The 37 subjects of the experimental group (EG) will receive an application of monopolar electrical diathermy by radiofrequency emission (MDR) by means of the Physicalm® device (developed by the electro-medicine company Biotronic Advance Develops SL), on the lumbar muscles by means of rotary movements and translation, adapting to the muscle fibers of the lower back, contacting and applying the treatment to the active myofascial trigger points of the following muscles: quadratus lumborum, multifidus and iliocostalis, following the PGM maps described by Travell and Simons. A pulsed emission of 840 KHz and 30v will be carried out dynamically for a treatment time of 20 minutes. 2 weekly sessions will be performed for 4 weeks, a total of 8 treatment sessions.~The 37 subjects in the control group (CG) will be administered a placebo treatment consisting of the same execution protocol as the EG, but with a non-emitting device whose software and hardware will be exactly the same as that used in the EG. The intervention will be simulated for 20 minutes.~A pulsed emission of 840 KHz and 30v will be carried out dynamically for a treatment time of 20 minutes. 2 weekly sessions will be performed for 4 weeks, a total of 8 treatment sessions.~The outcome assessor and study statistician will be blinded throughout the entire process.~A baseline assessment of the primary and secondary outcome measures will be performed before randomization of the participants to the different groups, an immediate post-treatment assessment (1 day after the last intervention) and an assessment two months after the end of the procedure intervention (follow-up).
A total of 74 people diagnosed with non-specific chronic low back pain of more than 3 months of evolution and who are not currently undergoing any type of treatment will be recruited, with ages between 35 and 65 years. A random distribution will be made into two treatment groups (monopolar diathermy by radiofrequency versus placebo). Participants will receive treatment twice per week for a period of four weeks, in the physiotherapy laboratories of the University of Almería, with a follow-up evaluation post-intervention (one months) and two months after the end of treatment. At their first visit, participants will be screened for study eligibility according to the study inclusion and exclusion criteria, and will be evaluated by a therapist blinded to the intervention. After this face-to-face evaluation, patients will be randomly assigned to one of the two groups and will receive treatment for low back pain according to their random assignment group by two therapists belonging to the research group and trained in the techniques used.