tendon, therefore the whole separation, after the 
_ division, is performed by the moving of the 
_ dower part. 
The powerful muscles, now described, are 
never known to be ruptured themselves, the 
tendon, as we have seen, yielding first, but 
partial rupture of their fibres is not very 
uncommon, and is indicated by the same pain- 
symptoms as were alluded to in speaking 
of the anterior muscles. It is worth remarking, 
on the great power of these muscles, that, great 
is is the force required, to elevate the whole 
dy, by acting upon the heel, yet the muscles 
the calf are not nearly so soon fatigued in 
alking as those on the front of the leg, whose 
Tabour is merely the elevation of the foot and 
toes, and of this every one must be sensible 
Le fter unusually long exercise on foot. 
_ Between the gastrocnemius and the soleus 
is the plantaris tendon, a long slender slip, 
which, after crossing between the muscles, runs 
| onthe inner side of the tendo Achillis, to its 
nsertion. The belly of this little muscle is 
under the outer head of the gastrocnemius, 
slose to the origin of which it arises. Authors 
scribe the symptoms attendant upon rupture 
of this tendon, Put the diagnosis of injury to 
o small and deep-seated an organ must be so 
ncertain, that we should be much more in- 
clined to refer them to an injury of some of 
he fibres of the great muscles of the calf, es- 
pecially when we compare the power of the 
plantaris with that of its tendon, the passive 
ength of the latter appearing greatly superior 
0 the active force of the former.* Between 
he lower part of the tendo Achillis and the 
endons of the deep layer of muscles, there is 
considerable layer of cellular tissue, con- 
aining fat, and this is often the seat of trouble- 
ome chronic inflammation ; and if suppuration 
ollows, the abscess is often very difficult of 
ealing, from the constant movement of the 
endon, and the result is a troublesome sinuous 
leer, which can only be healed by keeping 
“the foot entirely at rest. 
The deep muscles, bound down in the pos- 
erior interosseal space, by the inter-muscular 
ayer of the aponeurosis, are found lying in this 
rder; the flexor digitorum communis, placed 
hnermost, upon the back of the tibia; the 
exor longus pollicis, on the fibula, and the 
bialis posticus between them, and partly con- 
eealed by them. Upon this last muscle are 
‘Situated the posterior tibial vessels and nerves. 
As they all of them have to pass nearly behind 
e inner ankle, the two outermost are gradu- 
ally approaching to the flexor communis, as 
they descend, till they are nearly in contact one 
With the other. As all these tendons, either 
| Primarily or secondarily, act upon the ankle- 
Joint, their action is retained after rupture or 
d vision of the tendo Achillis, so that the 
power of extension of the foot still remains, 
though in a feeble degree. 
Sal and pr of this region are the posterior 
e 
pe 
- 
r 
bial and peroneal, and are given off from the 
termination of the popliteal. The anterior ti- 
ie, ae ; : / 
__* See Dictionnaire des Sciences Medicales, ar- 
ticle Jambe. 
° 
REGIONS OF THE LEG. 
133 
bial also has here a course of a few lines, from 
its origin, till it perforates the interosseous liga- 
ment. The posterior tibial may be considered as 
the continuation of the trunk of the popliteal. 
It commences about an inch below the origin 
of the anterior tibial, and where the popliteal 
divides into this artery and the peroneal. The 
course of the posterior tibial may be defined 
by a line drawn from the middle of the ham, 
to a spot half an inch behind the inner mal- 
leolus. In this course it is accompanied by 
two veins, one on either side, also by the poste- 
rior tibial nerve ; in the upper part of the leg, 
this nerve lies to the inner or tibial side of the 
artery ; it soon, however, passes over it, and 
inferiorly it lies to its outer or fidular side. 
The posterior tibial artery is covered, in the 
upper and middle thirds of the leg, by the gas- 
trocnemius and soleus imrscles, but in the lower 
third only by the integuments, and by the su- 
perficial and deep fascie of the leg. In the 
upper third of its course, this artery rests upon 
the tibialis posticus muscle, in the middle 
third upon the flexor digitorum communis, 
and in the inferior third some fat and cellular 
membrane separate it from the tibia, and from 
the internal lateral ligament of the ankle-joint. 
In the inferior third of the leg, the posterior 
tibial artery runs nearly parallel to the inner 
edge of the tendo Achillis; between the os 
calcis and malleolus internus, it lies nearly in 
contact with the sheath of the flexor digitorum 
communis.* The only branch of surgical in- 
terest given off by this artery in the leg is the 
nutritious artery of the tibia, which comes off 
about its upper third, and in amputation at 
this part sometimes bleeds freely. 
In putting a ligature upon this artery, the 
difficulties attendant upon the operation vary 
according to the situation at which we seek for 
it. Itis favourably circumstanced for opera- 
tion in the inferior third of its course, being 
covered in the two upper thirds by the muscles 
of the calf. It may require to be tied fora 
wound in the sole of the foot, or for one behind 
the inner ankle. In either of these cases the 
artery may be found and tied with facility be- 
hind the inner malleolus. (See ANKLE-Jornt, 
Recion or.) When, however, itis deemed de- 
sirable to tie it at the lower third of the leg, it 
will be readily found by an incision of from 
two to three inches in length, performed mid- 
way between the inner border of the tibia and 
the tendo Achillis. After the division of the 
integuments, the superficial fascia, and the 
deep fascia, the artery will be met with di- 
rectly under the incision. Its accompanying 
veins sometimes completely conceal it; the 
nerve is here on the fibular side of it. 
In case of secondary hemorrhage after this 
operation, or in case of aneurism of the pos- 
terior tibial artery, forming in consequence of a 
wound of the artery in this situation, it may be 
necessary either to tie this vessel higher up in 
the leg, or to tie the popliteal femoral artery 
itself; it has been deemed prudent to give the 
patient the chance of success from the former 
* Sce article ANKLE-JOINT, REGION OF, 
