286 INFERIOR EXTREMITY 



narrow tendon, within the capsule of the knee-joint, from the 

 front of the popliteal groove on the lateral surface of the 

 lateral condyle of the femur. The fleshy fibres are directed 

 medially and distally, and spread out to obtain insertion 

 into the posterior surface of the tibia above the linea poplitea, 

 and also into the aponeurosis which covers the muscle. 



The nerve to the popliteus has already been seen to arise 

 from the tibial nerve. It can now be seen hooking round the 

 distal margin of the muscle to reach its anterior surface. 



M. Flexor Hallucis Longus. The flexor hallucis longus is 

 a powerful muscle which arises from the posterior surface of 

 the fibula, distal to the origin of the soleus, from the posterior 

 peroneal septum, and from the surface of the aponeurosis 

 covering the tibialis posterior. Its tendon occupies a deep 

 groove on the posterior border of the talus, and turns 

 forwards under cover of the ligamentum laciniatum to gain 

 the sole of the foot. The flexor hallucis longus is supplied 

 by the tibial nerve. 



M. Flexor Digitonun Longus. The flexor digitorum longus 

 arises from the posterior surface of the body of the tibia, distal to 

 the popliteus, and medial to the vertical ridge which descends 

 from the linea poplitea. It also derives fibres from the surface 

 of the aponeurosis which covers the tibialis posterior. After 

 crossing the lower part of the tibialis posterior, its tendon 

 grooves the back of the medial malleolus on the lateral side 

 of the tendon of that muscle. It is continued under cover 

 of the ligament laciniatum into the sole of the foot. The 

 flexor digitorum longus is supplied by the tibial nerve. 



M. Tibialis Posterior (O.T. Tibialis Posticus). This 

 muscle takes origin from the posterior surface of the inter- 

 osseous membrane, from the posterior part of the medial 

 surface of the body of the fibula, from the posterior surface 

 of the body of the tibia on the lateral side of the flexor 

 digitorum longus, and from the aponeurosis which covers 

 it. In Fig. 95, p. 262, the compartment which it occupies 

 is shown in a diagrammatic manner, and the surfaces from 

 which it takes origin are indicated. Towards the distal 

 part of the leg the tibialis posterior inclines medially, 

 under cover of the flexor digitorum longus, and its strong 

 flattened tendon grooves the back of the medial malleolus 

 to the medial side of the tendon of that muscle. Proceed- 

 ing under cover of the ligamentum laciniatum, its tendon is 



