Gluteus Maximus muscle in the buttocks: To find the correct location for injecting into the Gluteus maximus muscle, expose the buttocks and divide (in your mind) each buttock into four parts. Aim the injection into the upper quarter of the buttock (X on the diagram), towards the hip bone portion.he injection will go in outer middle third. The thigh is a good place to give yourself an injection because it is easy to see. When another person is giving the injection (picture on the right), the injection location does not change. Form a V with your fingers by separating your first finger from the other 3 fingers.