Inclusion Criteria:  Low back pain patients: aged 18 years or older, experienced non-specific CLBP of 3 months or longer, pain localized to the lumbar region. Knee OA patients: eligible participants must meet the knee OA diagnostic criteria according to the American College of Rheumatology (ACR).  Exclusion Criteria:  degenerative systemic diseases neurological symptoms lumbar stenosis spondylolisthesis history of spinal or knee surgeries pregnancy rheumatoid arthritis serious pathological conditions (inflammatory arthritis and malignancy) individuals who cannot read and understand documents written in the Arabic language.