1.
Site of Injection: Anterolateral 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: Palpate the muscle below the greater trochanter and above the lateral femoral condyle. Divide the muscle into three parts and inject into the middle third of the muscle, in the outer anterolateral aspect, lateral to the midpoint of the thigh.
2.
Site of Injection: Upper arm
Targeted Muscle: Deltoid
Origin: Acromial extremity of clavicle, acromion of scapula, and spine of scapula
Insertion: Deltoid tuberosity of humerus
Action: Lateral fibers abduct arm at shoulder joint, anterior fibers flex and medially rotate arm at shoulder joint, and posterior fibers extend and laterally rotate arm at shoulder joint
How to locate: Palpate the acromion and trace an imaginary inverted triangle below the shoulder. The injection should be given 3-5 cm below the acromion, in the middle of the triangle.