MUSCLES OF THE SOLE OF THE FOOT. . 



torum, and inserted into the expansion of the extensor tendons, and 

 into the base of the first phalanx of the four lesser toes. 



Relations. By their superficial surface with the tendons of the 

 flexor longus digitorum. By their deep surface with the third layer 

 of muscles of the sole of the foot. They pass between the digital 

 slips of the deep fascia to reach their insertion. 



Third Layer. 



Flexor brevis pollicis, 

 Adductor pollicis, 

 Flexor brevis minimi digiti, 

 Transversus pedis. 



Dissection. The tendons of the long flexors and the muscles con- 

 nected with them must be removed, to see clearly the attachments of 

 the third layer. 



The Flexor brevis pollicis arises by a pointed tendinous process 

 from the os calcis, the side of the cuboid, and from the external and 

 middle cuneiform bones ; and is inserted by two heads into the base 

 of the first phalanx of the great toe. Two sesamoid bones are de- 

 veloped in the tendons of insertion of these two heads, and the tendon 

 of the flexor longus pollicis lies in the groove between them. 



Relations. By its superficial surface with the abductor pollicis, 

 tendon of the flexor longus pollicis, and plantar fascia. By its deep 

 surface with the tarsal bones and their ligaments, the metatarsal 

 bone of the great toe, and the insertion of the tendon of the peroneus 

 longus. By its inner border with the abductor pollicis. By its outer 

 border with the adductor pollicis. 



The Adductor pollicis arises from the cuboid bone, from the sheath 

 of the tendon of the peroneus longus, and from the base of the third 

 and fourth metatarsal bones. It is inserted into the base of the first 

 phalanx of the great toe. 



Relations. By its superficial surface with the tendons of the flexor 

 longus and flexor brevis digitorum, the musculus accessorius, and 

 lumbricales. By its deep surface with the tarsal bones and liga- 

 ments, the external plantar artery and veins, the interossei muscles, 

 tendon of the peroneus longus, and metatarsal bone of the great toe. 

 By its inner border with the flexor brevis pollicis. 



The Flexor brevis minimi digiti arises from the base of the meta- 

 tarsal bone of the little toe, and from the sheath of the tendon of the 

 peroneus longus. It is inserted into the base of the first phalanx of 

 the little toe. 



Relations. By its superficial surface with the tendons of the flexor 

 longus and flexor brevis digitorum, the fourth lumbricalis, abductor 

 minimi digiti, and plantar fascia. By its deep surface with the 

 plantar interosseous muscle of the fourth metatarsal space, and the 

 metatarsal bone. 



The Transversus pedis arises by fleshy slips, from the heads of 

 the metatarsal bones of the four lesser toes. Its tendon is inserted 

 into the base of the first phalanx of the great toe. 



