1 68 TOPOGRAPHIC AND APPLIED ANATOMY. 



nerve for all of the flexor muscles, supplies the heads of the gastrocnemius and also the soleus 

 in the popliteal space (Fig. 83) and runs downward to the outer side of the posterior tibial artery 

 beneath the deep layer of the crural fascia. At the internal malleolus (Fig. 87) the nerve is 

 deeper than the artery and closer to the tendo Achillis. Before entering the sole of the foot it 

 divides into the internal and external plantar nerves. 



THE FOOT. 



Upon the dorsal surface of the foot may be seen tne subcutaneous venous plexus, giving 

 origin to the short saphenous vein (accompanied by the short saphenous nerve) behind the ex- 

 ternal malleolus, and to the long saphenous vein (accompanied by the terminal ramifications of 

 the long saphenous nerve) in front of the internal malleolus. These structures are situated in a 

 loose connective tissue, the character of which favors the occurrence of edema. If the foot is 

 strongly flexed dorsally, the tendon of the extensor longus hallucis, running to the great toe, springs 

 into prominence. To the inner side of this structure may be felt the strong tendon 0} the tibialis 

 anticus, on its way to the inner margin of the sole, the tendons of the extensor longus digitorum are 

 also made prominent (Fig. 85). In dorsal flexion the tense extensor brevis digitorum is also pal- 

 pable. In the middle of the dorsum of the foot to the outer side of the tendon of the extensor 

 longus hallucis may be felt the pulsations of the superficial dorsalis pedis artery. The tendons of the 

 peronei, though less prominent, may also be distinctly palpated beneath the external malleolus 

 during dorsal flexion. In the sitting posture with the foot resting flat upon the floor, the tip of 

 the finger may be placed in a depression upon the dorsum of the foot midway between the lower 

 extremities of the malleoli, and in this depression the tendons may be made to glide beneath the 

 finger. Just above this depression may be felt the lower end of the tibia and below it the 

 astragalus; it consequently marks the highest level of the ankle-joint. In this situation swelling 

 and fluctuation may occasionally be observed in inflammations of the articulation. At the inner 

 margin of the sole the tuberosity of the scaphoid bone may be felt without difficulty, below and 

 in front of the lower end of the internal malleolus; immediately behind this point, Choparfs 

 articulation (see page 170) may be opened. At the outer margin of the sole, opposite to the 

 scaphoid tubercle but somewhat in front of it, may be felt the tuberosity of the fifth metatarsal 

 bone, which is just in front of Lis franc's articulation (see page 170). Further anteriorly the 

 metatarsal and phalangeal bones may be palpated upon both sides of the foot ; the heads of the 

 metatarsal bones indicate the location of the metatarso phalangeal articulations. In plantar 

 flexion the heads of the phalanges may be felt upon the dorsal surface of the toes; they mark 

 the situation of the inter phalangeal joints. 



The dorsalis pedis artery (Fig. 85), the continuation of the anterior tibial, passes from the 

 anterior annular ligament along the dorsal surface of the foot in the first interosseous space. It 

 runs anteriorly from a point midway between the two malleoli and divides at the bases of the 

 first and second metatarsal bones into a larger branch, the plantar digital (ramus plantaris pro- 

 fundus}, passing between the first and second metatarsal bones to the plantar arch, and a smaller 

 branch, the dorsalis hallucis (A. metatarsea dorsalis I], running forward to the web between the 

 great and the second toes. To the outer side, the dorsalis pedis gives off the tarsal artery (A. 



