AIMS - The study aims to investigate the role of walking in achieving a subjective improvement in symptomatic osteoarthritis of the knee/s. Furthermore, the study will investigate whether walking improves performance based tests which objectively assess physical function in participants with knee osteoarthritis. Null hypothesis to be tested: There is no difference in a 12 week intervention of walking 6,000 steps, per day, in improving pain and self reported physical function, compared to the current Department of Health physical activity guidelines.