222 HANDBOOK OF ANATOMY 



tubercle of the tibia ; in the upper two-thirds of its course it lies 

 on the interosseous membrane ; in its lower third it lies on the 

 front of the tibia and terminates in front of the ankle-joint mid- 

 way between the two malleoli. 



The short saphenous vein, which lies a little to the outer side of 

 the tendo Achillis, gradually reaches the middle of the calf and 

 ascends to the popliteal space. The internal saphenous vein and 

 nerve lie along the inner border of the tibia. 



The course of the posterior tibial artery is indicated by a line 

 drawn from the lower angle of the popliteal space to a point 

 midway between the internal malleolus and the tendo Achillis. 

 The peroneal artery, beginning three inches below the head of 

 the fibula, is indicated by a line from that point to one midway 

 between the external malleolus and the tendo Achillis. 



The Foot. 



The tip of the external malleolus is J inch lower and f inch 

 posterior to that of the internal 'malleolus. The line of the ankle- 

 joint can be felt on either side of the extensor tendons, and when 

 the foot is extended a prominence is formed by the anterior part 

 of the superior articular surface of the astragalus below the 

 anterior border of the lower end of the tibia. 



A finger's breadth below the tip of the internal malleolus is 

 the sustentaculum tali ; 1J inches in front of the latter is the 

 tubercle of the scaphoid ; close above it is the tendon of tibialis 

 posticus. 



A finger's breadth below the tip of the external malleolus is 

 the peroneal tubercle of the os calcis, a guide to the two peronei 

 tendons. 



The line of the tarso-metatarsal joints extends nearly 1 inch 

 further forwards on the inner than on the outer surface of 

 the foot. 



The metatarso-phalangeal joints are situated one inch behind 

 the web of the toes. 



Crossing the front of the ankle-joint, from within outwards, 

 are the tendons of tibialis anticus, extensor longushallucis, extensor 

 longus digitorum } and peroneus tertius. The extensor brevis digi- 

 torum forms a fleshy pad over the calcaneo-cuboid joint. The 



