Validity And Reliability Of The Four Square Step Test In Individuals With Rheumatoid Arthritis

This cross-sectional observational study aims to evaluate the validity and reliability of the Four Square Step Test (FSST) in individuals with rheumatoid arthritis. In addition, the study will investigate the associations between FSST performance and clinical parameters including disease activity, quality of life, pain, and muscle strength. All assessments will be conducted according to a pre-defined standardized protocol. The order of measurement tools will be randomized to minimize potential bias, and sufficient rest intervals will be provided between tests to prevent fatigue and performance effects. Participants will include individuals aged 18-65 years with a diagnosis of rheumatoid arthritis according to the ACR/EULAR 2010 classification criteria, who have been followed for at least 6 months, have had no major changes in treatment regimen in the last 4 weeks (e.g., initiation or change of DMARDs/biologics, high-dose steroid increase), can walk at least 10 meters independently, have a Mini-Mental State Examination score of 24 or higher, and are able to follow verbal instructions in Turkish to comply with study procedures. Appropriate statistical methods will be applied to assess validity, reliability, and associations between FSST and clinical parameters.