The Posterior Limb. 



227 



includes the typical extensors and flexors of the foot, together with 

 the peronaei muscles, which individually are extensors and flexors, 

 but collectively have the relation of lateral tractors (Fig. 77) . 



A. Extensor group. Muscles occupying an anterior position 



on the leg and inserted on the dorsum of the foot, 

 (a) The extensor hallucis longus. Origin: Middle portion 



of the anteromedial surface of the tibia and from the medial 



condyle behind the 



tibial collateral lig- *"^" 



ament. Insertion: 



The tendon passes 



around the medial 



malleolus of the 



tibia and beneath 



the base of the sec- 

 ond (first functional) lcib^i- 



metatarsal, continu- 

 ing to its dorsal 



surface and uniting 



with the first tendon 



of the extensor digi- 



torum longus. 



The posterior tibial artery, 

 the continuation of the 

 great saphenous, ■ and the 

 tibial nerve accompany the 

 tendon in the malleolar 

 groove. 



(b) The tibialis an- 

 terior. Origin: 



Po3lenor 



Fig. 77. Transverse section of the proximal 

 portion of the leg: a.s.m., great saphenous 

 artery; a.s.p., small saphenous artery; a. p., 

 a.t.a., anterior tibial artery; b.f., biceps femoris 

 (insertion); e.d.l., extensor ■ digitorum longus; 

 e.h.1., extensor iiallucis longus; f., fibula; f.d.l., 

 flexor digitorum longus; g.l., and g.m., lateral and 

 medial heads of the gastrocnemius; gr., gracilis 

 (insertion tendon); n.s., greater saphenous nerve; 

 n.s.m., lesser saphenous nerve; n.t., tibial nerve; 

 pi., plantaris; s., soleus; t., tibia; t.a., tibialis 

 anterior; t.f.c, tensor fasciae cruris (insertion); 

 v.is., sciatic vein; v.s.m., great saphenous vein; 

 v.s.p., small saphenous vein; 1-4, the personaei (pri- 

 mus- guar tus) . 



Lateral condyle of 

 the tibia and corresponding surface of the tibial tuberosity. In- 

 sertion: Base of the second metatarsal. The tendon passes beneath 

 the obliquely placed crural ligament of the lower portion of the leg. 

 The muscle should be divided and its head reflected. 

 The anterior tibial artery and vein, and the peroneal nerve appear 

 on the anterior surface of the tibia at the lateral side of the crural liga- 

 ment. 



