MUSCLES ON THE SOLE OF THE FOOT. 393 



Use. To increase the flexion of the toes, and to draw them 

 inwards. 



On the inside of the foot, and under the common flexors, are 

 the muscles which are considered as exclusively appropriated 

 to the great toe, viz. 



1. Abductor Pollicis 



Arises, from the internal side of the tuberosity of the os 

 calcis, and from a ligament which extends from this tuberosity 

 to the sheath of the tendon of the tibialis posticus muscle, and 

 also from the internal and inferior side of the os navicu- 

 lare and cuneiforme internurn. It likewise arises from that 

 portion of the aponeurosis plantaris, which separates it from 

 the short flexor of the toes, and many of its fibres appear to be 

 connected with the ligaments which pass from the posterior to 

 the anterior bones of the foot : as it passes under the cuneiform 

 bone, a portion of its lower surface is tendinous. 



It is inseparably connected to the flexor of the great toe, and 

 is inserted into the internal sesamoid bone, and the inferior 

 and internal part of the root of the first bones of the great toe. 



This muscle not only separates the great toe from the other 

 toes, but it must increase the curvature, or arched form of the 

 foot. 



2. Flexor Brevis Pollicis Pedis, 



Arises , tendinous, from the under and forepart of the os 

 calcis, where it joins with the os cuboides, from the os cunei- 

 forme externum, and is inseparably united with the abductor 

 and adductor pollicis. 



Inserted, into the internal and external sesamoid bones, along 

 with the abductor and adductor pollicis, and into the root of 

 the first joint of the great toe. 



Use. To bend the first joint. 



3. Adductor Pollicis Pedis, 



Arises, by a long thin tendon, from the os calcis, from the 

 os cuboides, from the os cuneiforme externum, and from the 

 root of the metatarsal bone of the second toe. 



