. The science and art of midwifery. pid locomotion, is, in a specialdegree, adapted to render possiblethe birth of the child. A femalepelvis approximating in type tothat of the male gives rise to avariety of dystocia of a very formi-dable character. Differences between the Infan-tile and Adult Pelvis.—In the in-fantile pelvis the promontory occu-pies a relatively higher positionabove the upper border of the sym-physis ; the last lumbar and twoupper sacral vertebrae possess amoderate convexity—i. e., thepromontory does not project for-ward, as in the adult; the sacrum,after running a straight c
. The science and art of midwifery. pid locomotion, is, in a specialdegree, adapted to render possiblethe birth of the child. A femalepelvis approximating in type tothat of the male gives rise to avariety of dystocia of a very formi-dable character. Differences between the Infan-tile and Adult Pelvis.—In the in-fantile pelvis the promontory occu-pies a relatively higher positionabove the upper border of the sym-physis ; the last lumbar and twoupper sacral vertebrae possess amoderate convexity—i. e., thepromontory does not project for-ward, as in the adult; the sacrum,after running a straight course, be-gins to curve forward first at thefourth vertebra ; the alse are slight-ly developed; the inclination ofthe ilia more nearly approaches theperpendicular ; the S-shaped curveof the crests is barely indicated,there being but slight differencein the distances between the crests and anterior superior spines ; the conjugate diameter in proportion tothe transverse is increased ; the side-walls converge toward the outlet ;11. Fig. 100. Vertical section of a female infan-tile pelvis. ( 162 LABOR. the pubic arch is formed at an acute angle ; and the distance betweenthe spines of the ischia is greater than the transverse diameter of theoutlet. Distinctions pertaining to sex are but slightly accentuated. Inthe female, the sacrum, owing to the smaller size of the vertebra?, isnarrower than in the male ; the side-walls are higher; the symphysislower ; the iliac incline approaches more nearly a vertical line ; thepubic arch is less acute ; and the transverse diameter is increased. The most important agent in effecting the changes which char-acterize the adult pelvis is unquestionably the weight of the to the wedge-shape of the sacrum, and the shelf-like ledgewhich projects from the lower surface of the iliac articulation, no dis-placement can take place in the direction of the long axis of the au-
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Keywords: ., bookcentury1800, bookdecade1890, bookidsci, booksubjectobstetrics
