Background: Adhesive capsulitis (AC) is a painful, progressively stiffening shoulder disorder that is more common in people with diabetes. Conventional physiotherapy emphasizes pain relief and mobilization, and both progressive resistance training (PRT) and moderate-intensity aerobic training are plausible adjuncts, but they have not been compared directly. This pilot randomized controlled trial (RCT) compared PRT with aerobic training, each added to conventional physiotherapy, for shoulder pain and disability in diabetic AC.

Methods: In this two-arm, parallel-group pilot RCT, 30 adults with type 2 diabetes and AC were randomized 1:1 to conventional physiotherapy plus PRT (Group A, n=15) or conventional physiotherapy plus moderate-intensity aerobic training (Group B, n=15). Both groups attended three supervised sessions per week for six weeks (18 sessions). The only outcome scale was the Shoulder Pain and Disability Index (SPADI) total score (0–100; higher = worse), assessed at baseline, week 3 and week 6. The primary endpoint was the between-group difference in SPADI change from baseline to week 6. Analyses followed the intention-to-treat principle and used Welch’s t-test, baseline-adjusted ANCOVA, mixed-design ANOVA with Greenhouse Geisser correction, and Hedges’ g; all efficacy analyses were exploratory.

Results: All 30 participants had complete SPADI data (retention 100%; 95% CI 88.7–100). Groups were similar at baseline (SPADI 65.1 ± 7.0 vs 65.0 ± 8.7). SPADI fell by 36.4 ± 10.2 points in Group A and 25.9 ± 9.5 points in Group B, a between group difference in change of 10.5 points (95% CI 3.1 to 17.9; p=.007; g=1.04). After baseline adjustment, the week-6 difference was −10.4 points (95% CI −15.4 to −5.5; p<.001) and the week-3 difference was −4.4 points (95% CI −7.6 to −1.2; p=.009). The Group × Time interaction was significant (F(1.72, 48.08)=5.94, p=.007, ηp²=0.175). Every participant in both groups improved by at least 8 points; 15/15 versus 14/15 improved by at least 13 points, and 9/15 versus 2/15 achieved a reduction of 50% or more (exploratory). Estimates were stable across sensitivity analyses.

Conclusion: In this pilot data set, adding PRT to conventional physiotherapy was associated with greater SPADI improvement than adding aerobic training. The point estimate lies within the published minimal clinically important difference range (8–13 points), but the confidence interval is wide, follow-up ended at week 6, and the trial was not powered for efficacy. An adequately powered, multicentre RCT with longer follow-up is warranted.

KEYWORDS: Adhesive Capsulitis, Frozen Shoulder, Type 2 Diabetes Mellitus, Progressive Resistance Training, Aerobic Exercise, Shoulder Pain and Disability Index, Pilot Randomized Controlled Trial.