SOLE OF THE FOOT 



299 



Calcanei 



all the tendons of the flexor digitorum longus into connection with the 

 tendon of the flexor hallucis longus. 



The musculus quadratus plantce which is inserted into the 

 tendon of the long flexor of the toes, and also the four 

 lumbrical muscles which arise from the flexor tendons, can 

 now be distinguished. Note the position of the long 

 plantar ligament between 

 the two heads of origin of 

 the quadratus plantae. 



Fibrous Flexor Sheaths. 

 Before tracing the flexor 

 tendons forwards on the 

 toes, it is necessary to ex- 

 amine the sheaths which 

 retain them upon the 

 plantar aspect of the 

 phalanges. In their con- 

 struction these fibrous 

 sheaths are precisely simi- 

 lar to the corresponding 

 sheaths of the fingers. 

 They are not so strongly 

 marked, but they present 

 the same thickenings over 

 the shafts of the phalanges 

 and the same want of 

 strength opposite the inter- 

 phalangeal joints. They 



may now be opened in 



j , , 



Order that the enclosed 



tendons may be examined. 



A mucous sheath is present in each to facilitate the play 



of the flexor tendons within them (see p. 123). 



Insertions of the Flexor Tendons. Two tendons, one 

 from the flexor digitorum brevis and one from the flexor 

 digitorum longus, enter the flexor sheath of each of the 

 four lateral toes. Of these, the tendon of the former muscle 

 corresponds with a tendon of the flexor sublimis in the hand, 

 whilst the tendon of the flexor digitorum longus corresponds 

 with a tendon of the flexor profundus. Further, they are 

 inserted in exactly the same manner. The tendon of the 

 flexor brevis, which is the more superficial, divides into two 



Quadratus plantae 

 (O.T. 



Lumbricals " 



FIG. 109. Second layer of Muscles and 

 Tendons in the Sole of the Foot. 



