*4.2.2 Anterior quadratus lumborum block*

An in-plane approach is performed using an anterior-posterior or posterioranterior trajectory. The target of the local anesthetic is the posterior surface of the quadratus lumborum muscle. The position of the needle tip is between the erector spinae (ES) and the quadratus lumborum muscle (**Figures 9** and **10**) [21, 23, 26].
