This project will address the Research Question: Can a non-intrusive physical activity tracking tool, combined with a group education session and advice from a physiotherapist (PT), increase physical activity in patients with knee osteoarthritis (OA)? The investigators focus on knee OA because it is common (affecting 1 in 10) and can be debilitating. Being physically active improves pain, mobility and quality of life; however, less than half of patients are active. Combining the best evidence in OA care and digital technology, the investigators propose a new model of care for improving physical activity in patients with OA. Our primary objective is to determine whether a model involving 1) a group education session, 2) the use of Fitbit Flex, a commercially available physical activity tracker, and 3) remote coaching by a PT can improve physical activity and reduce sedentary time in patients with knee OA. This model of care is in line with the goal of Mary Pack Arthritis Program (MPAP) to optimize activity independence of OA patients with MPAP's available human resources. In this proof-of-concept randomized controlled trial (RCT), the investigators hypothesize that compared to a control group (i.e. the Delayed Intervention group), participants in the Immediate Intervention Group will 1) increase moderate/vigorous physical activity (MVPA), 2) reduce sedentary time, 3) improve in OA disease status, and 4) improve in their self-efficacy of OA management, 4) To examine whether individuals in the Intervention Group will show improved cognitive function over the intervention period compared to the control group, and 5) To examine the pre-intervention factors that predict the degree to which individuals in the Intervention Group increase MVPA and reduce sedentary time.