SUPERFICIAL PLANTAR MUSCLES. 



289 



From the insertion, offsets of the tendon are prolonged forwards to all 

 the cuneiform bones, to the os cuboides, and to the bases of the second, 

 third, and fourth metatarsal bones ; and one thin process is directed back 

 to the sustentaculum tali. The tendon is covered by a synovial membrane 

 behind the malleolus. Close to its insertion, where it lies against the astra- 

 galus, it contains a sesamoid nbro-cartilage, which is occasionally converted 

 into bone. 



The tibialis posticus is concealed in great part by the aponeurosis prolonged over 

 it from the muscles on either side. Superiorly it is not covered by these muscles, 

 and supports the posterior tibial and peroneal vessels. 



SHORT PLANTAR MUSCLES. 



COMMON FLEXOR OF THE TOES. The flexor brevis digitorum, or flexor 

 perforatusj arises by a small pointed and tendinous attachment from the 

 inner part of the greater tuberosity of the calcaneum, from the deep sur- 

 face of the plantar fascia for about two inches forwards, and from the 

 intermuscular septum on each side. The muscle terminates in four slender 

 tendons, inserted into the second phalanx of each of the four outer toes. 

 Each tendon prior to its insertion divides and gives passage between its 

 parts to the tendon of the long flexor, in a manner precisely similar to the 

 arrangement of the tendons of the flexor sublimis and flexor profundus 

 muscles of the hand. 



This muscle lies between the abductor pollicis and abductor minimi digiti, and is 

 covered by the plantar fascia, which adheres very closely to the posterior part of its 

 surface, and gives origin there to some of its fibres ; it conceals the flexor accessorius, 

 with the tendons of the flexor longus digitorum, the lumbricales, and the plantar 

 vessels and nerves. 



Fig. 220. SUPERFICIAL PLANTAR MUSCLES, AS SEEN ON THE Fi g< 220. 



REMOVAL OF THE PLANTAR FASCIA. ~ 



1, abductor pollicis; 2, flexor brevis digitorum dividing into 

 four slips for the lesser toes : in the second, the sheath is 

 opened so as to show the tendon of the flexor brevis perforated 

 hy that of the flexor longus ; in the other three toes the trans- 

 verse and oblique crossing fibres of the sheath are shown ; 3, 

 strongest portion of the plantar aponeurosis left upon the 

 surface of the flexor brevis, near the os calcis ; 4, abductor 

 minimi digiti : the lumbricales muscles are also in part 

 shown. 



MUSCLES OF THE GREAT TOE. The abductor 

 pollicis pedis arises from the inner part of the larger 

 protuberance of the calcaneum, from the internal 

 annular ligament and the tendinous and fibrous struc- 

 tures on the inner border of the foot as far forwards 

 as the internal cuneiform bone, from the septum 

 between it and the flexor brevis digitorum, and from 

 the plantar fascia covering it. The fleshy fibres end 

 in a tendon, which, after uniting with the internal 

 head of the flexor brevis pollicis, is inserted into the 

 inner border of the base of the first phalanx of the 

 great toe. 



The flexor brevis pollicis pedis, single and pointed behind, but divided into 



u 



