164 HUMAN ANATOMY. 



and from the intermuscular septum; it passes behind the in- 

 ternal malleolus; insertion, into the base of the last phalanx of 

 the great toe; nerve, posterior tibial. 



ELEXOR LONGUS DIGITORUM (PERFORANS). Origin, from 

 the posterior aspect of the tibia, below the oblique line ; it passes 

 behind the internal malleolus; insertion, into the bases of the 

 last phalanges of the four lesser toes, passing through the division 

 in the tendons of the flexor brevis digitorum; action, flexes the 

 phalanges and, continuing, extends the foot on the leg; nerve, 

 the posterior tibial. 



TIBIALIS POSTICUS. Origin, from the posterior aspect of 

 the shaft of the tibia, and from the upper two-thirds of the shaft 

 of the fibula, and from the whole length of the interosseous mem- 

 brane and the intermuscular septa on either side of it ; it passes 

 behind the inner malleolus; insertion, into the internal cunei- 

 form bone and the tuberosity of the scaphoid; it contains a 

 sesamoid bone in its tendon ; action, extends the tarsus upon the 

 leg; nerve, the posterior tibial. 



Filular Region. 



PERONEUS LONGUS. Origin, from the upper two-thirds of 

 the shaft of the fibula, the head of the fibula, the intermuscular 

 septa, and the deep fascia; it passes behind the outer malleolus 

 along with the peroneus brevis; insertion, into the base of the 

 metatarsal bone of the great toe ; this tendon changes its course 

 twice, first at the external malleolus, second at the cuboid bone, 

 and usually has a sesamoid bone developed in its tendon; action, 

 extends and everts the foot upon the leg; nerve, musculo-cutane- 

 ous branch of the external popliteal. 



PERONEUS BREVIS. Origin, from the outer and middle 

 third of the fibula and the intermuscular septa on either side; 

 insertion, into the upper surface of the base -of the metatarsal 

 bone of the little toe; action, extends the foot upon the leg; 

 nerve, musculo-cutaneous branch of the external popliteal. 



MUSCLES OF THE FOOT. 



Dorsal Region. 



EXTENSOR BREVIS DIGITORUM. Origin, from the external 

 calcaneo-astragaloid ligament, from the annular ligament, and 

 from the outer side of the os calcis ; insertion, by four tendons 

 the first one into the first phalanx of the great toe, the other three 

 into the long extensor tendons of the second, third, and fourth 



