Here is the design of a clinical trial:

Official Title: Rotator Cuff Unloading Versus Loading Exercise Program in Patients With Shoulder Pain and Rotator Cuff Tear: a Randomized Clinical Trial

Included conditions:
- Shoulder Pain
- Rotator Cuff Injuries
- Rehabilitation

Study Armgroups:
- {'label': 'Rotator Cuff Unloading Exercise Program', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients in this group will perform semi-closed kinetic chain elevation exercises, deltoid re-education exercises, assisted arm elevation and scapula control exercises.', 'interventionNames': ['Other: Rotator Cuff Unloading Exercise Program']}
- {'label': 'Rotator Cuff Loading Exercise Program', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients in this group will perform conventional exercises with focus on lateral rotation, medial rotation and arm elevation.', 'interventionNames': ['Other: Rotator Cuff Loading Exercise Program']}

Interventions:
- {'type': 'OTHER', 'name': 'Rotator Cuff Unloading Exercise Program', 'description': 'Patients in this group will perform semi-closed kinetic chain elevation exercises, deltoid reeducation exercises, assisted arm elevation and scapular control exercises.', 'armGroupLabels': ['Rotator Cuff Unloading Exercise Program']}
- {'type': 'OTHER', 'name': 'Rotator Cuff Loading Exercise Program', 'description': 'Patients in this group will perform conventional exercises focusing on lateral rotation, medial rotation and arm elevation.', 'armGroupLabels': ['Rotator Cuff Loading Exercise Program']}

Primary Outcomes:
- {'measure': 'Change from Baseline Quality of Life at 12 weeks and 1 month (follow-up) - The Western Ontario Rotator Cuff Index (WORC)', 'description': 'The Western Ontario Rotator Cuff Index (WORC) contains 21 questions distributed in five domains, each question can be scored between 0 and 100 on the Analogic visual scale. The final result of WORC varies from 0 to 2100, higher value indicates worse the quality of life of the individual.', 'timeFrame': 'Pre (baseline) treatment, post treatment (12 weeks) and after 1 month (follow-up)'}

Please estimate the sample size based on the assumption: 
Power of 80%, significance level of 5%, and a 15% drop-out rate
Sample size
        The sample size calculation was based on the smallest significant difference of 282.6 points from the WORC40 with an standard deviation of 400 points, a power of 80%, and a significance level of 5%. WORC was selected because it evaluates the quality of life of individuals with rotator cuff disease. Accounting for a 15% drop-out, 78 subjects will be included in the study, randomly allocated to two treatment groups: Rotator Cuff Unloading Exercise Programme (n=39) and Rotator Cuff Loading Exercise Programme (n=39).