SURFACE MARKING OF LEG. 605 



SECTION IV. 



THE BACK OF THE LEG. 



Directions. Before the dissection of the leg is begun, the student should 

 make himself acquainted, as in the thigh, with the prominences of bone 

 and muscle on the surface, and with the markings which lead to the posi- 

 tion of the larger vessels. 



Prominences of bone. The bones of the leg can be traced beneath the 

 skin from the knee to the ankle-joint. On the inner side is the tibia, 

 which is subcutaneous in all its extent, and is limited in front and behind 

 by a sharp ridge : above, it presents in front a prominent tubercle into 

 which the ligament of the patella is inserted ; and below, it ends on the 

 inner side of the ankle in the internal malleolar projection. On the outer 

 side of the leg the lower half of the fibula may be felt with ease, but the 

 upper half with more difficulty in consequence of the prominence of the 

 muscles of the calf. The head of this bone may be recognized below the 

 knee ; and the lower end forms the eminence (malleolus) on the outer side 

 of the ankle joint. 



On the side of the ankle joint are the prominent malleoli ; and when 

 the joint is extended, the head of the astragalus can be felt below the 

 tibia. 



Muscles and vessels of the leg. On the back of the leg is the swell of 

 the calf: this is formed by the superficial muscles, and from it descends 

 the firm band of the tendo Achillis, by which those muscles are connected 

 with the heel. Between the tendon and the edge of the tibia, but nearest 

 the former, is placed the superficial part of the posterior tibial artery. In 

 front between the tibia and fibula are the flexor muscles of the foot and the 

 extensors of the toes, amongst which the anterior tibial artery lies deeply ; 

 the position of the vessel will be indicated by a line from the centre of the 

 ankle-joint to the inner side of the head of the fibula. 



Prominences of the foot. At the inner border of the foot, about an inch 

 in front of the internal malleolus, is the prominent scaphoid bone pointing 

 out the spot at which an amputation (Chopart's) is practised; whilst one 

 inch and a half farther forwards is a slight depression marking the articu- 

 lation between the internal cuneiform and the metatarsal bone of the great 

 toe. About the centre of the outer border of the foot is the eminence of 

 the tarsal end of the fifth metatarsal bone. A line over the dorsum of the 

 foot, from the centre of the ankle joint to the interval between the inner 

 two toes, will lie over the position of the main artery. 



Position. For the dissection of the back of the leg, the limb is to be 

 placed on its front, with the foot over the side of the dissecting-table ; and 

 the muscles of the calf are to be put on the stretch by fastening the foot. 



Dissection. For the. removal of the skin, one cut may be made along 

 the middle of the leg to the sole of the foot, where a transverse incision is 

 to be carried over the heel. The two resulting flaps of skin may be raised, 

 the outer one as far as the fibula, and the other as far as the inner margin 

 of the tibia. 



In the fat the cutaneous nerves and vessels are to be followed. On the 

 inner side, close to the tibia, is the internal saphenous vein with the nerve 

 of the same name, together with twigs of the internal cutaneous near the 



