590 A MANUAL OF ANATOMY. 



brevis digitorum muscles blend with the margins of the 

 long extensor tendons along the first phalanges. 



Nerve Supply. The anterior tibial. 



Action. To extend the toes, to flex the foot upon the 

 leg. The action upon the toes is most marked upon the 

 first phalanges, the extension of the second and third 

 phalanges being effected through the interossei and lumbri- 

 cales. 



Extensor Proprius Hallucis. Figs. 123, 124. 



Origin. From the middle two-fourths of the anterior 

 surface (antero-internal) of the fibula and from the interos- 

 seous membrane adjacent to this origin. 



Insertion. Into the dorsal surface of the base of the last 

 phalanx of the great toe. At the metatarsophalangeal 

 articulation a fibrous expansion from the tendon passes to 

 the lateral ligaments of the articulation. 



Nerve Supply. The anterior tibial. 



Action. To extend the great toe, to flex the foot, to 

 adduct the fore part of the foot, to raise (invert) the inner 

 border of the foot. Due to the tendon being crossed by 

 the lower leg of the -< ligament. 



See Attachments of Annular Ligament, page 585. 



Peroneus Tertius. Figs. 123, 124. 



Origin. From the lower fourth of the anterior surface 

 of the fibula, being continuous with the extensor longus 

 digitorum, from the adjacent interosseous membrane, and 

 intermuscular fascia. 



Insertion. Into the upper surface of the base of the fifth 

 metatarsal bone. 



Nerve Supply. The anterior tibial. 



Action. To flex the ankle-joint, to raise the outer border 

 of the foot (eversion), to abduct the fore part of the foot. 



