The Foteyrm. 75 



tion inwards, i.e., pronation. The remaining muscles are 

 concerned with the movements of the hand rather than fore- 

 arm, and these muscles are : i. The extensor carpi radialis 

 longior and brevior, the former from the lower one-third 

 of the external supracondyloid ridge, into the radial side 

 of the metncarpal bone of the index finger, and the latter, 

 from the external condyle, into the metacarpal bone of the 

 middle finger. Their action is to extend, as their names 

 indicate, the wrist towards the radial side. 2. ^te flexor 

 carpi ulnaris, from the inner condyle, inner margin of the 

 olecranon and posterior border of the ulna, into the pisi- 

 form bone, flexes the wrist towards the ulnar side. 3. The 

 flexor sublimis digitorum from the internal condyle, inner 

 margin of the coronoid and the oblique line of the radius, 

 into the middle phalanges, and 4, the flexor profundus, 

 from the upper three fourths of the anterior and inner sur- 

 faces of the ulna, into the last phalanges, are, as their names 

 indicate, the superficial and deep flexors of the fingers. 5. 

 The extensor communis digitorum ,the extensor minimi digiti, 

 and the extensor indicis, the two former from the external 

 condyle and the latter from the lower part of the posterior 

 surface of the ulna, into the back part of the second and 

 third phalanges, are the extensors of the fingers. 6. The 

 flexor longus pollicis, from the anterior surface of the 

 radius below the oblique line, into the last phalanx of the 

 thumb, flexes this phalanx. 7. The extensor ossis meta. 

 carpi pollicis, from the posterior surfaces of the ulna and 

 radius ; the extensor primi internodii, from the posterior 

 surface of the radius and the extensor secundi internodii 

 from the posterior surface of the ulna, are inserted into 

 the metacarpal bone and the first and second phalanges, 

 respectively, of the thumb and extend these bones. All 

 the muscles arising from the internal condyle, and insert- 

 ed into the fingers or carpus, are, in addition to the actions 



