RecruitingIndividual Differences in Gait and Osteoarthritis PainThe goal of this observational study is to look at inter-individual differences in knee osteoarthritis (OA) walking pain and performance. The main questions this study aims to answer are: Why do some people with knee osteoarthritis have more severe disabling pain than others, even though the degenerative changes in their knees are similar? What are the factors that contribute to walking pain in people with knee osteoarthritis? Participants will complete surveys, perform physical function tasks, get a knee X-ray and MRI, undergo non-invasive brain imaging, and undergo sensory testing.