Radiofrequency and Pelvic Floor-Core Exercise for Chronic Low Back Pain in Women With Pelvic Floor Dysfunction

The goal of this clinical trial is to learn whether capacitive-resistive radiofrequency, a supervised core and pelvic floor exercise programme, or both together reduce low back pain in premenopausal women with chronic non-specific low back pain and pelvic floor dysfunction. The main question it aims to answer is: do the three treatments differ in lumbar pain intensity (0-10 visual analogue scale) 1 week after the treatment ends? Researchers will also compare pain quality, low back disability, pelvic floor symptoms, urinary incontinence, pelvic floor muscle function and lumbar mobility up to 3 months after treatment. Sixty women will be randomly assigned to one of three groups: * Radiofrequency: nine weekly 20-minute sessions applied to the lower back and, through a vaginal electrode, to the pelvic floor. * Exercise: a 12-week programme of supervised group sessions (three 30-minute sessions per week) for the core and pelvic floor muscles. * Combined: both treatments at the same time. Participants will complete questionnaires and a physical examination before treatment and 1 week, 1 month and 3 months after treatment ends.

Inclusion Criteria: * Women aged 18 years or older. * Non-specific low back pain located between T12 and the iliac crest, with or without referred pain to the lower limb. * Pain duration of more than 12 consecutive weeks. * Pain intensity of 3/10 or higher on a 0-10 visual analogue scale at screening. * Pelvic floor dysfunction, defined as a score above 0 on the Pelvic Floor Distress Inventory-20 (PFDI-20) or the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF). Exclusion Criteria: * Perimenopause or menopause. * Chronic pain in regions other than the lumbar and pelvic areas. * Current pregnancy or breastfeeding. * Physiotherapist-supervised pelvic floor muscle training in the previous 12 months. * Pharmacological treatment for any pelvic floor disorder. * Radiofrequency applied to the pelvic floor muscles in the previous 12 months. * Inability to understand study information (cognitive impairment). * Cardiac, metabolic or autoimmune disease. * Peripheral or central neurological disorder. * Previous abdominal, lumbar or pelvic surgery. * Skin disease or open wounds in the treatment area. * Active urinary tract or vaginal infection.