It is immunization day at the health center. The first patient is a 2-month old well female infant who is scheduled for the following vaccinations: pneumococcal conjugate vaccine (PCV), pentavalent vaccine (Penta) and oral polio vaccine. PCV and Penta are given via intramuscular route.
Where are the sites of injection? What muscle is targeted in the injection? Write down its origin, insertion and action. How do you locate this area?
The site of injection for this vaccination is in the anterolateral aspect of the thighs where the vastus lateralis muscle is located.
Vastus lateralis
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Origin: Greater trochanter and linea aspera of femur.
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Insertion: Patella via quadriceps tendon and then tibial tuberosity via patellar ligament.
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Action: Extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint.
This area can be located on the anterior lateral aspect of the thigh, which extends from one hand’s breadth above the knee to one hand’s breadth below the greater trochanter. The middle third of the muscle is used for injections.
The baby’s 65-year-old grandfather also came to the center because influenza vaccine is being offered to senior citizens. The flu vaccine is given intramuscularly.
Which muscle is the preferred site for IM injection in this case? Write down its origin, insertion and action. How do you locate this area?
The site of injection for this vaccination is in the upper arm or shoulder where the deltoid muscle is located.
Deltoid
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Origin: Acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), and spine of scapula (posterior fibers).
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Insertion: Deltoid tuberosity of humerus.
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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.
This area can be located by exposing the upper arm and finding the acromion process by palpating the bony prominence. The injection site is in the middle of the deltoid muscle, about 2.5 to 5 cm (1 to 2 inches) below the acromion process.
REFERENCES:
Anderson, Renée, and Wendy McKenzie. “7.4 Intramuscular Injections – Clinical Procedures for Safer Patient Care.” BCcampus Open Publishing, https://opentextbc.ca/clinicalskills/chapter/6-8-iv-push-medications-and-saline-lock-flush/.
Tortora, Gerard, and Bryan Derrickson. Principles of Anatomy and Physiology. 15th ed., Wiley, 2016.