McGill Stabilization Exercises Versus Pilates for Chronic Low Back Pain

The goal of this clinical trial is to compare the effects of McGill Stabilization Exercises and Pilates on pain, muscle thickness, lumbar flexibility, and disability in adults aged 30-50 years with chronic non-specific low back pain. The main questions it aims to answer are: * Do McGill Stabilization Exercises and Pilates reduce pain and disability in patients with chronic non-specific low back pain? * Do these interventions improve lumbar flexibility and transversus abdominis muscle thickness? Researchers will compare the McGill Stabilization Exercises group with the Pilates group to determine which intervention produces greater improvements in pain, muscle thickness, lumbar flexibility, and disability. Participants will: * Receive either McGill Stabilization Exercises or Pilates, according to their assigned study group. * Receive transcutaneous electrical nerve stimulation (TENS) and hot-pack therapy before the exercise intervention. * Attend treatment sessions twice weekly for six weeks, for a total of 12 sessions. * Complete assessments of pain intensity, disability, lumbar flexibility, and transversus abdominis muscle thickness at baseline and after six weeks.