PLANTAR REGION. 



431 



Third Layer. 



Flexor Brevis Pollicis. 

 Adductor Pollicis. 



Flexor Brevis Minimi Digiti. 

 Transversus Pedis. 



Fig. 263. Muscles of the Sole of the Foot. 



The Flexor Brevis Pollicis arises, by a pointed tendinous process, from the 

 inner border of the cuboid bone, from the contiguous portion of the external 

 cuneiform, and from the prolongation of the tendon of the Tibialis Posticus, 

 which is attached to that bone. The muscle divides, in front, into two portions, 

 which are inserted into the inner and outer sides of the base of the first phalanx 

 of the great toe, a sesamoid bone being 

 developed in each tendon at its insertion. 

 The inner head of this muscle is blended 

 with the Abductor Pollicis previous to 

 its insertion ; the outer head, with the 

 Adductor Pollicis ; and the tendon of the 

 Flexor Longus Pollicis lies in a groove 

 between them. 



Relations. By its superficial surface, 

 with the Abductor Pollicis, the tendon 

 of the Flexor Longus Pollicis and plantar 

 fascia. By its deep surface, with the ten- 

 don of the Peroneus Longus, and meta- 

 tarsal bone of the great toe. By its 

 inner border, with the Abductor Pollicis. 

 By its outer border, with the Adductor 

 Pollicis. 



The Adductor Pollicis is a large, thick, 

 fleshy mass, passing obliquely across the 

 foot, and occupying the hollow space 

 between the four outer metatarsal bones. 

 It arises from the tarsal extremities of 

 the second, third, and fourth metatarsal 

 bones, and from the sheath of the tendon 

 of the Peroneus Longus, and is inserted, 

 together with the outer head of the Flexor 

 Brevis Pollicis, into the outer side of the 

 base of the first phalanx of the great toe. 



The Flexor Brevis Minimi Digiti lies 

 on the metatarsal bone of the little toe, 

 and much resembles one of the interossei. 

 It arises from the base of the metatarsal 

 bone of the little toe, and from the sheath 

 of the Peroneus Longus; its tendon is 

 inserted into the base of the first phalanx 

 of the little toe, on its outer side. 



Relations. By its superficial surface, 

 with the plantar fascia and tendon of the 

 Abductor Minimi Digiti. By its deep 

 surface, with the fifth metatarsal bone. 



The Transversus Pedis is a narrow, flat, muscular fasciculus, stretched trans- 

 versely across the heads of the metatarsal bones, between them and the flexor 

 tendons. It arises from the under surface of the head of the fifth metatarsal 

 bone, and from the transverse ligament of the metatarsus; and is inserted into 

 the outer side of the first phalanx of the great toe; its fibres being blended with 

 the tendon of insertion of the Adductor Pollicis. 



