The buttock is commonly used for intramuscular injections. These injections are given in the upper outer quadrant of the buttocks. Injections in both lower quadrants of the buttocks would endanger the sciatic nerve or nerves and vessels passing below the piriformis muscle. Injections in the upper inner quadrant may injure the superior gluteal nerve and vessels. Intragluteal injections in the upper outer quadrant are relatively safe from the superior gluteal nerve and vessels are branched in this region. Once you dissect. . . Replace the muscles of the buttocks in their correct anatomical positions. Review the attachments, action, and innervation of each muscle. Studying the functions of the muscles of the buttocks. Extend thigh. This movement is performed by the gluteus maximus. Abduct your thigh. This movement is performed by the gluteus medius, gluteus minimus muscle and tensor fascia lata. Laterally rotate your thigh. This movement is performed by the piriformis muscle, internal obturator muscle, the gastrocnemius muscle higher, lower gastrocnemius muscle, and quadratus femoris muscle. Review the anatomy of the safe injection site intragluteal. If you have completed the dissection of the pelvis and the perineum prior to dissection of the lower limb, to study the continuity of the muscles, vessels and nerves observed in the buttocks and pelvic regions. In the pelvis to identify the internal obturator muscle and keep the muscle back into the gluteal region. In the basin, to identify the piriformis muscle, then follow the muscle side of the greater trochanter of the femur. In the basin, to study the gluteal vessels and their relationship to the piriformis muscle and sacral plexus. Review the sacral plexus and its contribution to the sciatic nerve. Note that the muscles of the buttocks are innervated by branches of the sacral plexus nerve.