Cadaveric Evaluation of Different Approaches for Quadratus Lumborum Blocks

Figure 1

Illustration demonstrating the needle trajectory and tip location of the three different approaches to the ultrasound-guided QL block. With an anteroposterior needle trajectory, the target injection point of a lateral QL block (a) is the anterolateral margin of the QL, and that of posterior QL block (b) is the LIFT on the posterior surface of the QL. For a posterior QL block with posteroanterior needle trajectory (an alternative approach) (c), the needle is advanced towards the LIFT on the posterior surface of the QL (ES, erector spinae; LD, latissimus dorsi; LIFT, lumbar interfascial triangle; QL, quadratus lumborum; PM, psoas major; EO, external oblique muscle; IO, internal oblique muscle; TA, transversus abdominis muscle).