GASTEOCXEMIUS MUSCLE. 



249 



The gastrocnemius muscle arises by two thick tendinous heads from 

 the condyles of the femur, and ends below in the tendo Achillis. The 



Fig. 193 



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Fig. 193. — SuPKRFiciAL Muscles op the Leg, seen 

 FROM BEHIND (after Bourgery). | 



1, lower outer part of the vastus muscle ; 2, 

 liceps flexor cruris ; 3, semitendinosus ; 4, semi- 

 membranosus ; 5, gracilis ; 6, sartorius ; 7, outer, and 

 8, inner head of the gastrocnemius ; 9, placed in 

 the popliteal space, points to the plantaris ; 9', its 

 thin tendon inside the tendo Achillis ; 10, the fibres 

 of the soleus descending to the flat tendon, which 

 joining with that of the gastrocnemius, forms + + 

 the tendo AchUlis ; 11, peroneus longus ; 12, peroneua 

 brevis ; 13, flexor longus digitorum ; 14, tibialis 

 posticus ; 15, is placed on the lower i^art of the 

 fibula, and points to the lower filjres of the flexor 

 longus pollicis, the tendon of which is seen descending 

 over the tibia at 15'. 



outer tendon of origin is attached to a 

 depression on the outer side of the ex- 

 ternal condyle, above tlie groove for the 

 popliteas muscle^ and also to the upper and 

 back part of the same condyle. The inner m/ 



tendon is attached in a horizontal line to an 

 impression above the back part of the in- 

 ternal condyle, and to a small part of the 

 ridge running to the linea aspera. The 

 muscular fibres descending from the two 

 heads remain separated by a vertical gro^^•e 

 on the surface, but those next the middle 

 meet at an angle on a tendinous structiive 

 below. The fibres of the superior tendons 

 spread out upon the surface of the mus- 

 cle ; the inferior tendon lies on the dcc]^ 

 surflice of the muscular mass, and is con 

 tinned upwards in a thin ajjoneurosis witl 

 parallel fibres, which glide against the 

 soleus : between the superficial tendon of 

 eacli head and the deep common tendon, wn-*" i 



the greater number of the muscular fibres I IV mil J^ 



run obliquely downwards and forwards. 

 The lower edge of each muscular part 

 presents a convexity downwards ; the inner I^Wl 



descending farthest. A synovial bursa, C 



usually communicating with the knee-joint, 



lies beneath the inner head of origin, and separates it from the tendon 

 of the semimembranosus muscle. In the outer head a sesamoid fibro- 

 cartilage is sometimes met with over the outer condyle of the femur, 

 "which is occasionally found ossified. 



Hclatlonst. — The heads of the gastrocnemius muscle fonn the inferior boundaries 

 of the popliteal sjjace, and are placed between the hamstring muscles : the pero- 

 neal nerve is lodged between the external head and the biceps. The gastrocne- 

 mius conceals the i^opliteus. plantaris and soleus muscles, with the popliteal 



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