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.