Introduction: Low back pain affects approximately 18.5% of the Brazilian population in adulthood, significantly impacting the quality of life and generating substantial costs for the health system. The Global Postural Reeducation Method (GPR) is a promising therapeutic alternative due to its multidimensional approach, capable of improving postural control and reducing pain. Objectives: to evaluate the Efficacy of the RPG method compared to simulated RPG (SHAM) in treating patients with chronic nonspecific low back pain. Methods: Randomized sham-controlled clinical trial. Forty-two adult individuals with chronic nonspecific low back pain will be recruited and distributed into two groups: the Experimental Group (EG), which will receive GPR sessions, and the Control Group (CG), which will receive RPG-SHAM sessions. Both groups will be treated for 30 minutes once a week for 8 weeks. Descriptive analysis will be performed, continuous variables will be summarized to the mean, and standard deviation and categorical variables will be summarized as absolute and relative frequencies. To assess the effects of the intervention over team, analysis of variance (ANOVA) with repeated measures will be used, with a significance level of 5% (p < 0.05). Expected Results: This study is expected to provide robust evidence on the effectiveness of RPG in treating patients with low back pain, contributing to a better understanding of this complex health condition. The results will potentially positively impact the clinical practice of Orthopedic Physiotherapy, offering an exercise-based and accessible approach for treating patients with low back pain.

Low back pain is the most prevalent musculoskeletal condition in the world. According to the Institute for Health Metrics and Evaluation (IHME), there are 570 million prevalent cases worldwide, accounting for 7.4% of the Years Lived with Disability (YLD) or Years Lived with Inability. Of these conditions, low back pain is the leading cause of disability in more than 160 countries. Given this, it is known that this condition significantly impacts quality of life and generates substantial costs for health systems worldwide. In Brazil, approximately 18.5% of the population in the adult phase complains of pain at some moment in life. Still in the country, a study showed that between 1990 and 2017 this condition increased by 26.83%, being one of the three most significant causes of Disability Adjusted Life Years (DALYS) or Years of Life Lost Adjusted for Disability.

Global Postural Reeducation (GPR) is one method of proprioceptive inhibition that can facilitate movement. It was developed by Phillippe Emanuel Souchard in 1987 and is based on the theory of myofascial chains. The method's premise is that a change that presents in a particular group of muscles resonates in compensations and alterations throughout the myofascial chain. Therefore, the technique aims to reorganize these changes.

These corrections are made through concentric isometric exercises with manual resistance imposed for the therapist carried out to the far away of one stretching progressive and sustained in order to inhibit hyperactivated muscles through a specific sequence of active postures in increasingly eccentric positions of the static muscles applied in joint de-coaptation also progressive. The postures do not have a relationship of dependence and are chosen after a specific evaluation of the method.

Some research has been developed using this method in the last few years. The object of study in these studies varies between the effects on the treatment of nonspecific postural deviations, neck pain, and back pain (nonspecific). There are even studies that compare the treatment of low back pain with other methods. However, most lack methodological rigor, and none are compared with the RPG-SHAM.

The World Health Organization (WHO) guideline for non-surgical treatment of chronic primary low back pain in adults in primary and community care settings, published in 2023, recommends physical exercise and manipulative therapy as indicated alternatives. Thus, in view of its characteristics, where it is used for exercises to stimulate the inhibition of the hypertonic muscles and the therapy manipulative applied during the execution, the method GPR can be one alternative therapy to the low back pain chronicle nonspecific. Furthermore, as healthcare professionals frequently recommend this method, it is essential to check your effectiveness one time when there is a lack of scientific evidence and the need for studies with more considerable rigor methodological, as comparing the method with one procedure identical but simulated ( SHAM ), that is a sham-controlled study.

