428 



THE MUSCULAR SYSTEM. 



GASTROCNEMHJS 



SKMIMKM- 



BRANOSUS 



SOLEUS (flbular 

 origin) 



SOLEUS (tibial 

 origin) 



Popliteus ' 

 (insertion) 



Soleus 

 (origin) ' 



Tibialis 



posterior 



(origin) 



The Muscles on the Posterior Aspect of the Leg. 



The muscles on the back of the leg are divisible into two groups, superfick 



and deep. 



The superficial group comprises th 

 gastrocnemius and soleus (constituting tc 

 gether the triceps surse) and the plantarii 

 They form the prominence of the calf of th 

 MEDIAL HEAD OF leg. The gastrocnemius 

 pllTA C Ris MIUS i 8 superficial except at 



LATERAL HEAD OF its Origin, where the 



two bellies, forming the 

 boundaries of the pop- 

 liteal foSSa, are OVer- Semimem 



lapped by the tendons (i jE3SJ 

 of the hamstring mus- 

 cles. The soleus muscle 

 is partially concealed 

 by the gastrocnemius 

 and plantaris, and be- 

 comes superficial in 

 the distal part of the 

 leg on each side of the 

 common tendon (tendo 

 calcaneus). 



M. Gastrocnemius. 

 -The gastrocnemius 

 arises by two heads, 

 medial and lateral, by 

 means of strong ten- 

 dons which are pro- 

 longed over the surface 

 of the muscle. The 

 lateral head arises from 

 an impression on the 

 proximal and posterior 

 part of the lateral sur- 

 face of the lateral con- 

 dyle of the femur, and 

 from the distal end of 

 the lateral epicondylic 

 line ; while the medial 

 head arises from a 

 prominent rough mark 

 on the popliteal surface 

 of the femur, proximal 

 to the medial epicondyle 

 and posterior to the 

 adductor tubercle. 

 Each head has an ad- 

 ditional origin from 

 the back of the capsule 

 of the knee-joint. A 

 bursa lies deep to each FlG - 

 tendon of origin. 



Each fleshy belly 



of the muscle is inserted, separately, into a broad membranous tendon, prolongec 

 proximally on its deep surface for some distance. The medial head is the larger. 

 The tendo calcaneus is formed by the union of the two membranous insertion; 



FLEXOR DIGITORUM 

 LONG us 



FLEXOR HALLUCIS 



LONG US 



Flexor 

 digitorni 

 longus 

 (origin) 



PERON^US BREVIS 



Ligamentum lacini- 

 '"" atum 



TENDO CALCANEUS 



Peroneal retinaculum 



PIG. 383. THE DBEP MUSCLES ON THE 

 BACK OF THE RIGHT LEG. 



384. MUSCLE - ATTACI 



MENTS TO THE POSTERIC 



SURFACE OF THE RIGHT TIBL 



