1) 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?
Muscle Targeted: Vastus Lateralis
Origin: Greater trochanter and lateral lip of the linea aspera of the femur.
Insertion: Tibial tuberosity via the patellar ligament.
Action: Extends the leg at the knee joint.
Site of injection: Anterolateral thigh
Locating the injection site: Divide the anterolateral surface of the thigh into three equal sections from the hip to the knee. The appropriate site for the vastus lateralis injection is within the middle third of this region. Position one hand just below the hip joint at the upper portion of the thigh and the other hand just above the knee joint. The injection should be administered at the central point between these two points.
2) 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?
Muscle Targeted: Deltoid
Origin: Lateral third of the clavicle, acromion process, and spine of the scapula.
Insertion: Deltoid tuberosity of the humerus.
Action: Abduction of the arm (between 15 to 90 degrees), flexion, and medial rotation of the arm, as well as extension and lateral rotation depending on the fibers activated.
Site of injection: Upper arm
Locating the injection site: Identify the acromion process of the scapula, a prominent bony structure located at the top of the shoulder. From this point, measure approximately 2.5 cm inferiorly. The injection should be administered into the most substantial portion of the deltoid muscle at this level, ensuring that the lower third of the muscle is avoided to reduce the risk of injury to the radial nerve and nearby major blood vessels.