The study is a cross-sectional design aimed at investigating the relationship between lumbar lordosis, pelvic stability, and physical activity among patients with non-specific low back pain (NSLBP). The study will utilize imaging techniques such as X-rays and MRI to assess lumbar lordosis and pelvic alignment, along with functional assessments like the prone plank test to evaluate core stability and endurance. Participants will include individuals diagnosed with NSLBP, recruited through convenience sampling from a clinical or community setting. Inclusion and exclusion criteria will be applied, and informed consent will be obtained prior to participation. Lumbar lordosis angles will be measured through standardized radiological imaging protocols. Pelvic stability will be assessed using dynamic and static biomechanical tests, while physical activity levels will be evaluated through questionnaires. The prone plank test will measure core endurance, which will serve as a functional indicator of pelvic and lumbar stability. The data will be analyzed to explore the correlation between lumbar lordosis, pelvic stability, and physical activity levels. Gender-specific and age-specific analyses may also be performed. The study aims to provide insights into biomechanical and functional factors contributing to NSLBP, potentially guiding targeted interventions to improve lumbar-pelvic stability and physical activity for better management of NSLBP.