MYOLOGY 119 



Shape. — A broad muscular sheet. 



Action. — Assists the flexor perforatus medius primus pedis. 



Tibialis Anticiis (Fig. 24, No. 22). Location. — In the anterior 

 tibial region. 



Origin^ — The muscular belly may be easily divided into two parts. 

 The inner head extends from the head of the tibia immediately 

 beneath theiperoneus longus. The outer head arises by a strong 

 tendon from a depression on the antero-inferior ridge of the outer 

 condyle of the femur. 



Insertion. — The tendon passing through the fibrous ligamentous 

 loop just above the tibial condyles, inserts to a tubercle on the 

 shaft just below the head of the tarso-metatarsus. 



Shape. — Large, fusiform. 



Relations. — Beneath the peroneus longus. 



Action. — Flexes the metatarsus upon the tibia. 



Extensor Longus Digitorum (Fig. 25, No. G, 6). Location. — An- 

 terior tibial region. 



Origin. — From the inferior portion of the crest and a portion of 

 the shaft of the fibula. 



Insertion. — It becomes tendinous at the lower third of the bone, 

 passing imder the bony ridge just above the condyle in front, 

 and over the ankle-joint. It is bound down by firm fascia, and at 

 the trochlea of the basal toe joints, divides into three small tendin- 

 ous slips. These pass over the superior part of the second, the 

 third, and the fourth toes, bifurcating in their course, and are 

 inserted to the distal ones. 



Shape. — Long, penniform, with a long, slender tendon. 



Relations. — Immediately below the tibiaUs anticus. 



Action. — Extends the digits as their long extensor. 



Extensor Hallucis Brevis (Fig. 25, No. G, 4). Location. — The 

 anterior metatarsal region, along the antero-internal edge. 



Origin. — From just below the summit of the antero-internal part 

 of the head of the tarso-metatarsus, and from the adjacent shaft 

 below, and from the tendon of the tibialis anticus. 



Insertion. — Into the process at the superior part of the bone of 

 the bony claw of the hallux. 



Shape. — Slender, thin in diameter, with a long, slender tendon. 



Relations. — Superiorly, with the antero-internal edge of the 

 metatarsus and inferiorly, its tendon with the top of the hallux. 



Action. — Extends the hallux. 



