Could a Feedback Device Help Manage Work-related Shoulder Disorders?

Inclusion Criteria: 1. Adult (≧ 18 years) employed full-time (minimum of 30 hours per week). 2. Experiencing work-related shoulder disorders (WRSDs), with minimal score of 14 points on the for the abbreviated version of the Disability of the Arm Shoulder and Hand questionnaire (QuickDASH), stemming from a diagnosis of rotator cuff-related shoulder pain (RCRSP), shoulder osteoarthritis (SOA) or rheumatoid arthritis (RA) involving the shoulder. 3. Symptoms persisting for more than 6 weeks. Diagnosis-specific criteria: 1. RCRSP: diagnosis requires meeting three positive criteria, including the presence of a painful arc in abduction, a positive Neer sign, Hawkins-Kennedy test, or Jobe Test, pain with resisted humeral external rotation; 2. SOA: diagnosis based on clinical findings (e.g., activity-related pain, reduced range of motion particularly external rotation and function, worsening night/rest pain) and radiologic findings (e.g., osteophytes, joint space narrowing, subchondral sclerosis, cyst formations, and humeral head deformities); 3. RA involving the shoulder: confirmed diagnosis according to the American College of Rheumatology criteria. Both SOA and RA diagnoses will be confirmed by a physician. Exclusion Criteria: 1. clinical signs of a massive rotator cuff tear (e.g., pseudoparesis or pseudoparalysis, passive elevation intact but active limited to \<90°, without neurologic deficit); 2. acute traumatic rotator cuff tears, fractures, adhesive capsulitis (characterized by night pain, pain with sudden or unexpected movements, global loss of active and passive range of motion), or shoulder instability (evidenced by a combination of orthopaedic tests such as apprehension and relocation tests, Jerk, Kim and posterior tests, along with and clinical signs like neuromuscular function impairment, history of instability, lesion mechanisms, worries that their shoulder could dislocate during activities); 3. distal neurovascular symptoms (e.g., thoracic outlet syndrome, venous thromboembolism); 4. previous shoulder surgery; 5. corticosteroid injection administered within the past 3 months; 6. symptomatic acromioclavicular joint pathology; 7. currently receiving conservative management for their shoulder pain (excluding medication for RA and OA), 8. absenteeism from work (unable to work at least 30 hours per week or on sick leave).