N3 Anatomy and Physiology AY 2023-2024

1. Sites of injection: Right anterolateral thigh for PCV and left anterolateral thigh for Penta

   • Targeted muscle: Vastus lateralis
     • Origin: Greater trochanter and linea aspera of femur.
     • Insertion: Patella via quadriceps tendon and then tibial tuberosity via patellar ligament.
     • Action: Extend leg at 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). Divide the muscle into thirds and administer the injection into the middle third of the muscle, in the outer anterolateral aspect, lateral to the midpoint of the thigh.

2. Preferred muscle for injection site: Deltoid

   • Origin: Acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), and spine of scapula (posterior fibers).
   • Insertion: Deltoid tuberosity of humerus.
   • Action: Lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially rotate arm at shoulder joint; posterior fibers extend and laterally rotate arm at shoulder joint.
   • How to locate: The deltoid muscle is a large, rounded, triangular shape. Find the acromion process, which is the bony point at the end of the shoulder. Trace an imaginary inverted triangle below the shoulder. The injection site will be approximately 2 inches below the bone and above the axillary fold/armpit, in the middle of the triangle.

References:

Berhane, Y., Worku, A., Demissie, M., Tesfaye, N., Asefa, N., Aniemaw, W., Weldearegawi, B., Kebede, Y., Shiferaw, T., Worku, A., Olijira, L., Merdekios, B., Ashebir, Y., Tadesse, T., Dessie, Y., Meseret, S., & Ayele, G. (2014). Children Who Received PCV-10 Vaccine from a Two-Dose Vial without Preservative Are Not More Likely to Develop Injection Site Abscess Compared with Those Who Received Pentavalent (DPT-HepB-Hib) Vaccine: A Longitudinal Multi-Site Study. PLoS ONE, 9(6), e97376. https://doi.org/10.1371/journal.pone.0097376