SOLE OF THE FOOT 395 



position in the sole, and hides the interosseous muscles to a 

 great extent. It lies to the lateral side of the flexor hallucis 

 brevis. 



The transverse head of the adductor hallucis is placed 

 transversely across the heads of the metatarsal bones and the 

 plantar ligaments of the metatarso-phalangeal joints. 



The flexor digiti quinti brevis (O.T. minimi digiti) lies upon 

 the fifth metatarsal bone. 



The deep division of the lateral plantar nerve and the 

 plantar arterial arch are partially exposed, but they will be 

 more fully displayed at a later stage. 



Dissection. Clean all the above-named muscles from their 

 origins to their insertions. Clean also the exposed part of the 

 plantar arch. 



M. Flexor Hallucis Brevis. The short flexor of the great 

 toe arises from the slip from the tendon of the tibialis posterior 

 muscle which goes to the second and third cuneiform bones 

 and from the adjoining part of the cuboid bone. It is narrow 

 and tendinous at its origin, but it soon divides into two separate 

 fleshy bellies, which are ultimately inserted one upon each 

 side of the base of the proximal phalanx of the great toe. 

 In the tendons of insertion two large sesamoid bones are 

 developed (Fig. 1 74). The medial head of the flexor hallucis 

 brevis is closely connected with the tendon of the abductor 

 hallucis, and is inserted in common with it. The flexor 

 hallucis brevis is supplied by the medial plantar nerve. It 

 is a flexor of the metatarso-phalangeal joint of the great toe. 



M. Adductor Hallucis (O.T. Adductor Obliquus Hallucis 

 and Adductor Trans versus Hallucis). The adductor hallucis 

 consists of two separate portions called the oblique and the 

 transverse heads of the muscle. The oblique head arises 

 from the sheath of the peronaeus longus tendon and from 

 the bases of the second, third, and fourth metatarsal bones. 

 It tapers as it approaches the root of the hallux, and is 

 inserted, with the lateral head of the flexor hallucis brevis, 

 into the lateral aspect of the base of the proximal phalanx 

 of the great toe. It is supplied by the deep division of 

 the lateral plantar nerve. The transverse head springs by 

 a series of slips from the plantar metatarso-phalangeal 

 ligaments of the third, fourth, and fifth toes, and proceeds 

 transversely medially, under cover of the flexor tendons, 

 to find insertion into the lateral side of the base of the 



