THE LOWER LIMB 555 



nuscles: flexor brevishallucis; adductor obliquus hallucis ; adductor 

 ransversus hallucis ; and flexor brevis minimi digiti. 



Flexor Brevis Hallucis — Origin. — (i) The inner part of the plantar 

 urface of the cuboid bone (sometimes the internal surface), and 

 2) the expansions of the tibialis posticus tendon to the middle and 

 ;xtemal cuneiform bones. 



Insertion. — By means of two heads, outer and irmer. The inner 

 lead is inserted into the tubercular enlargement on the inner side 

 )f the base of the first phalanx of the great toe, in conjvmction with 

 :he abductor hallucis. The outer head is inserted into the tuber- 

 :ular enlargement on the outer side of the base of the first phalanx 

 )f the great toe, in conjunction with the adductor obUquus hallucis 

 ind adductor transversus hallucis. 



Nerve-supply. — ^The internal plantar nerve, more particularly its 

 iirst or most internal digital branch. 



Action. — ^To flex the metatarso-phalangeal joint of the great 

 toe. It may at the same time act as a very slight adductor of 

 that toe. 



The flexor brevis hallucis lies along the outer side of the tendon 

 af the abductor hallucis. It is tendinous and narrow behind, but 

 soon becomes fleshy and divides into an inner and outer head of 

 insertion, between which is the tendon of the flexor longus haUucis. 

 In each head there is a sesamoid bone. 



Adductor Obliquus Hallucis — Origin. — (i) The sheath of the 

 tendon of the peroneus longus, and (2) the plantar surfaces of the 

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



Insertion. — The tubercular enlargement on the outer side of the 

 base of the first phalanx of the great toe, in conjunction with the 

 outer head of the flexor brevis hallucis on the inner side and the 

 adductor transversus hallucis on the outer side. 



Nerve-supply. — ^The deep division of the external plantar nerve. 



Action. — (i) To adduct the great toe, and (2) to flex the meta- 

 tarso-phalangeal joint. 



The muscle lies obhquely on the outer side of the flexor brevis 

 hallucis. 



Adductor Transversus Hallucis (transversalis pedis) — Origin. — 

 (i) The inferior metatarso-phalangeal ligaments of the third, fourth, 

 and fifth toes, and (2) the transverse metatarsal Ugament. 



Insertion. — ^The tubercular enlargement on the outer side of the 

 base of the first phalanx of the great toe, in conjunction with the 

 ^adductor obhquus hallucis. 



i Nerve-supply. — ^The deep division of the external plantar nerve. 

 I Action. — (i) To adduct the great toe, and (2) to approximate 

 jthe toes to each other. 



i The muscle consists of three fleshy bundles which join into 

 one, and it lies transversely upon the heads of the four outer 

 metatarsal bones. It is to be regarded as a detached portion of 

 the adductor obliquus hallucis, which has become shifted forwards 

 Id the balls of the toes. 



