. The development of the human body : a manual of human embryology. Embryology; Embryo, Non-Mammalian. POST-NATAL DEVELOPMENT 485 It is a well-known fact that the new-born child habitually holds the feet with the soles directed toward one another, a position only reached in the adult with some difficulty, and associated with this supination or inversion there is a pronounced extension of the foot (i. e., flexion upon the leg as usually understood; see p. 102), it being difficult to flex the child's foot beyond a line at right angles with the axis of the leg. These conditions are due apparently
. The development of the human body : a manual of human embryology. Embryology; Embryo, Non-Mammalian. POST-NATAL DEVELOPMENT 485 It is a well-known fact that the new-born child habitually holds the feet with the soles directed toward one another, a position only reached in the adult with some difficulty, and associated with this supination or inversion there is a pronounced extension of the foot (i. e., flexion upon the leg as usually understood; see p. 102), it being difficult to flex the child's foot beyond a line at right angles with the axis of the leg. These conditions are due apparently to the ex- tensor and tibialis muscles being relatively shorter and the opposing muscles relatively longer than in the adult, and with the elongation or shortening, as the case may be, of the muscles on the assumption. Fig. 2S5.—Longitudinal Sections of the Head of the Femur of (.4) New-born Child and (B) a Later Stage of Development. ep, Epiphysial center for the head; h, head; /, trochanter.—(Henke.) of the erect position, the bones in the neighborhood of the ankle- joint come into new relations to one another, the result being a modi- fication of the form of the articular surfaces, especially of the talus (astragalus). In the child the articular cartilage of the trochlear surface of this bone is continued onward to a considerable extent upon the neck of the bone, which comes into contact with the tibia in the extreme extension possible in the child. In the adult, however, such extreme extension being impossible, the cartilage upon the neck gradually disappears. The supination in the child brings the talus. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original McMurrich, J. Playfair (James Playfair), 1859-1939. Philadelphia : P. Blakiston's son & co.
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Keywords: ., bookautho, bookcentury1900, bookdecade1910, booksubjectembryology
