1.
Injection Site: Anterolateral Thigh
Targeted Muscle: Vastus lateralis
Origin: Greater trochanter and the linea aspera of the femur
Insertion: Patella via the quadriceps tendon and into the tibial tuberosity via the patellar ligament
Action: Extension of the knee joint
How to locate this area?: To locate the vastus lateralis muscle for injection, gently
palpate the lateral side of the thigh. Divide the area between the greater trochanter and the top of the knee into three equal vertical sections. The middle third of this section is typically used as the injection site.
2.
Preferred muscle for the site of injection: Deltoid in the upper arm
Origin: Lateral third of the clavicle, acromion process of the scapula, and spine of the scapula
Insertion: Deltoid tuberosity of the humerus
Action: Abducts the arm, flexion, lateral rotation, and extension of the arm
How to locate this area?: First, relax the patient's arm. Locate the acromion process of the scapula at the top of the shoulder. The injection site is approximately 2-3 fingerbreadths below the acromion process, in the thickest part of the deltoid muscle.