Effectiveness of pulse electromagnetic field therapy in patients with subacromial impingement syndrome: A double-blind randomized sham controlled study

Objective: In this study, we aimed to evaluate the early and late effects of pulse electromagnetic field therapy (PEMT) on muscle strength, quality of life, shoulder pain and function in the treatment of subacromial impingement syndrome (SIS). Materials-Methods: Eighty patients diagnosed with SIS by anamnesis, physical examination and magnetic resonance imaging were included in the study. The patients included in the study were divided into two groups as the PEMT group (n=40) and the sham PEMT group (n=40) using the closed envelope method. In the PEMT group, PEMT (30 min PEMT, 50 Hz frequency, 85 gauss) and exercise program (30 minutes, codman, range of motion, stretching, isometric and isotonic strengthening exercises) for 4 weeks, 5 days a week for 60 minutes; In the sham PEMT group, sham PEMT (30 minutes) and exercise program (30 minutes, codman, range of motion, stretching, isometric and isotonic strengthening exercises) for 4 weeks, 5 days a week for 60 minutes. Treatments were administered by the same therapist for a total of 20 sessions in both groups. Demographic data of the patients were recorded. Patient evaluation parameters were symptom duration, passive and active shoulder range of motion, Visual Analogue Scale (VAS), Constant Murley Score (C-MS), Shoulder Pain and Disability Index (SPADI), SF-36 Quality of Life Assessment Questionnaire, isokinetic dynamometer (it included measurement of muscle strength of the shoulder at three different speeds). Patient assessments were made before treatment (T0), after treatment (4.th week, T1), and at the 12. week (T2). SPSS 22.0 package program was used in statistical analysis and p<0.05 value was considered significant. Results: In our study, we found improvements in most parameters compared to baseline in the evaluations made after the treatment and at the 12th week in both groups. We found significant developments in all VAS parameters (rest, movement, night) C-MS total, C-MS pain, C-MS activities of daily living, in all SPADI parameters (total, pain, disability) and SF-36 sub-parameters of physical function, vitality, mental health, social function, pain and general health scores in the PEMT group compared to the sham PEMT group at the controls made at the end of treatment. In the 12th week evaluation, in addition to these parameters, in the PEMT group, we found statistically significant enhancement in active flexion and active abduction range of motion, C-MS ROM and physical role limitation and emotional role limitation scores of SF-36 sub-parameters compared to the sham PEMT group. Conclusion: In our study, we found that PEMT was superior to the sham PEMT group in terms of pain, range of motion, functionality and quality of life in the short and long term. However, high-quality randomized controlled studies with long-term follow-up and with large-scale are needed to confirm the effects of PEMT on patients with SIS. Key Words: Shoulder pain, Subacromial impingement syndrome, Pulse electromagnetic field therapy