Thus, knowing the effects of the GPR method in reducing chronic nonspecific low back pain can contribute to the clinical practice of the physiotherapist since it is a non-pharmacological intervention based on exercises and that is widely inserted and disseminated in physiotherapy services but with little research that supports evidence-based practice. There is, therefore, a lack of high-quality studies in the scientific literature that evaluate the effects of this procedure in the management of chronic nonspecific low back pain in comparison with a sham group to support its therapeutic indication. Given the above, this research aims to evaluate the effectiveness of the GPR method compared to GPR-SHAM in treating people with chronic nonspecific low back pain through a randomized, sham-controlled clinical trial.

JUSTIFICATION:

Low back pain is an apparent public health problem that contributes to worsening quality of life and overloading health services. It is also a potential employment problem that causes many economically active individuals to be removed from their work environments. Recent epidemiological studies have shown the high prevalence of this complex health condition, which reinforces the importance and need for a practical approach.

Several therapeutic approaches are recommended in the guidelines for the treatment of low back pain, such as those from NICE, JOSPT, and WHO. The recommended therapies are health education, manual therapy, and physical exercise. Although not mentioned in these documents, it consists of a proprioceptive method of muscle inhibition; that is, it is a physical therapy based on exercises.

Data available on the Souchard GPR Institute-SP website report that about 22.000 (twenty-two thousand) physiotherapists practice GPR in Brazil and more than 17 (seventeen) other countries. However, Evidence-Based Practice (EBP) still has many limitations since several available studies lack methodological rigor and have a high risk of bias and sometimes questionable results due to the lack of control in conducting the studies.

In a study of meta-analysis, "Effectiveness of Global Postural Reeducation in Chronic Nonspecific Low Back Pain: Systematic Review and Meta-Analysis" even after a careful and in-depth search in the databases, including also using from the literature gray, due to the very few studies available about the GPR method for the outcome of this research, showed that no research performed masking of the patients. In addition, the article also demonstrated that just four of the eight articles found had notes bigger than five after the assessment from the PEDro scale, with one getting a score of two.

Therefore, masking patients in clinical studies is a fundamental practice to control biases, and an effective way to carry out this masking is through a sham-controlled group. In that model, the group control receives one simulated intervention similar to the original one, allowing the real effect to be isolated from the therapy.

In a study which investigated the effects of dry cupping therapy compared to sham cupping therapy in the treatment of chronic nonspecific low back pain, it was possible to identify that there was no difference between the interventions, showing what if treats of one treatment ineffective. In this form, the search with one sham-controlled group was essential to verify the effectiveness of the intervention and contribute scientific information to decision-making by healthcare professionals.

Research with a more significant scientific quality contributes to professionals' health commitment to offering community treatments adequately tested, with known and evidence-based effects. Therefore, this research project aims to contribute to a more significant understanding of the treatment of people with low back pain chronicle nonspecific, in addition to having the possibility of promoting evidence for an accessible, non-pharmacological, and potentially effective treatment.

Inclusion Criteria:

• Adults aged between 18 and 55 years with chronic non-specific low back pain,
• Participants who voluntarily agree to participate and sign the Free and Informed Consent Form,
• Participants who have never done any treatment with the GPR method, and
• Participants who have not been undergoing physiotherapy treatment for at least 2 months.

Exclusion Criteria:

• Patients with pain lumbar acute, or it is, with symptoms gifts there is less of dose weeks, what carried out blocking medicinal in the column us last six months;
• Patients with hernia of disk of type extruded and/or kidnapped;
• Patients in possess or be in investigation of any kind of neoplasia;
• Patients who have undergone any type of surgery with placement of any type of prosthesis in the spine;
• Intellectual or sensory disability that prevents them from understanding commands or describing symptoms;
• Patients who have a significant change in tactile sensitivity that prevents them from reporting any symptoms;
• Patients who have any type of vestibular changes;
• Serious pathologies of the spine;
• Amputation of upper or lower limbs;
• Spinal Cord Injury;
• Low back pain with sacroiliac irradiation; any type of rheumatic diseases, such as: Rheumatoid Arthritis, Fibromyalgia, and others;
• Patients that be performing or carried out last two months any type of conservative treatments, such as: Acupuncture, hydrotherapy, manual therapy, Pilates, conventional physiotherapy, and others; and
• Patients who have travel plans in the coming months.