THE MUSCULAR SYSTEM. 165 



toes on their outer sides; action, extends the phalanges of the four 

 inner toes and the first phalanx of the great toe; nerve, the an- 

 terior tibial. 



Plantar Region. 

 The muscles of this region are divided into four sets. 



First Set. 



ABDUCTOR POLLICIS. Origin, from the internal annular 

 ligament, from the inner tubercle of the os calcis, from the inter- 

 muscular septum on its outer side ; plantar fascia ; insertion, into 

 the base of the first phalanx of the great toe on its inner side; 

 action, abducts the great toe; nerve, branch of the internal 

 plantar. 



FLEXOR BREVIS DIGITORUM (PERFORATUS). Origin, from 

 the inner tubercle of the os calcis, from the plantar fascia and 

 the intermuscular septa between it and the muscles on either 

 side ; insertion, into the second phalanges by a process on either 

 side, allowing the passage of the tendon of the flexor longus 

 digitorum; action, flexes first lesser toes; nerve, from the in- 

 ternal plantar. 



ABDUCTOR MINIMI DIGITI. Origin, from the plantar fascia, 

 from the os calcis in front of ihe tubercle, and from the inter- 

 muscular septum on its inner side ; insertion, into the first 

 phalanx of the little toe on its outer side; action, abducts little 

 toe; nerve, external plantar. 



Second Set. 



FLEXOR ACCESSORIUS. Origin, by two heads, one from the 

 os calcis in front of the outer tubercle, the other from the inner 

 surface of the os calcis and the calcaneo-scaphoid ligament; in- 

 sertion, by a common tendon into the tendon of the flexor longus 

 digitorum; action, accessory to the long flexor; nerve, external 

 plantar. 



LUMBRICALES. Four small muscles. Origin, from the ten- 

 dons of the flexor longus digitorum, after their division, each 

 one arising from two tendons; insertion, into the base of the 

 first phalanx of the same toe and the tendinous expansion of the 

 extensor longus digitorum ; nerves, the external plantar nerve 

 supplies tho two external, the internal plantar nerve the two in- 

 ternal, 



