Inclusion Criteria:  Shoulder pain due to rotator cuff tendinopathy lasting more than 6 months. Internal Rotation Resisted Strength Test positive. Test Item Cluster (Hawkins-Kennedy, painful arc, and infraspinatus test) positive.  Exclusion Criteria:  History of: tumors, metastasis, osteoporosis, shoulder fractures, shoulder luxation and/or instability, previous shoulder surgery, cervical radiculopathy, full-thickness rotator cuff tears, glenohumeral joint degeneration, inflammatory arthropathy, acromioclavicular joint arthrosis, and rotator cuff calcifications. Being treated by other physical therapy or medical treatment for their shoulder pain at the time of recruitment.