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. Pulls 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 hypotarsus 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. 



