374 MUSCLES ON THE BACK OF THE HAND. 



expansion from the extensor digitorum communis, which covers 

 the posterior part of the fore-finger. 



Use. To draw the fore-finger outwards towards the thumb, 

 and extend it obliquely. 



2. Posterior Indicis. 



Arises tendinous and fleshy, from the root and inner part of 

 the metacarpal bone that sustains the fore-finger. 



Inserted into the inner side of the tendinous expansion which 

 is sent off from the extensor digitorum communis, along the 

 posterior part of the fore-finger. 



Use. To extend the fore-finger obliquely, and to draw it 

 inwards. 



3. Prior Annularis. 



Arises, from the root of the outside of the metacarpal bone 

 that sustains the ring finger. 



Inserted into the outside of the tendinous expansion of the 

 extensor digitorum communis which covers the ring finger. 



Use. To extend and pull the ring finger towards the thumb. 



4. Interosseous Auricularis, 



Arises, from the root and outer side of the metacarpal bone 

 of the little finger ; and is 



Inserted into the outside of the tendinous expansion of the 

 extensor digitorum communis, which covers the posterior part of 

 the little finger. 



Use. To extend and draw the little finger outwards. 



On the back of the hand three muscles of the same kind are 

 to be seen, which also appear on the palm. 



Posterior Interosseous Muscles. 



1 . Prior Medii, 



Arises, by two origins, from the root of the metacarpal bones 



that sustain the fore and middle fingers externally, and next each 



other: runs along the outside of the middle finger; and, being 



conspicuous on both sides of the hand, is 



