﻿IX, B, 6 



Acosta-Sison: Pelvimetry and Cephalometry 



495 



Table II. — Comparison of the cephalic measurements in American and 



Filipino infants. 



Measurement. 



Ameri- 

 can. 707 



cases 

 (Rierss). 



Filipino. 

 117 cases. 



Dififer- 

 ence. 



Occipitomental. - - 



Occipitofrontal 



Suboccipitobregrmatic 



Biparietal 



Bitemporal 



Occipitomental circumference 



Occipitofrontal circumference - 



Suboccipitobre^matic circumference- 



cm. 



13.33 



11.707 



9.70 



9.25 



8.00 



32.17 



em. 



12.11 



10.96 



9.28 



8.63 



6.829 



36.56 



32.04 



30.26 



em. 



1.22 



0.747 



0.42 



0.62 



1.171 



1.91 



Table I shows that the diameters of the Filipino pelvis are 

 shorter than those of the American or European pelvis. On 

 studying this table closely, one finds that the relation of one 

 diameter to another is altered in such a way that the propor- 

 tion of the crests with the spines in the Filipino pelvis is much 

 smaller than the proportion of the same diameters in the Euro- 

 pean or American pelvis and that the proportion of the diagonal 

 conjugate with the other diameters in the Filipino is very slightly 

 larger than in the American. This would seem to show that the 

 Filipino pelvis is narrower and relatively slightly deeper than 

 the American pelvis. This diminution may be explained by the 

 small stature of the Filipinas. However, the most striking dif- 

 ference is that, although the Filipino pelvis is smaller than the 

 American pelvis, the transverse diameter of the pelvic outlet 

 is the same as that of the Caucasian race. 



To find an explanation for this peculiarity would take us back 

 to the mechanical theory of the production of the shape of the 

 human pelvis. It is well known that the pelvis of the child alters 

 in shape in proportion to mechanical influences such as that of 

 osteomalacia. It is also an established fact that the sitting 

 posture flares out the ischial tuberosities, and this is proved in 

 some cases of osteomalacia where the patient has maintained 

 the sitting posture for a long time. In applying this theory in 

 our cases, it must be remembered that the Filipino woman from 

 her childhood has habitually accustomed herself to the squatting 

 position or to sitting on the hard floor with the knees dravm up, 

 and her occupation is such that she is obliged to be in this position 

 for nearly the whole day. Whether she sews, cooks, washes, 

 or sells in the market, she nearly always assumes this position. 



