354 



REGIONS OF THE FOOT. 



to a considerable degree. The sensibility of 

 this part of the integuments is not at all in 

 relation to its apparent want of delicacy in 

 structure ; no part of the body possesses a 

 covering more acutely sensitive. The effects 

 of pricking, of titillation, of cold or heat 

 applied to the sole of the foot, exemplify this. 

 Its sympathies also are as remarkable for their 

 liveliness as for their extent. Not even the 

 arm-pits or sides of the ribs are at all equal to 

 it in this respect. The bladder, the urethra, 

 the stomach and intestines, in fact almost all the 

 mucous membranes, together with the whole 

 voluntary system of nerves, and through them 

 the whole system of voluntary muscles, may 

 be said especially to sympathize with and to 

 be influenced by this one part. Of this no 

 one can doubt when we see the effects of 

 sudden cold applied to it in relaxing spasm of 

 the urethra or bowels, in checking vomiting, 

 or in rousing the whole nervous and muscular 

 system during fainting, &c. The effect also of 

 hot applications of stimulants and irritants 

 applied to this part familiarly illustrate its ex- 

 tensive sympathies. The most sensitive part 

 of the sole is the hollow, that part where the 

 cuticle is least dense. 



When the cutis is removed, we expose a 

 stratum of cellular tissue remarkable for its 

 density and toughness, and for the granular 

 fat with which its cells are rilled ; it lies imme- 

 diately under the true skin, and over the 

 plantar fascia. We may here observe that a 

 similar integument, and the same kind of cel- 

 lular web under it, is spread over the heel, 

 and, from the peculiarity of its texture, is 

 probably more likely to inflame under the 

 effects of pressure than the skin of other parts 

 of the body ; at any rate, it very frequently 

 does inflame, and even slough, when long 

 subjected to pressure ; and inattention to this 

 point is often the source of great misery in 

 the treatment of fractures and dislocations of 

 the lower extremity. The heel resting upon 

 some hard portion of the apparatus often so 

 torments the patient as to be a serious impedi- 

 ment to the successful treatment of the case. 



The fascia plantaris demands our particular 

 attention. It is a strong tendinous structure 

 forming a covering to the muscles and impor- 

 tant structures of the sole. It is very thick 

 and dense at its posterior part, and becomes 

 thinner, though still of the same consistence, 

 at the anterior part. The cellular web just 

 mentioned strongly adheres to it externally, 

 while the muscles which it covers are not only 

 adherent to its inner side, but many of their 

 fibres arise directly from it. It not only forms 

 a layer of separation between these muscles 

 and the more external parts, but it sends pro- 

 cesses of a similar tendinous structure between 

 the principal muscles, which also afford origin 

 to many of their fibres. It divides itself into 

 three portions, one covering each of the three 

 principal groups of muscles found here. These 

 three portions are, however, united behind 

 where they arise in common from the under 

 projecting part of the os ealcis, while ante- 

 riorly the layer becomes quite incomplete from 



the subdivision into five slips, each of these 

 again splitting to pass to be fixed into each 

 side of the heads of the metatarsal bones. The 

 situation, structure, and connexions of this 

 fascia, of the dense stratum of cellular tissue, 

 and of the peculiar skin covering this, are 

 highly important to the surgeon. The know- 

 ledge of these points teaches why phlegmonous 

 inflammation must be difficult of treatment, 

 and often dangerous in its results, whether it 

 occurs immediately under the skin or under 

 the fascia, but particularly in the latter situa- 

 tion, the dense unyielding structure of which 

 prevents the swelling from pressing outward, 

 thus greatly aggravating the pain and irritation, 

 and when matter has formed, equally prevents 

 its pointing outwards, and calls for the early 

 application of the lancet to give it free vent, 

 and thus prevent its spreading along the foot. 

 The structure of the parts just described is, as 

 far as it goes, an objection to the partial ampu- 

 tation of the foot recommended by Chopart, 

 wherein the flap is formed from these parts in 

 the sole, together with the muscles and tendons 

 found there. But this objection is by no 

 means fatal to operations upon these parts, 

 which have often been successfully performed, 

 and when they are so, often give a limb much 

 more useful than a wooden one. 



We now come to the deep-seated parts of 

 the foot. These consist, 1. of the muscles 

 and tendons; 2. of veins and arteries; 3. of 

 nerves ; 4. of absorbents. The muscles and 

 tendons compose three principal groups des- 

 tined to accomplish the movements of the 

 great toe, of the three middle toes, and of the 

 little toe, and according to their destination 

 and use, so is their situation in the sole. On 

 the inner side the abductor, the adductor, the 

 flexor brevis, and tendon of the flexor longus 

 pollicis form a pretty considerable mass, and 

 have a separate slip of the fascia plantaris 

 lying under them, in contact with the most 

 superficial of them, viz. the abductor. On the 

 outer or fibular side of the sole, a similar mass 

 of muscles, but smaller, lie underneath the 

 metatarsal bone of the little toe, composed 

 also of an abductor and a short flexor, while 

 one slip both from the long and short common 

 flexors joins them anteriorly. The space be- 

 tween these two masses of muscles is occupied, 

 most superficially, and immediately in contact 

 with the plantar fascia, by the flexor brevis 

 digitorum, next by the tendons of the flexor 

 longus digitorum, accompanied by their acces- 

 sories ; posteriorly, the accessories or massa 

 carnea Jacobi Sylvii ; and anteriorly, the lum- 

 bricales, while deeper still than all there are 

 the interossei interni. 



Amidst this number of small muscles, the 

 plantar arteries take their course in the follow- 

 ing manner. The posterior tibial artery, as 

 we have elsewhere seen (vide ANKLE-JOINT, 

 REGIONS OF), passing down behind the inner 

 malleolus, gets into the hollow of the os 

 ealcis, lying pretty close to this bone, and 

 covered only by the integuments, cellular 

 tissue, and fascia. It now passes between the 

 origins of the adductor pollicis, and in doing 



