Page 222 - Clinical Anatomy

ECA4 7/18/06 6:47 PM Page 207

The anatomy and surface

markings of the lower limb

Bones and joints

The tip of the anterior superior spine of the ilium is easily felt and may be
visible in the thin subject. The greater trochanter of the femur lies a hand’s
breadth below the iliac crest; it is best palpated with the hip abducted so
that the overlying hip abductors (tensor fasciae latae and gluteus medius
and minimus) are relaxed. In the very thin, wasted patient the greater
trochanter may be seen as a prominent bulge and its overlying skin is a
common site for a pressure sore to form in such a case.
The ischial tuberosity is covered by gluteus maximus when one stands. In
the sitting position, however, the muscle slips away laterally so that weight
is taken directly on the bone. To palpate this bony point, therefore, feel for it
uncovered by gluteus maximus in the flexed position of the hip.
At the knee, the patella forms a prominent landmark. When quadriceps
femoris is relaxed, this bone is freely mobile from side to side; note that this
is so when you stand erect. The condyles of the femur and tibia, the head of the
fibula and the joint line of the knee are all readily palpable; less so is the
adductor tubercle of the femur, best identified by running the fingers down
the medial side of the thigh until they are halted by it, the first bony promi-
nence so to be encountered.
The tibia can be felt throughout its course along its anterior subcuta-
neous border from the tibial tuberosity above, which marks the insertion of
the quadriceps tendon, to the medial malleolus at the ankle. The fibula is sub-
cutaneous for its terminal 3in (7cm) above the lateral malleolus, which
extends more distally than the stumpier medial malleolus of the tibia.
Immediately in front of the malleoli can be felt a block of bone which is
the head of the talus.
The tuberosity of the navicular stands out as a bony prominence 1in (2.5
cm) in front of the medial malleolus; it is the principal point of insertion of
tibialis posterior. The base of the 5th metatarsal is easily felt on the lateral
side of the foot and is the site of insertion of peroneus brevis.
If the calcaneus (os calcis) is carefully palpated, the peroneal tubercle can be
felt 1in (2.5cm) below the tip of the lateral malleolus and the sustentaculum
tali 1in (2.5cm) below the medial malleolus; these represent pulleys respec-
tively for peroneus longus and for flexor hallucis longus.

Bursae of the lower limb

A number of these bony prominences are associated with overlying bursae
which may become distended and inflamed: the one over the ischial
tuberosity may enlarge with too much sitting (‘weaver’s bottom’); that
in front of the patella is affected by prolonged kneeling forwards, as in
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