COMPARISON OF SPENSER TECHNIQUE AND POST-ISOMETRIC RELAXATION ON PAIN, RANGE OF MOTION, AND FUNCTIONAL DISABILITY IN FROZEN SHOULDER PATIENTS

Background: Frozen shoulder, also known as adhesive capsulitis, is a common musculoskeletal disorder characterized by progressive pain, joint stiffness, and restricted shoulder mobility that significantly affects daily functioning. It typically occurs in middle-aged individuals and may persist for prolonged periods if not managed appropriately. Manual therapy interventions are widely used in physiotherapy practice to restore mobility and reduce pain. Among these, the Spencer Muscle Energy Technique and Post-Isometric Relaxation (PIR) are frequently applied; however, direct comparative evidence regarding their clinical effectiveness remains limited. Objective: To compare the effects of the Spencer Muscle Energy Technique and Post-Isometric Relaxation on pain intensity, shoulder range of motion, and functional disability in patients with frozen shoulder. Methods: A randomized comparative clinical trial was conducted involving 42 patients diagnosed with frozen shoulder. Participants were randomly assigned into two equal groups: Group A received the Spencer Muscle Energy Technique, while Group B received Post-Isometric Relaxation. Both groups underwent supervised treatment sessions three times per week for eight weeks, along with conventional physiotherapy exercises. Outcome measures included the Numeric Pain Rating Scale (NPRS) for pain assessment, the Shoulder Pain and Disability Index (SPADI) for functional evaluation, and goniometric measurement of shoulder abduction and external rotation. Assessments were performed at baseline, four weeks, and eight weeks. Data normality was assessed using the Shapiro–Wilk test, which indicated non-normal distribution; therefore, non-parametric statistical tests including the Mann–Whitney U test, Wilcoxon signed-rank test, and Friedman test were applied. Results: Both groups demonstrated significant within-group improvements across all outcome measures over the study period (p < 0.001). Between-group analysis revealed that Group A showed significantly lower NPRS scores at four weeks (mean rank 25.86 vs. 17.14; p = 0.008) and eight weeks (mean rank 26.29 vs. 16.71; p = 0.004) compared with Group B. Shoulder abduction also improved significantly more in Group A at eight weeks (mean rank 31.52 vs. 11.48; p < 0.001). No statistically significant differences were observed between groups for SPADI pain (p = 0.444 at 4 weeks; p = 0.177 at 8 weeks), SPADI disability (p = 1.00 at 4 weeks; p = 0.052 at 8 weeks), or external rotation (p = 0.610 at 4 weeks; p = 0.147 at 8 weeks). Conclusion: Both the Spencer Muscle Energy Technique and Post-Isometric Relaxation were effective in improving pain, shoulder mobility, and functional disability in individuals with frozen shoulder. However, the Spencer technique demonstrated comparatively greater effectiveness in reducing overall pain and improving shoulder abduction, suggesting its potential advantage as a targeted manual therapy intervention in frozen shoulder rehabilitation. Keywords: Adhesive Capsulitis, Muscle Energy Techniques, Pain Measurement, Range of Motion Articular, Rehabilitation, Shoulder Pain, Shoulder Joint.