Page:Popular Science Monthly Volume 22.djvu/339

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of the limbs in girls at puberty, which I have described; and what is remarkable, and not easily explained, the deformity generally occurs only in one foot, or is greater in one than in the other. In this way, however, the legs become of unequal length, and we have obliquity of

PSM V22 D339 Pelvic size variations between age and gender.jpg
The diagram shows the relation of the brim of the pelvis in the child, at puberty, and in the adult female, from measurements of pelves in the museum of the Royal College of Surgeons. The want of parallelism of the two inner pelvic curves shows that in the change from the infantile to the female type evolution takes place chiefly behind, and that the legs must be rotated forward and inward. The dimensions areā€”Child: breadth, 83 mm.; length, 73; index, 114. Young female: breadth, 112 mm.; length, 85; index, 132. Adult female: breadth, 143 mm.; length, 108; index, 132. The indices of the young female and the adult are the same, but the bones of the former are not united together.

the pelvis, and consequently lateral curvature of the spine to correct the balance of the body, and bring the head and shoulders into the line of the center of gravity. Flat-foot also produces, or exaggerates, the natural disposition to knock-knee in girls, which, in its turn, adds to the inequality in the length of the two legs. Some observations recently made in America show that even in adults of both sexes the two legs are rarely of equal length, and there must be, therefore, slight lateral curvature in all persons, and it is probable that these natural curves become exaggerated, as in the development of round shoulder the large antero-posterior curves of the spine are exaggerated. It is to the wasting or non-development of the fleshy parts of the deep flexors of the toes or foot that Europeans owe the small ankle and the comparatively large calf of which they are so proud as distinguishing them from the lower races. It is a distinction, however, which is more than counterbalanced by the ugliness and inconvenience of flat-foot, to which it frequently gives rise. The ingenuity of an Edison could not devise a machine so favorable to the production of flat-foot as the tight-fitting, high-heeled, long-topped boot at present worn by girls. Not only does the rigidity of the front part cramp the action of the muscles, but the high heels place the foot at such an angle with the leg that the tendons are of least use in supporting the ankle-joint, and the long tops hamper the development of the muscles in the remainder of their course. The high heels, moreover, push the center of gravity forward on the arch of the foot, and by propping up the heel gives greater lev-