Pain Phenotypes in Individuals With Chronic Low Back Pain

This observational cross-sectional study aims to determine pain phenotypes in individuals with chronic low back pain (CLBP). Participants will be classified according to a mechanism-based clinical pain phenotyping algorithm as having nociceptive, neuropathic, nociplastic, or mixed pain. Clinical history, quantitative sensory assessment, pain characteristics and distribution, central sensitization-related symptoms, disability, health-related quality of life, and pain catastrophizing will be assessed. In addition, the intra-rater and inter-rater reliability of the pain phenotyping algorithm will be investigated, and the clinical characteristics of different pain phenotypes will be compared.

Inclusion Criteria: * Low back pain persisting for at least 3 months or present for at least 3 months during the previous 6 months, defined as pain located between the posterior lower costal margins and the inferior gluteal folds * Pain intensity ≥2 on the Numeric Rating Scale * Willingness to participate in the study Exclusion Criteria: * Inability to read and write Turkish * History of lumbar surgery * Presence of a systemic condition affecting sensory function * History of spinal surgery within the previous 6 months or suspected spinal fracture * Inability to complete the study assessments