Knee osteoarthritis (KOA) is one of the most prevalent and disabling conditions among veterans and accounts for high morbidity and high costs for the VA. Importantly, chronic reductions in physical activity in patients with KOA may worsen pain, physical function, and exacerbate the metabolic consequences of obesity. The current proposal aims to address two important knowledge gaps in the management of KOA in order to improve pain and function. Promoting physical activity has been shown to be helpful in reducing pain and improving function in KOA, however, reliable ways to change behavior that can be easily employed are lacking. Our group has shown that social incentives derived from concepts from the field of behavioral economics to promote behavioral change and increase physical activity can be both practical and effective in other settings. The efficacy and safety of incentivizing physical activity using these approaches has not been studied in patients with KOA. Furthermore, whether adjunct therapies such as corticosteroid injections may be a helpful to reduce pain and disability and increase physical activity is unknown and is an additional knowledge gap addressed by the current proposal. Despite widespread use, definitive data to quantifying the benefit, if any, of corticosteroid injections are lacking. A large randomized trial tested the effects of corticosteroids injections every 3 months for a period of 2 years on patient reported pain. This study demonstrated no improvement in pain compared to saline and a small decline in cartilage thickness on MRI in the corticosteroid group. These data might suggest that corticosteroid injections result in more harm than good, however, there are critical weaknesses to this study including that pain and function were only assessed at 3-month intervals, while previous trials have suggested that peak benefit is expected at 4-8 weeks. We propose to fill these important knowledge gaps with an innovative and efficient pragmatic study. The aims are (1) To determine whether an incentive based on behaviorally-enhanced gamification can improve physical activity among patients with KOA and reduce self-reported pain and disability, and (2) to determine if corticosteroid injections can reduce pain and disability in patients with KOA when compared to lidocaine only. This double-blinded randomized clinical trial of 220 patients using a factorial and crossover design will leverage unique resources available through the Penn Center for Innovation to capture important patient-reported outcomes. We will randomize participants to receive social incentives with gamification to promote increases in physical activity. Each patient will also receive both corticosteroids and saline in random order. We will utilize innovative mobile applications for smart phones and wearable activity trackers through the Way-to-HealthTM platform and assess, in real time, the impact of the interventions on patient-reported function and pain as ...