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THE ABDOMEN. 1219 
The metatarso-phalangeal articulations are situated 1 in. behind the web of the 
toes. In disarticulating a toe, the transverse metatarsal hgament, which unites the 
heads of the metatarsal bones, should not be injured. 
The tendon of the tibialis posticus may be felt, and, by inverting the foot, seen, 
as it extends from behind the tip of the internal malleolus to the tubercle of the 
scaphoid ; it crosses the astragalus immediately above the sustentaculum tall. 
In the commonest form of club-foot, viz. talipes equino-varus, the tubercle of the 
seaphoid is approximated to the internal malleolus, so that tenotomy of the tendon 
should be performed through a puncture a little below the tip of the internal malleolus ; 
if the knife, after dividing the tendon, be carried down to the bone, the inferior calcaneo- 
scaphoid ligament will be divided oad the astragalo-scaphoid joint opened, a procedure 
which is called for before the foot can be brought into good position. 
Crossing the front of the ankle-joint, from within outwards, are the following 
tendons: viz. the tibialis anticus, the largest and most prominent; the extensor 
longus hallucis, the extensor longus digitorum, and the peroneus tertius. The 
extensor brevis digitorum gives rise to a fleshy pad which overlies the dorsal aspect 
of the calcaneo-cuboid jot. When the foot is everted, the tendon of the peroneus 
brevis may be seen extending from the tip of the external malleolus to the base of 
the fifth metatarsal bone ; immediately below it is the tendon of the peroneus longus, 
which, as it winds round the cub pid, is obscured by the fleshy fibres of the abductor 
minimi digiti muscle. The abductor hallucis muscle, althouch described along with 
the sole, forms a fleshy pad along the inner border of the foot below the susten- 
taculum tali. 
An incision, extending from the tubercle of the scaphoid to the middle of the 
inner border of the heel, will expose the various tendons, vessels, and nerves, as 
they pass from the inner ankle into the sole beneath the abductor hallucis. 
The dorsalis pedis artery may be mapped out on the surface by drawing a line from 
a point opposite the ankle-joint, midway between the tips of the two malleol, to the 
hinder end of the first interosseous space; the vessel may be compressed against 
the inner column of the tarsal bones. The internal saphenous vein and nerve lie 
between the anterior border of the internal malleolus and the tendon of the tibialis 
anticus ; the external saphenous vein and nerve take the same course as the tendon 
of the peroneus brevis. 
The internal plantar vessels and nerves lie alc ong the internal intermcnie 
septum, which corresponds to a line drawn from ane under surface of the inner 
tuberosity of the os calcis to the interval between the first and second toes. The 
external plantar vessels and nerves may be exposed by an incision along the 
external intermuscular septum, which runs in a line extending from the middle of 
the under surface of the heel to the fourth toe (Kocher); to map out the course 
of the plantar arch, draw a line across the sole from the inner side of the base of 
the fifth metatarsal bone to the hinder end of the first interosseous space. 
THE ABDOMEN. 
THE ANTERIOR ABDOMINAL WALL. 
The configuration of the abdomen varies with the age, sex, obesity, and muscular 
development ‘of the individual. In the child it is wider above than below, while 
the converse is the case in the adult female. It is most prominent in the region of 
the umbilicus, which is situated, normally, below the mid-point between the infra- 
sternal notch and the symphysis pubis, usually a little below the level of the highest 
part of the iliac crest, and opposite the middle of the body of the fourth lumbar. 
vertebra. In the obese, and especially when the abdominal muscles have lost their 
tone, the umbilical region becomes prominent and more or less pendulous, so that 
the umbilicus may come to he considerably below the normal level. In the child 
it is relatively lower than in the adult, in consequence of the undeveloped state of 
the pelvis. 
In spare subjects the lower end of the body of the sternum, the xiphoid carti- 
lage, and the costal margin, can readily be traced. The slight depression or notch 
