METATAESALGIA. 243 



branch, the communicans tibialis, to join the communicans 

 fibularis from the peroneal, and to form the external or short 

 saphenous ; and muscular branches to the two heads of the 

 gastrocnemius, the plantaris, the popliteus, and part of the 

 soleus. The branch to the popliteus is of interest, because it 

 arises just as the nerve passes behind the upper border of the 

 muscle, and passing posterior to the muscle winds round its 

 lower border to supply the same on its deep or anterior aspect. 



The posterior tibial, the continuation of the internal popliteal, 

 runs down the back of the leg deeply placed, supplying in its 

 course the rest of the soleus, the tibialis posticus, the flexor 

 longus digitorum and the flexor longus hallucis, and divides a 

 little above the ankle joint, about half-way between the internal 

 malleolus and the heel, into the internal and external plantar 

 branches, of which the internal is the larger. 



The external plantar nerve supplies the following muscles, the 

 abductor minimi digiti, flexor brevis minimi digiti, accessorius, 

 the outer two lumbricals, all the interossei, the adductor obliquus 

 and the adductor transversus hallucis, with a cutaneous branch 

 to the plantar aspect of the contiguous sides of the fourth and 

 fifth digits and the outer side of the little toe. 



The interal plantar nerve gives branches to the abductor hal- 

 lucis, the flexor brevis digitorum, flexor brevis hallucis and the 

 two inner lumbricals, and a cutaneous supply to the plantar 

 aspect of the inner side of the great toe and the contiguous sides 

 of the first and second, second and third, third and fourth toes. 

 As these digital branches proceed forwards to supply the skin 

 covering the toes they pass between the heads of the metatarsal 

 bones, and as the outcome of the crowding together of the bones 

 by pressure of narrow boots, the nerves going to supply the 

 contiguous sides of the fourth and little toes may be caught 

 between the base of the first phalanx and the head of the 

 metatarsal bone of the little toe on the one hand, and the head 

 and neck of the metatarsal bone of the fourth toe on the other. 

 Pain may not only be experienced at the actual site of pressure, 

 but may radiate up nearly as high as the knee. 



162 



