Page 231 - Clinical Anatomy

ECA4 7/18/06 6:47 PM Page 216

216 The lower limb

Fig. 157◊The ‘safe area’
for injections in the
buttock.

extending upwards to the iliac crest and outwards to the greater trochanter
—is implied, perfectly sound and safe advice this is. Many nurses, however,
have an entirely different mental picture of the buttock; a much smaller and
more aesthetic affair comprising merely the hillock of the natus. An injec-
tion into the upper outer quadrant of this diminutive structure lies in the
immediate area of the sciatic nerve!
A better surface marking for the ‘safe area’ of buttock injections can be
defined as that area which lies under the outstretched hand when the
thumb and thenar eminence are placed along the iliac crest with the tip of
the thumb touching the anterior superior iliac spine (Fig. 157).

The bones and joints of
the lower limb

The os innominatum

See ‘The pelvis’, pages 124–32.

The femur (Figs 158 and 159)
The femur is the largest bone in the body. It is 18in (45cm) in length, a mea-
surement it shares with the vas, the spinal cord and the thoracic duct and
which is also the distance from the teeth to the cardia of the stomach.
The femoral head is two-thirds of a sphere and faces upwards, medially