Effectiveness of ultrasound-guided percutaneous electrical stimulation of the inferior and superior gluteal nerves as treatment for gluteus maximus and medius muscle dysfunction after an episode of low back pain: randomized clinical trial

Percutaneous ultrasound-guided neuromodulation (US-guided PNM) is the electrical stimulation of a peripheral nerve at some point along its pathway or at a muscular motor point under the guidance of an ultrasound probe with a therapeutic objective. The application of electrical current to a peripheral motor nerve is associated with a motor response that results in an uncontrolled, anarchic and exaggerated response of the musculature, which is normalized after the application of the electrical current. In 2016, the authors of the book Invasive Physiotherapy, Fermín Valera and Francisco Minaya, developed by themselves based on the fundamentals of segmental dry needling and neurofunctional acupuncture created by Dr. Alejandro Elorriaga. The authors defined that the application parameters to achieve the best result to the electrical stimulus are controversial, due to the high variability in the literature, but knowing that the most important parameter is the frequency, where studies are observed in which they have used from 2 to 100Hz looking for the motor response. The parameters of the protocol created are: frequency of 10Hz, pulse width of 250us, with a motor or sensory response, performing 8 stimulations of 8 seconds duration, with 8 seconds of rest, with the aim of improving neuromuscular function, muscle recruitment patterns and motor control. Although the scientific basis of the authors were 3 articles, none of which were aimed at improving muscle function, but were for neuropathic pain, chronic pain, and treatment of overactive bladder, the basis of clinical observation is correct and many studies currently using their protocol show improvements at the functional level. In a review of neuromodulation and muscle function, studies that carry out percutaneous stimulation use frequencies of 2Hz to 10Hz, using the protocol of Garrido F. V., Muñoz F. M. , which, as stated above, was not specifically designed to improve muscle function, while the studies that carry out transcutaneous stimulation use much higher frequencies, from 20Hz to 100Hz, all obtaining positive results. For this reason, and the great difference between the frequencies, the need to carry out specific research on the benefits that percutaneous stimulation with a frequency range of 20-100 HZ. The hypotheses of this study are,US-guided PNM, with frequency sweeps of 20Hz -100Hz increases static and dynamic strength, more relevantly than current 10Hz protocols.