Thirty second chair stand test: Test-retest reliability, agreement and minimum detectable change in people with early-stage knee osteoarthritis.

The 30CST demonstrated a practice effect between the first and second tests, which was no longer apparent by the third test. Despite this, scores demonstrated excellent intra-session reliability. MDC estimates provide clinicians and researchers with the smallest change that can be detected by the instrument beyond measurement error for individuals and groups in community-dwelling adults with knee OA.