ANATOMY OF THE UPPER EXTREMITY. 155 



servable expressions of the conditions inherent at 

 the time. 



In making such examinations while the subject 

 is standing, he is requested to hold out his hands, 

 or sometimes to hold out the hands with the palms 

 downwards. This affords the opportunity of ob- 

 serving the free or disengaged hands. The pos- 

 tures, the symmetry, presence of any movements, 

 the coincident balance of the head or spine, etc., 

 can be noticed while observing specially the 

 hands. 



The upper extremity in man consists of the fol- 

 lowing parts : The upper arm, with the humerus 

 as its bone, which is articulated at the shoulder 

 with the scapula or blade-bone. The lower end of 

 the humerus articulates with the radius and ulna, 

 the bones of the forearm. The forearm articulates 

 with the wrist, which is made up of eight small 

 bones, collectively spoken of as the carpus. The 

 palm of the hand consists of five metacarpal 

 bones, each of which carries its own digit. These 

 bones, termed collectively the metacarpus, are 

 capable of slight movement, enabling them to be 

 approximated like a bundle of sticks tied together, 

 or spread out. The junction of a metacarpal bone 

 with its digit is called the metacarpo-phalangeal 

 joint, or the knuckle. The individual bones of the 

 fingers and thumb are termed " internodes." 



For the general convenience of description, I have 

 illustrated and tabulated eight typical postures 

 indicative of positions commonly seen. 



Perhaps one of the best known spontaneous 



