154 ANATOMY IS A NUTSHELL. 



Origin. — (Plato L.) — (1) Back part of head of fibula ; (2) upper 'hird of 



rior surface of shaft of fibula; (3) oblique line of tibia; (4) middle third of 

 internal border of tibia; (5) tendinous arch between the tibial and fibular ori- 

 gin-, beneath which the popliteal vessels and internal popliteal nerve pass. 



[nsertion.— (Plate LII.) — Os calcis by tendo Achillis. 



A* HON.— Steadies leg on foot : prevents body from falling. 



N era i. Suppli . Internal popliteal and posterior tibial. 



'u.oDi) Supply. — Popliteal. 



Plantaris.- Description. — (Plate LXXVII.) — This muscle is sometimes 

 absent and again it may be double. It has the longest tendon of any muscle 

 in the body. It takes its name because it is sometimes inserted into the plantar 

 fascia. The muscular part of the Plantaris is a small fusiform belly about three 

 or four inches in length. It is situated between the Gastrocnemius and Soleus 

 and the tendon finally running along the inner side of the tendo Achillis. It 

 may be lost in the fascia of the leg or the internal annular ligaments. 



Origin. — (Plate XLVIII.) — From the lower part of outer prolongation of 

 linea aspera and from posterior ligament of knee-joint. 



Insertion. — (Plate LII.) — Os calcis with tendo Achillis. 



Action. — Flexes leu- and extends foot. 



Nerve Supply. — Internal popliteal. 



Blood Supply. — Popliteal. 



LESSON XLI. 



Popliteus.— Description. — (Plate LXXIX.) — This muscle forms part of 

 the popliteal space. It is a thin flat triangular muscle, and is different from 

 nio-t other muscles in that its origin is smaller than its insertion. The internal 

 popliteal nerve and the popliteal vessels cross the superficial surface of this 

 muscle. 



Origin. — (Plate XLIX.) — Deep depression on outer condyle of femur and 

 posterior ligament of knee. 



Insertion.- (Plate L.) — Inner two-thirds of triangular surface above 

 oblique line on posterior surface of shaft of tibia ami tendinous expansion cover- 

 ing surface of muscle. 



Action. Flexes and rotates leg inward. 



Xi:i;\ i; Supply.- fourth and fifth lumbar and first sacral through internal 

 popliteal. 



Blood Suppli . - Popliteal. 



Flexor longua hallucis. — Description. — (Plate LXXIX.) — This musch/is 

 on the fibular side of the lei: although it passes to the great toe. Its tendon 

 occupies most all of the posterior surface of the muscle, then it passes through 

 three grooves in three different bono, first one is on the posterior surface of 

 the lower end of the tibia; the second one is on the posterior surface of the 

 astragalus; and the third one is beneath the sustentaculum tali of the os calcis. 

 The tendon finally passes between the two heads of the Flexor brevis hallucis 

 to its insertion. 



