Situation 1
- Site of Injection: Anterolateral Thigh
- Targeted Muscle: Vastus Lateralis
- Origin: Greater trochanter and linea aspera of femur.
- Insertion: via the quadriceps tendon to the patella, and via the patellar ligament to the tibial tuberosity.
- Action: Extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint.
- How to Locate the area of the muscle: After locating the femur's greater trochanter, palpate the lateral aspect of the thigh. Between the hip and the knee, the injection site is roughly in the middle portion of the thigh.
Situation 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 the humerus.
- Action: At the shoulder joint, posterior fibers extend and laterally posterior fibers extend and laterally rotate arm; lateral fibers abduct arm; anterior fibers flex and medially rotate arm at shoulder joint.
- How to Locate the area of the muscle: Approximately 2-3 fingerbreadths below the acromion process on the lateral portion of the upper arm is the injection site. Locate the bony protrusion on top of the shoulder.