Rotator cuff tendinopathy, one of the pathologies identified as part of the cluster of shoulder symptoms known as subacromial pain syndrome, is a common musculoskeletal shoulder condition. Resolution of pain and disability is poor despite treatment, with only about 50% reporting full recovery at 12 - 18 months. Prior studies suggest therapeutic exercise when used alone and with other interventions can have positive outcomes; however, not all patients with rotator cuff tendinopathy respond. Few studies have assessed the effects of exercise for individuals with chronic pain, especially brain driven mechanisms, thought to play a key role. In this study, we will use brain imaging to understand the mechanisms, identify predictors of a positive response to exercise, and the relationship to biomechanical and pain-related factors in patients with RC tendinopathy. The findings from this study will optimize the delivery and treatment response to exercise for individuals with shoulder pain.