226 PRACTICAL ANATOMY. 



Insertion Lies in the posterior groove behind the 

 inner malleolus, in the groove on the astragalus, and 

 is inserted on the base of last phalanx of great toe. 



Nerve Posterior tibial. 

 FLEXOR LONGUS DIGITORUM. 



Origin Posterior surface of shaft of tibia, below 

 oblique line. 



Insertion Lies in the middle groove on the posterioi 

 surface of internal malleolus, passes beneath the 

 arch of the os calcis, and divides into four tendons, 

 which are inserted on the bases of the last pha- 

 langes of the four outer toes ; these tendons per- 

 forate the tendons of the flexor brevis digitorum. 



Nerve Posterior tibial. 



MUSCLES OF THE FOOT. 



Dorsal Region. 

 EXTENSOR BREVIS DIGITORUM. 



Origin Outer surface of os calcis, from annular liga- 

 ment and calcaneo-astragaloid ligament. 

 Insertion Passes inward across the foot and divides 

 into four tendons, which are inserted on the dorsal 

 surface of the four inner toes. 

 Nerve Anterior tibial. 



Plantar Region. 

 Plantar muscles are divided into four layers : 



First Layer. 

 ABDUCTOR POLLICIS. 



Origin Inner tubercle of os calcis. 



Insertion Inner side of base of first phalanx of great 



toe. 



Nerve Internal plantar. 

 FLEXOR BREVIS DIGITORUM. 



Origin Inner tubercle of os calcis. 



