THE LEG 469 



on all sides, and its palpation is by no means easy. The outline 

 of the bone can best be made out along the posterior intermuscular 

 septum of the leg, which corresponds to a line drawn from the 

 posterior part of the head of the fibula to the posterior border 

 of the lateral malleolus. 



When the ankle is actively dorsi-flexed, the muscular belly 

 of the tibialis anterior forms a prominent elevation on the 

 anterior aspect of the leg, and its tendon can be traced distally 

 and medially across the front of the ankle-joint (p. 479). The 

 flexors of the ankle and extensors of the toes are separated 

 from the peroneal muscles, which act as evertors of the foot, 

 by the anterior intermuscular septum of the leg. This septum 

 corresponds to a line drawn from the anterior aspect of the 

 fibular head to the anterior margin of the lateral malleolus. In 

 eversion of the foot the peroneal muscles form a surface elevation 

 on the lateral aspect of the leg immediately behind the line of 

 the septum. This elevation is limited posteriorly by a 

 longitudinal furrow, which marks the position of the posterior 

 intermuscular septum and separates the peroneal muscles from 

 the muscles of the calf. 



The lateral margin of the soleus is rendered prominent when 

 the subject stands on tip-toe. It forms a narrow elevation 

 behind the posterior intermuscular septum, and it disappears 

 proximally under cover of the gastrocnemius. 



The common peroneal nerve can be rolled against the bone, as 

 it lies first behind the head and then lateral to the neck of the 

 fibula. Its superficial position and its close relationship to the 

 bone render the nerve liable to injury from bruising or following 

 fractures of the fibular neck. It is occasionally divided in 

 bullet and scythe wounds. 



The Deep Fascia of the Leg. The deep fascia is entirely 

 absent over the medial surface of the tibia, and it forms a 

 relatively thin sheet over the posterior aspect of the leg. It 

 is more strongly developed over the lateral and anterior aspects, 

 and is specially strong over the proximal part of the tibialis 

 anterior. The anterior and the posterior intermuscular septa 

 attach its deep surface to the corresponding borders of the fibula. 

 In the region of the ankle-joint the deep fascia is strengthened 

 to form ligamentous bands which retain the various tendons in 

 position. 



The transverse ligament stretches between the anterior borders 

 of the tibia and fibula immediately proximal to the malleoli. 



30 a 



