1.) Sites of injection: anterolateral thigh
Targeted muscles: vastus lateralis
Origin: lateral intermuscular septum, lateral lip of the linea aspera and the gluteal tuberosity
Insertion: patella and medial patellar retinaculum
Action: extends leg
How to locate area: Palpate the muscle below the greater trochanter and above the lateral femoral condyle (knee joint). Divide the muscle into thirds and administer the injection into the middle third of the muscle, in the outer anterolateral aspect, lateral to the midpoint of the thigh.
2.) Site of injection: ventrogluteal site
Targeted muscles: gluteus medius
Origin: external surface of the ilium between the posterior and anterior gluteal lines
Insertion: greater trochanter of the femur
Action: abducts the femur and medially rotates the thigh
How to locate area: draw imaginary lines from major bone endpoints of the thigh and hip, creating a triangle. Then, you would draw imaginary median lines from each corner of the triangle. Where these lines meet is the injection point.