178 .PHYSICAL EXPRESSION. 



hajid. By daily recording the most common in- 

 voluntary postures of the free hand, we obtain 

 indications of the daily condition of the nerve- 

 mechanism corresponding. 



In analyzing any posture of the hand we may 

 consider the bearing upon the subject of the follow- 

 ing principles, or points of analysis. These are the 

 same that have been used in the tables. 



I. Every posture can be described in anatomical 

 language, giving the position of each joint of the 

 limb. 



II. Consider the posture of the small parts of 

 the limb as distinguished from the larger parts. 

 In chorea the movements of the small parts are 

 much more obvious, and probably much more 

 frequent than those of the larger parts ; more move- 

 ment is seen in the fingers than in the elbow and 

 wrist. A slight amount of brain disease will inter- 

 fere more with the use of the fingers than with 

 the use of the upper arm. A man may be able to> 

 stretch out his hand and grasp an orange, but be 

 quite unable to write, or to pick up a pin from 

 the table. 



, III. Consider the different relative postures seen 

 in the large and small joints. 



Interdifferentiation of the postures of the large 

 and small joints may give important indications; 

 the large joint may be paretic or weak, while the 

 small joints are in extension, from irritability of 

 the nerve-centres which govern these movements. 

 In such a case there would be an interdifferenti- 

 ation of the nerve-centres governing the different 



