osteometry; the measurement of the bones 



141 



; 



not really difficult to take, as the two arms of the slide compass, as long, 

 parallel rods, may be placed parallel with the longitudinal axis of the 

 bone, and in an approximately horizontal plane. SC. 



3. Least breadth of the body of the bone; this is taken, with the slide 

 compass held transversely to the longitudinal axis and enclosing the 

 narrowed portion of the bone, just anterior to the tuber calcanei, and 

 immediately behind the posterior articular surface for the talus. SC. 



4. Height of the body; this is the distance from the bottom of the slight 

 depression between the raised upper 



edge of the tuber calcanei and a similar 

 one at the back of the posterior articular 

 facet for the talus, and the substratum 

 upon which the bone is resting. It is 

 best measured, as in the case of the talus, 

 by holding the bone in the proper po- 

 sition upon a glass plate of known 

 thickness, taking the measure through 

 both glass and bone, and then sub- 

 tracting the thickness of the glass plate 

 (see measurement 3 under Talus; Fig. 

 40). The measurement, without the 

 glass plate, is shown as the line ef in 

 Fig. 41. Cr or SC. 



5. Length of the body of the calcaneus 

 ( = |the effective length of the heel) ; this 

 is the length, taken along the longi- 

 tudinal axis, from the most backward 

 projecting point on the tuber to the 

 most anterior point of the anterior 

 margin of the posterior articular surface 

 for the talus (line cc' of Fig. 42). SC. 



6. Breadth of the sustentaculum; taken from the most laterally project- 

 ing point of the sustentaculum, at right angles to the longitudinal axis, 

 to the medial edge of the sulcus for the tendon of the Flexor hallucis lon- 

 gus. This is a very uncertain measure, unless the line is taken exactly 

 at right angles to the longitudinal axes, as the medial limit is placed upon 

 an oblique line, which changes its relationship to the lateral one at every 

 point. 



7. Height of the tuber calcanei; taken sagittally through the tuber from 

 the highest point above to the lowest point in the medial tuberal process, 

 as far anteriorly as possible. SC or Cr. 



8. Breadth of the tuber calcanei; taken across the tuber, at right angles 

 to the previous one; the maximum breadth. SC or Cr. 



9 and 10. Length and Breadth respectively of the posterior articular 

 surf ace for the talus. (Fig. 42, ef and gh). SC. 



42. — Right calcaneus, from 

 showing lines for measure- 

 (After Reicher.) 



