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: The injection site is about halfway between the knee (lateral femoral condyle) and the top of the femur (greater trochanter).
2.
Site of injection: Upper arm
Targeted muscle: 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: With the upper arm exposed, locate the acromion process by palpating the bony prominence to find the landmark for the deltoid muscle. In the middle of the deltoid muscle, one to two inches below the acromion process, is the injection site.