Sex efficiency through exercises : special physical culture for women / by Th. H. van de Velde ; [photos, by E. Steinemann].

final phase in this particular technique is the lifting of the woman's legs, simultaneously with the greatest possible backward curve of her lumbar region, which brings pelvic inclination to its minimum. It is possible to express the difference in pelvic inclination between the first and the final attitudes by means of numbers. The median line of the pelvic floor—which is drawn from the point of junction between the sacrum and the lumbar vertebrae at the rear, to the upper rim of the symphysis pubis in front—is termed the conjugata vera. In the extended horizontal attitude the conjugata vera forms an angle of 145 degrees with a second imaginary line along the anterior surface of the lumbar vertebrae. If the woman draws in her loins (and protrudes her coccyx and gluteal region) this angle is increased. But in pronounced flexion it only amounts to 115 degrees. In my monograph on " Fertility and Sterility " these two attitudes and angles are shown in Figs. 3 and 4 respectively of Plate VIII., for which I am indebted to Bumm's great work on " Gynaecological Surgery."(25) They are reproduced here as Plates VI. and VII. The differences in the vaginal axis deserve careful attention. The Exercise No. 19 in our series (Film 12, Figs. 12 and 13) gives some idea of the attitudes and anatomical conditions involved. If we consider the second main coital position—the Averse or a Tergo—in which the face and abdomen of the man are turned towards the woman's back, we shall find that it is also possible to modify pelvic inclination with happy results. But, in coitus a tergo, there is generally no phallic friction of the clitoris—which is situated on the anterior rim of the pubic floor, whereas the man approaches from behind. The exception to this rule among the averse attitudes is the extreme form of the ninth group *—especially if the loins * Described as follows in " Ideal Marriage," p. 233: " The woman kneels while her body from trunk to thighs is inclined at a more or less acute angle. Her body can be stretched horizontally, supporting itself on hands and arms or on a couch or chair of appropriate height. A third variation is also possible, the woman's body can slope downwards from pelvis to head with shoulders and elbows resting on a low couch or chair (the famous knee-elbow posture used in gynecology), and form an angle to the upright thighs or legs. There is no substantial difference between the variations mentioned above and an attitude in which the woman stands on her feet and bends her body as far forward as possible from the hips."