74 ANTHROPOLOGY. 



Flexor digitorum perforans arises from the posterior flat surface of tlie 

 tibia, and is inserted by four tendons into the base of the last phalanx of 

 each of the four lesser toes. Use : to flex the metatarsus and all the 

 phalanges of the toes. 



Tibialis posticus arises from the posterior and internal part of the fibula, 

 and is inserted into a tuberosity on the inferior afid internal part of the os 

 naviculare. Use : to extend the ankle, and to raise the inner edge of the 

 foot from the ground. 



Flexor pollicis longibs arises mainly from the two inferior thirds of the 

 fibula, and is inserted into the base of the last phalanx of the great toe. 

 Use : to flex this toe, to extend the ankle, and to adduct the foot. 



6. Muscles of the Foot. There is but one muscle in the upper surface 

 of the foot, the extensor digitorum brevis. Those in the sole of the foot are 

 very numerous, and may be divided into four laminae. The muscles of the 

 first lamina are, the abductor pollicis, flexor digitorum brevis, and abductor 

 minimi digiti; in the second layer are the long flexor tendons, the accessory 

 muscle, and the lumbricalis. The third layer consists of the flexor pollicis 

 brevis, adductor pollicis, trans versalis pedis, and flexor minimi digiti. In 

 the fourth are the interosseous and the tendon of the peronoeus longus. 



Extensor digitorma brevis arises from the upper part of the os calcis, 

 from the cuboid bone, the astragalus, and the annular ligament ; it ends in 

 four tendons, which are inserted into the upper part of all the four large 

 toes. -It serves to extend the toes and to rotate the anterior part of the foot 

 outwards. 



Abductor pollicis arises mainly from the inner part of the os calcis, and 

 is inserted into the internal sesamoid bone, and into the internal side of the 

 first phalanx of the great toe. It serves to flex the great toe and to separate 

 it from the rest. 



Flexor digitorum brevis perforatus arises from the inferior and internal 

 part of the os calcis, and about the middle of the foot divides into four 

 muscles, each ending in tendons. Each tendon is perforated by the long 

 flexor tendon, and is ultimately inserted into the lateral borders of the second 

 phalanges. It assists to preserve the arch of the foot, and helps the long 

 flexor muscle. 



Abductor minimi digiti arises principally from the outer side of the os 

 calcis, and is inserted into the outer side of the base of the first phalanx of 

 the little toe and into the adjoining surface of the metatarsal bones. It 

 flexes the little toe and separates it from the others. 



Accessorius arises bifurcated from the inferior and lateral borders of the 

 OS calcis, and is inserted into the upper and outer part of the tendon of the 

 flexor digitorum longus just before it divides. It assists the long flexor, and 

 counteracts its obliquity. 



Lrimbricales are four small muscles which arise from the angles between 

 the tendons of the flexor digitorum longus ; each is inserted into the internal 

 side of the first phalanx of the four toes, there being none for the great toe. 

 . They adduct and assist in flexing the four toes. 



Flexor pollicis brevis arises from the anterior inferior part of the os calcis,v 

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