This study aimed to evaluate and compare the effects of high-intensity laser therapy (HILT) and shock wave therapy (SWT) on pain levels, shoulder mobility, and function in individuals with diabetic frozen shoulder (DFS). A total of 84 patients (aged 40–60 years) were randomly assigned into two groups: the shock wave group (G1; n = 41) and the HILT group (G2; n = 43). Shoulder functionality was measured using the American Shoulder and Elbow Surgeons (ASES) score, pain was evaluated using the visual analog scale (VAS), and shoulder flexion ROM was assessed with a goniometer. The participants in group 1 received one session per week of shock wave therapy for 8 weeks (at 5 Hz, 1.5 bar), while group 2 received two HILT sessions per week for 8 weeks, delivering a total energy of 1,080 J across three phases. Both groups also followed a prescribed exercise program. No significant differences were found between groups before the study. Post-treatment results showed a significant reduction in pain in both groups—49.38% in group 1 (P = 0.00) and 60.09% in group 2 (P = 0.00). ROM improvements were also significant: 25.74% in group 1 (P = 0.00) and 19.29% in group 2 (P = 0.00). Shoulder function improved significantly in both groups—96.66% in group 1 (P = 0.00) and 104.58% in group 2 (P = 0.00). When comparing the groups post-study, group 2 showed a significantly greater reduction in pain (VAS, P = 0.0001), and group 1 had a significantly greater improvement in shoulder ROM (P = 0.04), but there was no significant difference in shoulder function (P = 0.19). Overall, shock wave therapy was more effective for ROM improvement, while HILT proved superior for pain relief and shoulder function enhancement.
