RESUMEN
Several studies have been carried out in the last decades showing that specific exercises for the multifidus muscle can aid the lumbar back pain treatment. Hence, it is very important to determine the exact location of these muscles for an electromyographic evaluation. The objective of this study is to conduct a literature review to show the different techniques used to place invasive electrodes and test a specific technique through an anatomic study in cadavers. PubMed database in the period of 1970 to 2009 was used. The results suggest that the needle should be introduced 2.5 cm laterally and 1.0 cm cranially from the most inferior point of the spinous process at a 45° medial inclination toward the vertebral laminae until reaching the periosteum. For the L5 level, the needle is inserted at the same angle, 2.5 lateral to the midline between the posterior superior iliac spines.