FLEXOE MUSCLES OP THE FOOT. 



253 



It is covered at the upper part by the soleus and inferiorly by the aponeurosis of 

 the leg. Upon it also lie the posterior tibial vessels and nerve. 



Var'iiiirs. — A second head of origia has not unfrequcntly been found. This 

 may arise from the outer tuberosity of the tibia, or from the fibula, or from the 

 fascia of the leg. This second head has been seen joining the accessorius or even 

 replacing it (Otto). Gies descril^es an accessory slip from the tibialis anticus, 

 which joined the flexor digitorum at the ankle. A.fr-rnrdigitisccundi2}rom'his 

 was foimd by Bahnsen, arising from the back of the tibia. 



Fig. 196. — Second Later op Plantar Muscles. Fig. 196. 



1, tendon of the flexor longus polHcis mviscle, emerging 



behind from its sheath below the sustentaculum tali, and 



passing deeper than, 2, the tendons of the deep common flexor ; 



3, two lieads of the flexor accessorius ; 4, tlie four lumbricales ; 



5, tendon of the flexor brevis cut short and seen splitting to 

 allow the passage through it of the tendon of the long flexor ; 



6, flexor brevis pollicis ; 7, flexor brevis minimi digiti ; there 

 is also represented on tlie outer side of the foot the tendon of 

 the peroneus longus -winding round the cuboid bone. 



Intimately connected witli the tendon of the 

 flexor longus digitorum are the flexor accessorius 

 and the lumbricales muscles, which, although they 

 occupy the foot, ma y be most conveniently de- 

 scribed in this place. 



The flexor accessorius arises by two heads, 

 the internal and larger of which is fleshy, and is 

 attached to the inner surface of the calcaneum, 

 while the external, flat, narrow, and tendinous, 

 is attached to the plantar surface of the cal- 

 caneum a little in front of the external tubercle, 

 and to the ligamentum longum plantge. Thoae 

 origins united form a muscular mass which is inserted into the 

 external border and upper and lower surfaces of the tendon of the flexor 

 longus digitorum. 



The lumbricales muscles, four in numl)er, arise from the tendons of 

 the flexor longus digitorum at their point of division, each being, Avith 

 the exception of the most internal, attached to two tendons. They 

 pass forward to the inner sides of the four outer toes, each muscle ending- 

 in a tendon, Avhich is inserted into the expansion of tlie extensor tendon 

 on the dorsum of the first phalanx of the toe. 



Ii('latio7is. — In the sole of the foot the tendons of the flexor longus digitorum, 

 together with the flexor accessorius and the lumbricales, are covered below by 

 the flexor brevis digitorum ; the plantar nerves and hinder part of the external 

 plantar artery being placed between. These tendons, with their additional mus- 

 cles, conceal the adductor pollicis. the tendon of the flexor longus pollicis, 

 the transversus pedis, the interossei muscles, and the plantar arterial arch. 



The flexor longus pollicis pedis, or flexor hallucis muscle, arises 

 from the lower two-thirds of the posterior surface of the fibula, except 

 for an inch at its lowest part ; from the intermuscular septum between 

 it and the peronei ; and from the aponeurosis common to it and the 

 flexor longus digitorum, which covers the tibialis posticus. The mus- 

 cular fibres, passing obliquely backwards and downAvards, end in a 

 tendon on the posterior surface of the muscle. This tendon traverses 

 a groove on the lower end of the tibia, at the back of the astragalus and 



