Figure 43-18 Caudal technique. A, Palpating fingers locate the sacral cornua by using equilateral triangle (shown in Fig. 43-5 ). B, Needle insertion is carried out by insertion and withdrawal in stepwise fashion (so-called 1-2-3-insertion), until needle can be advanced into the caudal canal and solution can be injected easily (without creation of a subcutaneous "lump" of fluid).