BACKGROUND - Over 8.75 million people in the United Kingdom have painful osteoarthritis in one or both knees and a third of people of 45 years old have sought treatment. It has been well established that physical activity in mild - moderate osteoarthritis can provide improvement in symptoms and physical function. Current research is evaluating what modality of physical activity is best to achieve these improvements. A preliminary pedometer study in 2003 demonstrated symptomatic and functional improvement in knee osteoarthritis. A recent observational study has found that increased walking activity, with 6,000 steps per day being optimal, decreased the risk of functional limitation in knee osteoarthritis. Therefore, the purpose of this study is test evaluate the effectiveness of these recent recommendations against current UK physical activity guidelines.