74 ANTHROPOLOGY. 
Flexor digitorum perforans arises from the posterior flat surface of the 
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 and 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 longus 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 Foor. 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 lamine. 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 lumbricahs. The third layer consists of the flexor pollicis 
brevis, adductor pollicis, transversalis pedis, and flexor minimi digiti. In 
the fourth are the interosseous and the tendon of the peronseus longus. 
Hetensor digitorum 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 caleis, 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 perjoratus 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 minim digiti arises principally from the outer side of the os 
ealcis, 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. 
LIumbricales 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, 
780 
