246 



MUSCLES OF THE LOWER LIMB. 



The extensor longus digitoruni pedis arises from the external 

 tuberosity of the tibia ; from the head and the anterior narrowed part 

 of the inner smface of the fibula in front of 

 Fig. 191. the interosseus membrane, for about three- 



fourths of its length ; from a small part of 

 the interosseus ligament at its upper part ; 

 also from the aponeurotic septa intervening 

 between it and the muscles on each side, and 

 from the iascia of the leg. The tendon 

 divides into four slips, -which descend through 

 the lower part of the annular ligament, iu 

 the same sheath as the peroneus tertius, and 

 on the dorsum of the foot pass respectively 

 Hi \ . // to the four outer toes. The three inner 



tendons are each joined at the outer side, 

 on the first phalanx, by a tendon from the 

 extensor brevis digitoriuu. All the four ten- 

 dons are continued into expansions, which 

 are joined on the first phalanx by tendinous 

 jDrocesses from the lumbricales and interossei 

 muscles ; they divide into three parts, their 

 middle fibres being inserted into the second 

 phalanx, \^'hile their lateral parts unite to- 

 gether and are inserted on the third^ in a 

 manner exactly similar to the arrangement 

 of the extensor tendons of the fingers. 



/y 



\ 





Fig. 191. — Muscles op the Leg and Foot from 



BEFORE. (A. T. ) i 



1, teiulon of the rectus femoris ; 1', ligamentum pa- 

 tellre ; '2, vastus exteruiis ; 3, vastus interniis ; 4, sar- 

 toi'ius ; 5, fascia lata cut uear the place of its insertion 

 at the knee ; 6, inner head of the gastrocnemius ; 7, 

 inner pai-t of the sole us ; 8, tibialis anticus ; 8', its 

 tendon near the insertion ; 9, extensor longus pollicis ; 

 i)', its tendon ; 10, extensor communis digitorum longus ; 

 10', anterior annular ligament ; 11, jjeroneus longus; 

 I'l, peroneus brevis ; 13, x^eroneus tertius ; 13', its 

 tendon at its insertion ; 1 i, origin of the extensor com- 

 munis digitorum brevis, the first head of which is seen, 

 iwssing to the great toe near the line from 9'. 



Rrlaiionx. — It is in contact internally yv\t\\ the 

 tibialis anticns and extensor proprius pollicis, and 

 externally with the jieronei muscles. It rests 

 upon the external tuberosity of the tibia, the an- 

 terior 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 oblicpaely beneath its upper 



part. 



T7,/.,V'f/r.f.— This muscle varies considerably in the mode and place of insertion 

 of its various tendons. The tendons to the second and fifth toes may be found 

 doul)led, or extra slips are frequently given off from one or more tendons to 

 their corresponding metatarsal bones or to the short extensor, or to one ot 

 the interossei muscles. 



The peroneus tertius muscle arises below the exiensoi longutj 



