Sun R, Tomkins-Lane C, Muaremi A, et al. - The present study was performed to evaluate the longitudinal association between physical performance (via real-life accelerometry) and physical capacity (laboratory measurement of gait speed) in patients with knee osteoarthritis (KOA), and to derive accelerometry measured thresholds associated with gait speed decline in KOA that may provide targets for disease-specific physical activity guidelines. Researchers extracted longitudinal data from the Osteoarthritis Initiative accelerometer sub-study from 1,229 participants assessed 2 years apart. They evaluated the effect magnitude and direction of each predicting feature on the longitudinal capacity status among KOA patients. Feature thresholds that may increase the probability of gait decline were established using a novel data interpretation method. These distinguished thresholds may give meaningful information for establishing specific physical activity guidelines for KOA.