Ultrasound image and landmarks of the erector spinae plane block. Ultrasonographic visualisation of the needle positioning after the injection of the local anaesthetic in the interfascial plane. Note the distribution of the local anaesthetic observed in the interfacial plane between the erector spinae muscle and the lumbar transverse process.ES = Erector spinae complex; TP = transverse process; IT = intertransversarii lumborum muscles; LA = local anaesthetic; IFP = interfascial plane