MUSCLES OP THE LEG. 



T65 



The plantaris arises fleshy from the ridge leading to the 

 external condyle, forms a short fleshy belly hid by the 

 gastrocnemius, which passes across and adheres to the 

 capsular ligament of the joint. It ends in a long, flat, 

 delicate tendon which emerges between the gastrocnemius 

 and soleus, and then descends along the inner edge of the 

 tendo-Achillis to be inserted into the posterior and inner 

 part of the os calcis. Function. To extend the foot. This 

 muscle is sometimes absent. 



The popliteus arises by a round tendon on the outer face 

 of the external condyle, behind the knee-joint, FIG. 253. 

 and forms a fleshy belly, which descends in- 

 ward to be inserted into the ridge below the 

 head of the tibia. A bursa is seen between 

 its tendon and the capsular ligament. 

 '.._ Function. To flex the leg and turn it in- 

 ward. 



The flexor longus or communis digitorum 

 pedis (Fig. 253) arises from the posterior 

 part of the tibia, below the popliteus, and 

 from the angle of the tibia, nearly to the 

 ankle joint. It ends in a tendon which runs 

 in a groove behind the internal malleolus, 

 being confined here by a strong ligamentous 

 band; it then passes along the sinuosity of 

 the os calcis to the sole of the foot, receiving 

 at this point an accessory tendon from the 

 flexor longus pollicis. It divides into four 

 tendons which pass through slits in the flexor 

 brevis, and are inserted into the base of the 

 third phalanx of the smaller toes. This mus- 



FIG. 253 represents the deep Muscles on the back of the Leg. ] Lower 

 portion of the femur. 2 Ligament of Winslow. 3 Tendon of semi-membra- 

 nosus. 4 Internal lateral ligament of the knee-joint. 5 External lateral 

 ligament of the same joint. 6 Popliteus muscle. 7 Flexor longus digitorum 

 pedis. 8 Tibialis posticus. 9 Flexor longus pollicis. 10 Peroneus longus. 

 11 Peroneus brevis. 12 Insertion of tendo-Achillis. 13 Tendons of flexor 

 longus and tibialis posticus. 



