PLANTAR. 



589 



Fig. 295. The Plantar Nerves. 



these branches accompany the superior and inferior internal articular arteries, and 

 a third the azj^gos. 



The muscular brandies, four or five in number, arise from the nerve as it lies 

 between the two heads of the Gastrocnemius muscle ; they supply this muscle, 

 the Plantaris, Soleus, and Popliteus. 



The external or short saphenous nerve descends between the two heads of the 

 Gastrocnemius muscle, and, about the middle of the back of the leg, pierces the 

 deep fascia, and receives a communicating branch (communicans peronei) from the 

 external popliteal nerve. The nerve then continues its course down the leg near 

 the outer margin of the tendo Achillis, in company with the external saphenous 

 vein, winds round the outer malleoius, and is distributed to the integument along 

 the outer side of the foot and little toe, communicating on the dorsum of the foot 

 with the musculo-cutaueous nerve. 



The Posterior Tibial nerve commences at the lower border of the Popliteus 

 muscle, and passes along the back part of the leg with the posterior tibial vessels 

 to the interval between the inner malleoius and the heel, where it divides into the 

 external and internal plantar nerves. It lies upon the deep muscles of the leg, 

 and is covered by the deep fascia, the superficial muscles, and integument. In 

 the upper part of its course,' it lies to the inner side of the posterior tibial artery ; 

 but it soon crosses that vessel, and lies to its outer side as far as the ankle. In 

 the lower third of the leg, it is placed parallel with the inner margin of the tendo 

 Achillis. 



The branches of the posterior tibial 

 nerve are muscular and plantar cutaneous. 



The 'muscular branches arise either 

 separately or by a common trunk from 

 the upper part of the nerve. They supply 

 the Tibialis posticus, Flexor longus digi- 

 torum, and Flexor longus pollicis muscles ; 

 the branch to the latter muscle accompanies 

 the peroneal artery. 



The plantar cutaneous branch perforates 

 the internal annular ligament, and sup- 

 plies the integument of the heel and inner 

 side of the sole of the foot. 



The internal plantar nerve (fig. 295), 

 the larger of the two terminal branches 

 of the posterior tibial, accompanies the 

 internal, plantar artery along the inner 

 side of the foot. From its origin at the 

 inner ankle it passes forwards between 

 the Abductor pollicis and Flexor brevis 

 digitorum, divides opposite the bases of 

 the metatarsal bones into four digital 

 branches, and communicates with the 

 external plantar nerve. 



Branches. In its course, the internal 

 plantar nerve gives off cutaneous branches, 

 which pierce the plantar fascia, and supply 

 the integument of the sole of the foot; 

 muscular branches, which supply the 

 Abductor pollicis and Flexor brevis digi- 

 torum ; articular branches to the articulations of the tarsus and metatarsus ; and 

 four digital branches. These pierce the plantar fascia in the clefts between the 

 toes, and are distributed in the following manner : The first supplies the inner 

 border of the great toe, and sends a filament to the Flexor brevis pollicis muscle; 

 the second bifurcates, to supply the adjacent sides of the great and second toes, 



Hxt&rnal 



