LEG AND FOOT. 



taring the digital sheath, piercing the Flexor brevis digitorum 

 tendon, and being provided with ligamenta accessoria, longa 

 and brevia, as in the hand (see page 171). [384] 



Lumbricales (four small muscles arising from the tendons of 

 the preceding). Origin; (first lumbrical) tibial side of inner- 

 most tendon ; (three outer lumbricales) adjacent sides of all four 

 tendons, by two heads each. Course of tendons ; to tibial side of 

 corresponding toes. Insertion; dorsal expansion of extensor ten- 

 don, metacarpo-phalangeal joint, and base of first phalanx of 

 each of the four outer toes, as in the hand (see page 171) . [384] 



Flexor Accessorius. Origin; (outer head) outer border of 

 inferior surface of os calcis ; (inner head) inner border of under 

 surface of os calcis. The heads unite in a flattened band. In- 

 sertion; upper aspect of Flexor longus digitorum tendons, 

 usually the inner three. [384] 



Flexor Longus Hallucis. Origin; lower two- thirds of pos- 

 terior surface of fibula; fascia over it; intermuscular septa on 

 either side. Course of tendon; under internal annular ligament 

 in a special sy no vial sheath, and then (grooving back of lower 

 end of tibia, astragalus, and under surface of sustentaculum 

 tali) forward in sole of foot over deep aspect of Flexor longus 

 digitorum tendon, sending a fibrous band to the two inner ten- 

 dons of the latter. Insertion ; base of terminal phalanx of great 

 toe. [385] 



Tibialis Posticus. Origin; middle three-fifths of fibula, be- 

 tween oblique line and interosseous border; middle third of 

 back of tibia, between vertical line and interosseous border; 

 interosseous membrane; fascia over it, and intermuscular 

 septa on either side. Course of tendon; under internal annular 

 ligament in a special sy no vial sheath, grooving back of inter- 

 nal malleolus, and then forward deeply into foot, spreading out 

 in three bands. Insertion; navicular and internal cuneiform; 

 second, third, and fourth metatarsals, cuboid, and middle and 

 external cuneiforms ; (recurrent slip) inner border of sustenta- 

 culum tali. [385] 



[297] 



