1. 2-Month Old Female Infant
Site of Injection: Anterolateral aspect of thigh
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: Extends leg at knee joint
How to locate area:
1st - Position the patient lying down or being held by a parent.
2nd - Palpate the muscle below the greater trochanter and above the lateral femoral condyle (knee joint).
3rd - 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. 65-year-old grandfather
Site of Injection: Deltoid Muscle
Targeted Muscle: Deltoid Muscle
Origin: Acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers), and spine of spacula (posterior fibers)
Insertion: Deltoid tuberocity of humerus
Action: Lateral liberal 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 area:
1st - Position the patient so they are sitting comfortably with their arm visible from the shoulder to the top of the elbow.
2nd - Palpate the acromion (outer edge of the scapula) and trace an imaginary inverted triangle below the shoulder.
3rd - The injection should be administered in the middle of the triangle.