LEG AND FOOT. 



Extensor Proprius Hallucis. Origin; middle three-fifths of 

 front of fibula; corresponding extent of interosseous mem- 

 brane. Course of tendon; under anterior annular ligament, in 

 a special synovial sheath under the lower part. Insertion ; base 

 of terminal phalanx of great toe. [380] 



Extensor Brevis Digitorum. Origin; impression on upper 

 surface of greater process of os calcis. Course ; it forms four 

 fleshy bellies which end in narrow tendons. Insertion; (three 

 outer tendons) expansion of Extensor longus digitorum on 

 dorsum of three middle toes; (innermost tendon) base of first 

 phalanx of great toe. [380] 



Outer Side of Leg. 



Peroneus Longus. Origin; upper two-thirds of outer sur- 

 face of fibula ; intermuscular septa on either side ; fascia over 

 it. Course of tendon; around external malleolus and across 

 outer side of os calcis, running under external annular ligament 

 in a common synovial sheath; then around border of cuboid, 

 developing a fibro-cartilage over the tubercle, a bursa interven- 

 ing ; then through peroneal groove on under surface of cuboid 

 and across foot, in a sheath derived from the inferior calcaneo- 

 cuboid ligaments. Insertion; internal cuneiform; base of first 

 metatarsal. [381] 



Peroneus Brevis. Origin; lower two-thirds of outer surface 

 of fibula ; intermuscular septum at anterior border. Course of 

 tendon; over back of external malleolus and across outer side 

 of os calcis, running under external annular ligament in same 

 synovial sheath as preceding. Insertion; base of fifth meta- 

 tarsal. [381] 



Back of Leg; Superficial Set. 



Gastrocnemius. Origin; (by two heads, inner and outer, 

 with a bursa under each) lateral surface of each femoral con- 

 dyle ; back of knee-joint capsule. Course ; two separate bellies. 



[295] 



