This document discusses intramuscular injection techniques. It begins by explaining that intramuscular injections are injected into large muscles because muscles have more blood vessels, allowing for faster drug absorption than subcutaneous tissue. Common sites for injection include the deltoid, gluteal, and thigh muscles. The document then reviews indications, contraindications, side effects, proper technique to minimize risks of infection or injury, and specific injection sites like the deltoid, vastus lateralis, gluteal muscles, and rectus femoris. It concludes by describing the Z-track injection method used to seal medications in muscle tissue and minimize discomfort.