RecruitingClinical trialUpper and Lower Extremity Exercise and Exercise-Induced Hypoalgesia in Knee OsteoarthritisThe objective of the study is to explore the effects of arm exercise (UE, arm ergometer) vs. leg exercise (LE, cycling ergometer) on exercise-induced hypoalgesia (EIH), central pain mechanisms and knee pain in people with knee osteoarthritis (OA). Furthermore, we will explore relations of socioeconomic status, racial discrimination, acculturative stress, and autonomic function to exercise effects on EIH, central pain mechanisms, and knee pain. This will be a pilot randomized cross-over study where all participants undergo Day 1 (baseline assessments), Day 2 (UE or LE), and Day 3 (UE or LE).