Muscular System Activity 3
- Both vaccines can be injected into the anterolateral thigh of the infant as long as the injection sites are at least an inch apart. The muscle targeted in this site is the vastus lateralis, which originates from the greater trochanter and linea aspera of the femur and inserts into the patella through the quadriceps tendon and then the tibial tuberosity through the patellar ligament. This muscle acts to extend the leg at the knee joint. This injection site can be located at the bulkiest part of the vastus lateralis.
- For a 65-year-old, the preferred intramuscular injection site would be the deltoid muscle. It originates from the acromial extremity of the clavicle and the acromion and spine of the scapula. It inserts into the deltoid tuberosity of the humerus and it acts to abduct the arm at the shoulder joint, flex and medially rotate the arm at the shoulder joint, and extend and laterally rotate the arm at the shoulder joint. The deltoid can be located 2-3 fingers down the acromion process, which feels like a small and flat structure and can be located by palpating the lateral edge of the shoulder. Once the deltoid muscle has been located, the injection can be given at the central and thickest portion of the muscle.