MUSCLES AND FASCIA OF LOWER EXTREMITY 171 



of the flexor longus digitorum tendon, each attached 

 to two tendons, except the most internal one; they pass 

 to the inner side of the four outer toes; inserted into 

 the bases of the first phalanges. 



THE INTERNAL GROUP. Abductor Hallucis, flexor 

 brevis hallucis, and adductor hallucis (oblique trans- 

 verse portions). 



THE EXTERNAL GROUP. Abductor Minimi Digiti, 

 and flexor brevis minimi digiti. 



Actions. Popliteus flexes the knee and rotates the 

 leg inward, pulls on the capsule of the joint, and keeps 

 the popliteal bursa open. The dorsum of the foot 

 and anterior surface of the leg is the extensor surface; 

 the opposite side is the flexor surface, so that raising 

 the foot toward the front of the leg is really extension, 

 and depressing it is flexion; it is customary to apply 

 reverse terms to these acts. 



Gastrocnemius flexes the knee, extends the ankle, 

 combines with the soleus, and lifts the heel or raises 

 the body on toes. 



Tibialis anticus and peroneus tertius flex the ankle; 

 the former rotates inward, adducts, raises the first 

 metatarsal bone. 



Tibialis posticus, peroneus longus and brevis are 

 extensors of the ankle-joint. Tibialis posticus and 

 flexors of the toes rotate the foot in. The three peronei 

 and extensors of the toes rotate outward. 



Peroneus longus strengthens the transverse arch, lifts 

 the outer border of the foot in walking, extends the 

 foot, depresses the first metatarsal, abducts the fore- 

 foot, rotates outward. 



Flexors and extensors of the toes, interossei, and 

 lumbricales act as do the corresponding muscles of the 

 hand. 



Flexor accessorius modifies the action of the flexor 

 longus digitorum, as those tendons cannot enter the 

 foot in a straight line. 



The extensor brevis digitorum does the same for the 



