The aim of this clinical trial is to investigate the effects of an attention shift-based rehabilitation program on clinical outcomes in individuals with rotator cuff-related shoulder pain (RCRSP). The study will evaluate the effects of an attention shift approach, in which motor tasks targeting regions outside the shoulder are performed concurrently with standard shoulder exercises, on pain, functional status, and pain catastrophizing. These results will be compared with those of a standard shoulder rehabilitation program.

The main questions this study aims to answer are:

Is there a difference in pain levels between individuals with RCRSP who participate in an attention shift-based rehabilitation program and those who participate in a standard exercise program? Is there a difference between these two rehabilitation approaches in terms of shoulder function and pain catastrophizing?

Participants will:

Be randomly assigned to either an attention shift-based rehabilitation group or a standard shoulder rehabilitation group Participate in supervised exercise sessions twice per week for 6 weeks Attend sessions lasting approximately 60-75 minutes Undergo clinical assessments at baseline and at week 6

A total of 46 participants will be included in the study based on the results of a priori power analysis. This study is designed as a randomized, parallel-group clinical trial. Participants diagnosed with rotator cuff-related shoulder pain (RCRSP) will be randomly allocated into two groups using a computer-generated randomization program: the Attention Shift-Based Rehabilitation Group (Group 1) and the Standard Rehabilitation Group (Group 2).

Both groups will receive standardized patient education and participate in a supervised exercise program. The Standard Rehabilitation Group will undergo a structured shoulder rehabilitation program consisting of range of motion, stretching, and strengthening exercises.

In the Attention Shift-Based Rehabilitation Group, participants will perform the same exercise program concurrently with additional motor tasks targeting body regions outside the shoulder (e.g., lower extremity or contralateral limb movements). These concurrent tasks are designed to shift attentional focus away from the painful shoulder region during exercise performance.

The intervention will be administered twice per week for a total of 12 sessions over a 6-week period. Each session will last approximately 60-75 minutes and will be supervised by a physiotherapist to ensure proper execution and adherence.

Assessments will be conducted at baseline (pre-intervention), at the end of the 6-week intervention period, and at 12 weeks as a follow-up assessment.

Inclusion Criteria:

• Having symptoms persisting for at least 3 months
• Experiencing pain intensity of at least 3 on the Numeric Pain Rating Scale (NPRS) during activity
• Presence of a painful arc during shoulder flexion or abduction
• Positive Neer test or Hawkins-Kennedy test
• Pain provoked by resisted external rotation/abduction of the humerus, or a positive Jobe (Empty Can) test
• Having a clinical diagnosis of subacromial pain syndrome, rotator cuff tendinopathy, subacromial bursitis, or symptomatic partial/full-thickness rotator cuff tear
• Being able to understand and complete questionnaires in Turkish

Exclusion Criteria:

• Presence of adhesive capsulitis (≥30% limitation in passive range of motion)
• Advanced osteoarthritis of the shoulder
• History of fracture or dislocation affecting the shoulder region
• Advanced acromioclavicular joint pathology
• Massive rotator cuff tear (positive lag signs)
• Previous shoulder surgery
• Presence of neurological disorders
• Diagnosis of rheumatoid arthritis
• History of cancer
• Symptomatic cervical spine pathology
• Corticosteroid injection to the shoulder within the past 6 weeks
• Cognitive impairments that may interfere with the ability to perform clinical tasks or execute attention shift-based exercises

Participants will be blinded to group allocation.