1. Injection Site: Anterolateral Thigh
Targeted Muscle: Vastus lateralis
Origin: Greater trochanter and lateral lip of the linea aspera of the femur
Insertion: Patella via the quadriceps tendon and tibial tuberosity via the patellar ligament
Action: Extends the leg at the knee joint
How to locate?: To landmark the vastus lateralis, position the patient lying down or being held by a parent. Palpate the muscle below the greater trochanter and above the lateral femoral condyle (knee joint).
2. Preferred IM injection site: Deltoid in the upper arm
Origin: Lateral third of the clavicle, acromion, and spine of the scapula
Insertion: Deltoid tuberosity of the humerus
Action: Abduction, flexion, medial and lateral rotation, and extension of the arm
How to locate?: The patient should be sitting comfortably with their arm visible from the shoulder to the top of the elbow. Palpate the acromion (outer edge of the scapula) and trace an imaginary inverted triangle below the shoulder. The injection should be given 3-5cms below the acromion, in the middle of the triangle.