Note: Good day, class! My apologies for posting my answers in this forum discussion so late. I was setback last week by an illness that lasted for six days. I had informed our professors about this health condition and provided them with a medical clearance. I kindly ask for your consideration and understanding. Thank you.
Case 1:
Where are the sites of injection and what muscle is targeted in the injection?
- The site of injection would be the lateral side of the thigh in the midportion of the vastus lateralis muscle.
Write down its origin, insertion and action?
- Origin: Greater trochanter and linea aspera of femur.
- Insertion: Patella via quadriceps tendon and then tibial tuberosity via patellar ligament.
- Action: All four heads extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint. The primary action of the vastus lateralis is knee extension, meaning it straightens the knee joint. In the context of an infant, it's also used for leg movement.
How do you locate this area?
- To locate this area, start by positioning them on their back with the leg to be injected exposed. Next, locate the injection site, which is typically in the outer upper quadrant of the vastus lateralis muscle, situated on the front of the thigh. To pinpoint this area, find the midpoint between the greater trochanter (the bony part on the side of the hip) and the knee. This positioning and site selection are essential for a safe and effective injection procedure.
Case 2:
Which muscle is the preferred site for IM injection in this case?
- The deltoid muscle of the shoulder is the preferred site for an intramuscular (IM) injection in this case because the muscles in this area are relatively thick, and absorption is facilitated by their extensive blood supply.
Write down its origin, insertion and action?
- 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 do you locate this area?
- To locate this area, first ensure the individual is seated comfortably, with their upper arm accessible. Next, pinpoint the injection site, typically found in the middle third of the deltoid muscle, situated between the acromion process (the bony top of the shoulder) and the humeral head (the upper arm bone's top portion).
References:
Moore, Keith Leon, Dalley, Arthur F, Agur, Anne M. R. (2014). Clinically oriented anatomy (7th). Philadelphia: Wolters Kluwer, Lippincott Williams & Wilkins.
Snell, Richard S. (2012). Clinical anatomy by regions (9th). Baltimore, MD: Wolters Kluwer/Lippincott Williams & Wilkins.
Tortora, G., & Derrickson, B. (2012). Principles of ANATOMY & PHYSIOLOGY (13th ed.). John Wiley & Sons, Inc.