TERMINAL BRANCHES. 



1343 



the tibia and the deep leg muscles and posteriorly lie the soleus and gastrocnemius 

 in the upper part of the leg. Above the ankle ihe nerve becomes superficial, and is 

 covered only by integument and the fasciae. Owing to the inward inclination of the 

 posterior tibial vessels the nerve, while pursuing a straight course, changes its rela- 

 tive position to the vessels, in the upJDer part of the leg lying to the inner side, lower 

 down behind and above the ankle attaining the outer aspect of the vessels (Fig. 

 1 121). Passing posterior to and then below the internal malleolus, the posterior 

 tibial nerve divides, under cover of the internal annular ligament, into its terminal 

 branches, the internal and the external plantar. 



Fig I I 20. 



Internal calcanean branch 

 of posterior tibial nerve 



Digital branches of 

 internal plantar nerve 



External saphenous nerve 



M iV,!^ — External saphenous nerve 



Digital branches of external plantar 

 nerve 



Superficial dissection of right foot, showing cutaneous ner\'es on plantar surface. 



Branches of the posterior tibial nerve are : (aa) the muscular, {bb) the internal 

 calca7iean, (cc) xhe articular, (^dd) the internal pla7itar and {^ee^ the external plantar. 



aa. The muscular branches (rr. musculares) supply the tibialis posticus, the soleus, the 

 flexor longus hallucis and the flexor longus digitorum. 



The nerve to the tibialis posticus supplies that muscle and sends a branch to the flexor 

 longus digitorum and one to the lower part of the soleus. At the posterior aspect of the tibialis 

 posticus it gives of? a long slender branch which accompanies the peroneal artery nearly to the 

 ankle, supplying twigs to the artery, to the periosteum of the fibula and a branch which enters 

 the nutrient canal of the fibula. 



The nerves to \\\^flexores longus hallucis and longus digitorum leave the posterior tibial 

 about the middle of the leg and pass directly to their muscles. 



