SOLE OF THE FOOT 383 



Dissection. Themedial calcanean nerves, which have already 

 been found piercing the ligamentum laciniatum, should be traced 

 to their distribution. They supply the skin of the sole in the 

 neighbourhood of the heel, and are accompanied by ramifications 

 of the medial calcanean branches of the posterior tibial and 

 lateral plantar arteries. 



The superficial fascia may now be removed. Divide it along 

 the middle line of the sole, and turn it laterally and medially, 

 cleaning at the same time the plantar aponeurosis. As the 

 dissector approaches the lateral and medial margins of the foot 

 respectively, he will note, on each side, a furrow ; the furrows 

 extend forwards at the sides of the intermediate part of the plantar 

 aponeurosis. Along the furrows a number of blood-vessels and 

 some nerves will be seen piercing the deep fascia in order to 

 reach the skin. Towards the intervals between the heads of the 

 metatarsal bones the metatarsal arteries and the plantar digital 

 nerves are unprotected by the aponeurosis, and the dissector must 

 proceed cautiously. The nerves and vessels which go to the 

 medial side of the great toe and to the fibular side of the little 

 toe are especially liable to injury, as they perforate the aponeu- 

 rosis farther back than the others. A band of transverse fibres, 

 which crosses the roots of the toes and lies over the digital vessels 

 and nerves, should be noticed. It is the superficial transverse 

 ligament of the toes, and is closely connected with the skin where 

 that forms the cutaneous webs between the toes. By forcibly 

 separating the toes its connections will become evident. When 

 the relations of the ligament have been studied it may be removed. 



Aponeurosis Plantaris (O.T. Plantar Fascia). The plantar 

 aponeurosis, which is now brought into view, consists of three 

 portions (a) a medial, () an intermediate, and (c) a lateral 

 part. The subdivision is indicated by a difference in the 

 density of the three parts and by two shallow furrows which 

 traverse the foot in a longitudinal direction, one upon each side 

 of the strong intermediate portion of the aponeurosis. Each 

 of the three portions is in relation to a subjacent muscle. 

 The intermediate portion covers the flexor digitorum brevis ; 

 the lateral part clothes the abductor digiti quinti ; and the 

 medial part covers the abductor hallucis. 



The intermediate portion of the plantar aponeurosis stands 

 out in marked contrast to the lateral and medial portions 

 in point of strength and density. Posteriorly, where it 

 is attached to the medial process of the calcaneus, it is 

 narrow, but it expands as it passes forwards, and, near the 

 heads of the metatarsal bones, splits into five processes, 

 which are bound together by transverse fibres. In the 

 intervals between the digital slips the metatarsal vessels, the 

 digital nerves, and the lumbrical muscles appear. Trace 

 the processes forwards. One goes to the root of each toe ; 



