(2) Lateral thigh (vastus lateralis muscle). The vastus lateralis muscle, part
of the quadriceps group of four muscles of the upper leg, is located on the outer, lateral
thigh. The injection site is about a hand's width above the knee to a hand's width below
the groin (or hip joint) (see figure 2-3). Injections outside this area may hit a bone, a
nerve, or blood vessel.
Figure 2-3. Location for thigh injection.
(a) The volume of medication given in this site can be up to two
milliliters injection in an adult.
(b) The needle length must not be less than one inch and should not
exceed one and one-half inches for adults. A one and one-fourth inch needle is
(c) To administer an injection, make sure the patient's lateral thigh is
completely exposed so you can visualize the injection site. The patient should be lying
on his back (supine) or seated.
Do not inject into the areas close to the knee or hip bone.
(e) There are no main blood vessels or nerve trunks in the lateral thigh
injection site. There is a cutaneous nerve (lateral femoral) superficially located and
sometimes damage to these nerves is reported.