Which landmark method is correct for administering an IM injection in the vastus lateralis?

Which landmark method is correct for administering an IM injection in the vastus lateralis?

• A. Palpate to find greater trochanter and knee joints; divide vertical distance between these two landmarks into thirds; inject into the middle third.
• B. Locate the acromion process; inject only into the upper third of muscle that begins about two fingerbreadths below the acromion.
• C. Locate the greater trochanter, iliac tubercle, and iliac crest; place palm over the greater trochanter, over iliac tubercle, along the ileum; inject into center of V formed by the fingers.
• D. Displace the skin by pulling the skin down or to one side about 1 inch with the non-dominant hand before administering the injection.

Answer: (A)

The key idea is using palpable landmarks to locate the safe, thick part of the vastus lateralis for an IM shot. To do this, feel for the greater trochanter at the hip and the lateral femoral epicondyle near the knee. Imagine a line between these two points and split that distance into three equal segments. The injection goes into the middle third of the muscle. This position places you in the thickest portion of the vastus lateralis, away from bone and major vessels or nerves, which helps ensure the medication is delivered into muscle tissue rather than subcutaneous tissue or bone. The other approaches point to different sites (like the deltoid or ventrogluteal) or describe skin handling rather than landmark-based placement for the vastus lateralis, so they don’t fit this specific site and method.

The key idea is using palpable landmarks to locate the safe, thick part of the vastus lateralis for an IM shot. To do this, feel for the greater trochanter at the hip and the lateral femoral epicondyle near the knee. Imagine a line between these two points and split that distance into three equal segments. The injection goes into the middle third of the muscle. This position places you in the thickest portion of the vastus lateralis, away from bone and major vessels or nerves, which helps ensure the medication is delivered into muscle tissue rather than subcutaneous tissue or bone.

The other approaches point to different sites (like the deltoid or ventrogluteal) or describe skin handling rather than landmark-based placement for the vastus lateralis, so they don’t fit this specific site and method.