Reliability and concurrent validity of 30-s and 5-time sit-to-stand tests in older adults with knee osteoarthritis.

The 30-s and 5-time STS tests are reliable assessment tools and correlate with knee muscle strength, pain, stiffness, and physical function in older adults with knee osteoarthritis. Key Points • The 30-s and 5-time STS test can serve as surrogate measures in various aspects of knee health, including muscle strength, pain levels, stiffness, and overall physical function, in older adults with knee osteoarthritis. • Both these STS tests are dependable tools, accessible for both experienced and inexperienced assessors to administer effectively.