28 LANDMARKS MEDICAL AND SURGICAL. 



are freest between the third and the sixth cervical vertebrae, 

 between the eleventh dorsal and the second lumbar, and 

 between the last lumbar and the sacrum. This is well marked 

 in severe cases of opisthotonos, where the body is supported 

 on the back of the head and heels. 4 



Still better may it be observed when a mountebank bends 

 backwards, and touches the ground with his head. 



The lateral movement is freest in the neck and the loins. 



The movement of torsion or rotation round its own axis 

 may be proved by the following experiment : Seated upright, 

 with the back and shoulders well applied against the back of 

 a chair, we can turn the head and neck as far as 70. Leaning 

 forwards so as to let the dorsal and lumbar vertebrae come 

 into play, we can turn 30 more. 



58. Position and motions of scapula. There are a few 

 points worthy of observation about the scapula. It covers 

 the ribs from the second to the seventh inclusive^ We can 

 feel its superior angle covered by the trapezius. The inferior 

 angle is covered by the latissimus dorsi, which keeps it well 

 applied against the ribs in the strong and athletic ; but in 

 weak and consumptive persons the lower angles of the 

 scapulae project like wings hence the term ' scapulae 

 alatse.' 



A line drawn horizontally from the spine of the sixth 

 dorsal vertebra over the inferior angle of the scapula gives 

 the upper border of the latissimus dorsi. Another line drawn 

 from the root of the spine of the scapula to the spine of the 

 last dorsal vertebra gives the lower border of the trapezius, 

 which stands a little in relief. 



59. The sliding movement of the scapula on the chest 

 can be properly understood only on the living subject. It 

 can move not only upwards and downwards as in shrugging 

 the shoulders backwards and forwards as in throwing back 

 the shoulders but it has a rotatory movement round a 

 movable centre. This rotation is seen while the arm is being 

 raised from the horizontal to the vertical position, and is 

 effected by the co-operation of the trapezius with the serratus 

 magnus. The glenoid cavity is thus made to look upwards, 



