THE FEMUR \)\) 



really belongs to the abdomen, but is called the false or upper 

 pelvis. The pelvic outlet presents three large prominences, 

 the coccyx and the tuberosities of the ischia. Beneath the 

 symphysis and between the puboischiatic rami is the subpubic 

 arch; behind the ischial tuberosities are the sacrosciatic notches. 



Position of the Pelvis. In the erect attitude, with the 

 heels together and toes turned out, the plane of the brim forms 

 an angle of 60 degrees with the horizontal, that of the outlet 

 16 degrees. 'The base of the sacrum is about 3J inches above 

 the upper margin of the symphysis, and the tip of the coccyx 

 about \ inch above the apex of the subpubic arch. The sacrum 

 looks down and forward, and is the inverted keystone of an 

 arch, as its pelvic surface is broader than the dorsal; it is held 

 in place chiefly by ligaments and by a slight bony projection 

 into the iliac articular surface. 



Differences in the Pelvis According to Sex. In the female 

 the bones are more slender and the muscular impressions less 

 marked; the height is less, breadth and capacity greater; but 

 the false pelvis is relatively narrower than in the male. The 

 sacrum is wider and flatter, less prominent; the subpubic arch 

 is wider, about 90 degrees (male is 75 degrees); and the space 

 between the ischial tuberosities is greater. The thyroid fora- 

 men is broader and more triangular in the female, nearly oval 

 in the male. 



The sacrum and coccyx have been described as the false 

 vertebrae (page 28). 



THE BONE OF THE THIGH, 



The Femur 



The femur (thigh bone) is the largest, longest, and strongest 

 bone of the skeleton. In the erect position it inclines inward 

 and slightly backward. It is divisible into a superior extremity, 

 including head, neck, and two trochanters; shaft; and inferior 

 extremity, expanded into external and internal condyles and 

 epicondyles. 



The neck extends upward, inward, and slightly forward, 

 being set upon the shaft at an angle of 125 degrees. It 

 is compressed from before backward, is broad at its base, 



