This study investigates sleep quality in patients with Rotator Cuff Syndrome (RCS) undergoing physical therapy treatment. Existing literature presents a gap regarding longitudinal studies evaluating the impact of physical therapy and different sleeping positions on sleep quality within this specific population. The central hypothesis is that physical therapy, combined with guidance on the best sleeping positions, reduces pain, improves shoulder function, and consequently promotes an improvement in sleep quality for RCS patients over time. The justification for this research lies in the need to better understand the relationship between physical therapy and sleep quality in RCS patients, aiming for the development of more effective and less invasive interventions. Previous studies have demonstrated that chronic pain, a common symptom of RCS, is intrinsically linked to sleep disturbances, which can lead to deleterious effects such as dopamine reduction, alterations in the descending pain modulation system, and central sensitization. Improvements in sleep quality have been observed after surgical procedures such as shoulder arthroscopy and arthroplasty, often associated with improved function and pain reduction. Thus, this study seeks to longitudinally evaluate whether physical therapy is capable of promoting a sustained improvement in sleep quality for patients with RCS