MYOLOGY 121 



inserted to the inner tubercle of. the base of the first phalanx of 

 the outer or fourth toe. 



Shape. — Long, slender. 



Relations. — Posteriorly with the metatarsus. 



Action. — ^PuUs the fourth toe upward and inward. 



Flexor Hallucis Brevis. Location. — Postero-internal side of the 

 metatarsus. 



Origin. — Side and lower margin of the inner aspect of the hypo- 

 tarsus of the tarso-metatarsus and from the shaft of this bone 

 immediately below it. 



Insertion. — Winds round inner side of basal joint of the hallux 

 and is inserted on its under side. 



Shape. — Small flat muscle gradually tapering into a tendon. 



Relations. — ^Posteriorly with the metatarsus. 



Action. — To flex the hallux. 



Extensor Annularis Brevis. Location. — On postero-external side 

 of metatarsus. 



Origin. — ^External aspect of the h3rpotarsus and the shaft below. 



Insertion. — Supero-external part of the basal phalanx of the 

 fourth toe. 



Shape. — Small flat muscle. 



Relations. — ^Posteriorly with the metatarsus. 



Action. — Extensor of the fourth toe. 



Tibialis Posticus (Fig. 24, No. 23). Location.— In the posterior 

 tibial region. 



Origin. — From the whole shaft of the fibula below the insertion 

 of the biceps flexor cruris, and from the shaft of the tibia a short 

 distance below this insertion. Also from the interosseous mem- 

 brane, and the adjacent surface of the tibial shaft. 



Insertion. — Passing in front of the external malleolus, crossing the 

 ankle-joint, finally inserted into the outer edge of the summit of 

 the tarso-metatarsal bone. 



Shape. — ^Long, subcylindrical. 



Relations. — Medially, with the flexor perforans digitorum pedis; 

 superiorly, with the postero-external portion of the tibia. 



Action. — Extends the metatarsus upon the tibia. 



Flexor Perforatus Indicis Secundus Pedis (Fig. 17, No. 5). Loca- 

 tion. — The posterior tibial region. 



Origin. — From the external surface of the outer condyle of the 

 femur, just below the head of the gastrocnemius. 



