THE LOWER EXTREMITY, POSTERIOR. 599 



THE LOWER EXTREMITY, Posterior. 



LANDMARKS. Figs. 76, 126. 



The landmarks as given on page 554 should be consulted. 



The crest of the ilium curves backward to terminate in 

 the posterior superior spinous process of the ilium. The 

 spines of the sacrum and the termination of the spinal 

 column in the coccyx are easily felt. 



The tuberosity of the ischium is an important reference 

 point to which the posterior part of Nelaton's line is carried. 



The difficulty in determining what is the most prominent 

 part of the tuberosity of the ischium is the difficulty be- 

 longing to all so-called anatomical "points," which are in 

 reality "broad surfaces." This difficulty of exactly locat- 

 ing these various " points " becomes increased in the living, 

 especially if there is a thick overlying pad of fatty tissue. 

 The student must be cautioned in regard to such "points" 

 as the costal cartilages, tuberosity of the ischium, condyles 

 and tuberosities of the various long bones. Such land- 

 marks are called " points " by common consent, but in 

 reality they are very considerable areas. 



The bony parts about the popliteal region demand atten- 

 tion, and the ham-strings, which form the lateral boundaries 

 of the same. They are rendered prominent by extending 

 the leg. The tendo-Achillis is readily appreciated, espe- 

 cially if the foot is flexed. 



DISSECTION. 



Incisions. (l) Continue the median incision of the trunk to the tip of the 

 coccyx. 



(2) Make a transverse cut from the last dorsal vertebra outward (same as 

 3, page 360). 



(3) From the middle of the sacrum carry a curved incision outward over 

 the crest of the ilium to join the similar anterior one. 



