1. Site: Anterolateral thigh
Muscle: Vastus Lateralis
Origin: Greater trochanter and linea aspera of femur
Insertion: Patella via quadriceps tendon and then tibial tuberosity via patellar ligament
Actions: Extends leg at knee joint
How to locate: Identify the lateral thigh then divide it into three, from the top to the knee. The site in the middle , slightly off-center towards the outer side of the thigh and the muscle should be firm when the leg is relaxed and can be palpated easily.
Site: Upper Arm
Muscle: Deltoid
Origin: Acromial extremity of clavicle, acromion and spine of scapula
Insertion: Deltoid tuberosity of humerus
Actions: Lateral fibers abduct arm at shoulder joint, flex and medially rotate arm at shoulder joint (anterior fibers), extend and laterally rotate arm at shoulder joint (posterior fibers)
How to locate: Find the bony prominence of acromion process and place 2-3 fingers below and locate the injection site in the center and thickest portion.