CRURO-PEDAL MUSCLES 



487 



muscles, beneath the former of which it crosses, distally, to the tibial side of the 

 leg. Septa separate the flexor muscles from the tibialis. The tendons of the 

 three muscles pass behind the medial malleolus, held in place by the transverse 

 septum and the deep layer of the laciniate (internal annular) ligament. They lie 



Fig. 416. — The Deep Muscles of the Back of the Leg. 



Plantaris ■ 



Lateral head of gastrocnemius • 





Biceps- 



Medial head of gastrocnemius 



Tendon of semi-membranosus 



Peroneus longus- 



Flexor hallucis longus- 



Popliteus 



Tibialis posterior 



' Flexor digitorum longus 



Peroneus brevis< 



' Tibialis posterior 

 ■ Laciniate ligament 



■ Tendo Achillis 



in compartments divided by septa which descend to the tibia. The compart- 

 ment for the tibialis posterior is the most medial. It is partly overlapped by 

 that for the flexor digitorum. At the ankle the tendon of the tibialis passes 

 above, the tendon of the flexor digitorum medial to, and that of the flexor hallucis 

 below, the sustentaculum tall, each in a separate osteo-fibrous canal bounded 



