsee femur is relatively narrower than that of both whites and negroes.