1. Vaccination for the 2-Months Old Infant (Situation 1)
Site of Injection: Anterior and lateral part of the thigh (Anterolateral thigh)
Targeted Muscle: Vastus Lateralis
Origin: Greater trochanter and linea aspera of the femur
Insertion: Patella via the quadriceps tendon and tibial tuberosity via the patellar ligament
Action: Extends the knee join
How to locate: Position the baby with their leg extended then divide the outer side of the thigh into three segments. Also, focus on the middle segment to locate the vastus lateralis muscle then to find this muscle on the outer thigh, gently palpate by pressing lightly
2. Vaccination for the 65-Year-Old Grandfather (Situation 2)
Site of Injection: Deltoid muscle in the upper arm
Targeted Muscle: Deltoid
Origin: Lateral part of the clavicle, acromion process, and spine of the scapula.
Insertion: Deltoid tuberosity of the humerus.
Action: The shoulder joint can move backward, forward, and away from the body
How to locate: The patient should either sit or stand with their arm relaxed then locate the deltoid muscle by finding the acromion process of the scapula and ask the patient to slightly raise their arm to help feel the muscle and ensure the injection is given a bit below the acromion process (2-3 fingers below) in the center of the muscle