222 ATLAS AND TEXT-BOOK OF HUMAN ANATOMY. 



Fig. 306. — The muscles of the anterior surface of the lower leg and of the dorsum of the foot. The 

 transverse crural ligament has been removed. 



Fig. 307. — The muscles of the lower leg and of the dorsum of the foot, seen from the side. 



digitorum brevis and pass to the ungual phalanges. (Further details as to the relations of the 

 tendons are given on page 231.) 



The muscle is supplied by the tibial nerve and flexes the second to the fifth toes (especially the ungual phalanges). 



The flexor hallucis longus (Figs. 305 and 311) resembles the other two muscles in this group, 

 but it is somewhat shorter and stronger and, at the same time, distinctly penniform. It is the 

 most external muscle of the group and preserves this relation throughout the leg. It arises by a 

 short tendon from the posterior surface and outer border of the fibula, below the origin of the 

 soleus, i. e., from the lower two-thirds of the bone, extending downward to just above the malle- 

 olus. A thick tendon which is situated in the center of the broad muscle, commences in the middle 

 of the leg and passes through the outer compartment of the laciniate ligament to the sole of the 

 foot (Fig. 311), where it crosses the tendon of the flexor digitorum and runs to the ungual phalanx 

 of the great toe and indirectly also to the other toes. 



The muscle is supplied from the tibial nerve. It flexes the great toe and indirectly also the four lesser toes. 



THE MUSCLES OF THE OUTER SIDE OF THE LEG, THE PERON^L 



The posterior borders of both of these muscles are in relation with the soleus and with the deep 

 flexor group, while their anterior margins are in relation with the muscles of the extensor group, 

 from which they are separated in the lower third of the leg by the lower portion of the shaft of the 

 fibula and the external malleolus. They are situated in the external crural region. 



The peronaeus longus (Figs. 306 and 307) is a very long, distinctly semipenniform muscle, 

 which arises by indistinctly separated anterior and posterior heads. The anterior head is a short 

 tendon from the head of the fibula, the contiguous portion of the external condyle of the tibia and 

 the crural fascia; the posterior springs from the upper two-thirds of the outer surface and outer 

 border of the fibula. At the junction of the middle and upper thirds of the leg, both heads 

 pass into a slightly flattened tendon upon the anterior surface of the muscle, which broadens as 

 it descends and passes beneath the retinacula peronceorum (Fig. 307) (see page 230) in the groove 

 behind the external malleolus, to the outer side of the sole of the foot. Deep down in the sole 

 the tendon lies in the groove of the cuboid (Figs. 311 and 312), is provided with a thick sesamoid 

 cartilage or sesamoid bone, and passes to the tuberosity of the metatarsal bone of the great toe, 

 some fibers being prolonged to the internal cuneiform and to the base of the second metatarsal bone. 



The peronaeus longus almost entirely conceals the origin of the peronaeus brevis; in the lower 

 part of the leg the latter may be seen both in front of and behind the margins of the peronaeus 

 longus or its tendon. 



The peronaeus longus is supplied from the peroneal nerve. It abducts the foot, assists in producing plantar flexion, 

 and elevates the outer margin of the sole (pronation). 



