Female patients aged 18-75 years with chronic low back pain (lasting at least 3 months) will be included in the study. Demographic data including age, height, weight, educational status, marital status, and comorbidities will be recorded. In addition, clinical characteristics such as pain duration, pain distribution, analgesic use, and concomitant musculoskeletal disorders will be assessed.

Uterine position will be evaluated based on pelvic magnetic resonance imaging (MRI) or pelvic ultrasonography reports obtained within the last year. According to uterine position, participants will be divided into two groups: posteriorly positioned uterus (retroverted and/or retroflexed uterus) and anteriorly positioned uterus (anteverted uterus).

Pain severity will be assessed using the Visual Analog Scale (VAS), and pain duration will be recorded in months. Pressure pain threshold measurements will be performed using an algometer at bilateral lumbar paraspinal muscles, gluteal regions, and the mid-deltoid muscle as a remote control point.

Central sensitization will be assessed using the Central Sensitization Inventory (CSI), and pain catastrophizing will be evaluated using the Pain Catastrophizing Scale (PCS).

All assessments will be conducted through face-to-face interviews. No additional laboratory tests, interventional procedures, or treatments will be applied to the participants within the scope of the study. Validated Turkish versions of all scales will be used. The collected data will be analyzed to investigate the relationship between uterine position and pressure pain threshold, central sensitization, and pain catastrophizing levels in women with chronic low back pain.

Inclusion Criteria:

Female, aged 18-75 years Presence of chronic low back pain (lasting at least 3 months) Availability of pelvic MRI and/or pelvic ultrasonography within the last year with assessable uterine position (anteverted, retroverted, retroflexed) Ability to read and understand Turkish and complete questionnaires Willingness to participate

Exclusion Criteria:

Pregnancy or childbirth within the last 6 months (postpartum period) History of lumbar spine surgery, vertebral fracture, or spinal malignancy Presence of inflammatory rheumatic disease (e.g., ankylosing spondylitis), severe neurological disease, or systemic disease affecting low back pain Severe cognitive impairment, communication problems, or major psychiatric disorder preventing participation Absence of pelvic imaging or inability to classify uterine position

The study population will consist of female patients aged 18-75 years with chronic low back pain (lasting at least 3 months) who are admitted to the Physical Medicine and Rehabilitation outpatient clinics of Bakırköy Dr. Sadi Konuk Training and Research Hospital and Istanbul Physical Therapy and Rehabilitation Training and Research Hospital during the study period. Participants will be recruited consecutively. Only patients with available pelvic MRI and/or ultrasonography within the last year allowing classification of uterine position will be included. All participants will be medically stable and able to complete the study assessments.