SOLE OF THE FOOT 397 



Flexor Digit! Quinti Brevis (O.T. Flexor Brevis Minimi 

 Digiti). The short flexor of the little toe is a single fleshy slip, 

 which springs from the base of the fifth metatarsal bone and 

 the sheath of the peronaeus longus tendon. It is inserted into 

 the lateral side of the base of the proximal phalanx of the 

 little toe. Its nerve of supply arises from the superficial 

 division of the lateral plantar nerve. It is a flexor of the 

 metatarso-phalangeal joint of the little toe. 



Dissection. The oblique head of the adductor hallucis, and 

 the flexor hallucis brevis, must now be detached from their origins 

 and thrown towards their insertions, in order that the entire 

 length of the plantar arterial arch, the deep division of the lateral 

 plantar nerve, and the termination of the dorsalis pedis artery 

 may be displayed. As the oblique head of the adductor hallucis 

 is raised the branch which is given to it by the deep division of 

 the lateral plantar nerve must be secured and retained. 



Arcus Plantaris. -- The plantar arterial arch is the 

 continuation of the lateral plantar artery across the sole 

 of the foot. It runs from the level of the base of the fifth 

 metatarsal bone to the base of the first interosseous space, 

 where it is joined by the terminal plantar portion of the 

 dorsalis pedis artery. The arch is deeply placed ; it rests 

 against the interosseous muscles, close to the proximal ends 

 of the metatarsal bones (Figs. 174, 175), and it is concealed 

 by the flexor tendons, the lumbrical muscles, and the oblique 

 head of the adductor hallucis. It is accompanied by the 

 deep division of the lateral plantar nerve and by two venae 

 comites. 



The branches which proceed from the arch are : 



1. Articular. 



2. Posterior perforating. 



3. Second, third, and fourth plantar metatarsal arteries. 



4. Plantar digital artery to the lateral side of the little toe. 



The articular branches arise from the concavity of the arch, 

 and run posteriorly to supply the tarsal joints. 



The posterior perforating branches are three in number. 

 They pass dorsally through the posterior ends of the lateral 

 three intermetatarsal spaces and between the heads of the 

 corresponding dorsal interosseous muscles. Each ends, on 

 the dorsum of the foot, by joining the corresponding dorsal 

 metatarsal artery. 



The second, third^ and fourth plantar metatarsal branches 



