260 



THE MUSCLES OF THE LOWER LIMB. 



The three inner tendons are each joined at the outer side, on the first phalanx, by a 

 tendon from the extensor brevis digitorum. All the four tendons are continued into 

 expansions, which are joined on the first phalanx by tendinous processes from the 

 lumbricales andlinterosseous muscles ; they divide into three parts, their middle fibres 

 being inserted into the second phalanx, while their lateral parts unite together and 



Fig. 255. MUSCLES OF THE LEG AND FOOT FROM BEFORE. 

 (Allen Thomson. ) 1 



1, tendon of rectus femoris ; 1 1 7 , infrapatellar tendon ; 2, vastus 

 internus ; 3, vastus externus ; 4, sartorius ; 5, ilio-tibial band of 

 fascia lata ; 6, inner head of gastrocnemius ; 7, inner part of soleus ; 

 8, tibialis anticus ; 8', its tendon near its insertion ; 9, extensor pro- 

 prius hallucis ; 9', its tendon ; 10, extensor longus digitorum ; 10', 

 lower band of the anterior annular ligament ; 11, peroneus longus ; 

 12, peroneus brevis ; 13, peroneus tertius ; 13', its tendon at its 

 insertion ; 14, origin of extensor brevis digitorum, the ' first head of 

 . which is seen passing to the great toe near the line from 9', 



are inserted on the third, in a manner exactly similar 

 to the arrangement of the extensor tendons of the 

 fingers (p. 231). 



Relations. It is in contact internally with the tibialis 

 anticus and extensor proprius hallucis, and externally with the 

 peronei muscles. It rests upon the external tuberosity of the 

 tibia, the anterior surface of the fibula, the lower end of the 

 tibia, the front of the ankle-joint, and the extensor brevis 

 digitorum. The anterior tibial nerve passes obliquely inwards 

 beneath its upper part. 



Varieties. This muscle varies considerably in the mode of 

 origin and the arrangement of its various tendons. The tendons 

 to the second and fifth toes may be found doubled, or extra slips 

 are given off from one or more tendons to their corresponding 

 metatarsal bones, or to the short extensor, or to one of the inter- 

 osseous muscles. A slip to the great toe from the innermost 

 tendon has also been met with. 



The peroneus tertius muscle arises below the ex* 

 tensor longus digitorum, from the lower third or more of 

 the anterior surface of the fibula, from the lower part of 

 the interosseous membrane, and from the intermuscular 

 septum which separates it on the outer side from the 

 peroneus brevis. Its tendon is inserted into the upper 

 surface of the base of the fifth metatarsal bone. 



13- 



Belations. It is placed to the outer side of the long ex- 

 tensor of the toes, with which it is united at its origin, and it 

 passes through the same compartment of the annular ligament 

 with that muscle. 



Varieties. The peroneus tertius is sometimes as large as 

 the extensor longus digitorum ; it frequently terminates partly 



or wholly on the fourth metatarsal bone ; and it is sometimes wanting. A slip to join the 

 extensor tendon of the little toe is seldom present (1*3 per cent., Gruber). The peroneus tertius 

 is a muscle peculiar to man. 



Nerves. All the muscles of the front of the leg are supplied by the anterior tibial nerve. 



EXTERNAL REGION. 



The peroneus longus muscle arises by a few fibres from the outer tuberosity 

 of the tibia, from the head and upper two-thirds of the external surface of the 



