Objective: The purpose of this study was to determine the effect of functional scapular stabilization training compared with the standard physical therapy on function and pain in people with frozen shoulder syndrome (FSS).

Methods: In a single-blind randomized controlled trial, 86 people with FSS were randomly allocated into the intervention group (functional stabilization training [n = 43]) and control group (standard physical therapy [n = 43]) using block randomization for 12 weeks. The primary outcome measures were the Shoulder Pain and Disability Index and the numeric pain rating scale. The secondary outcome measures were range of motion (ROM), range of passive abduction, and coracoid pain test. All the outcome measures were carried out by an independent blind outcome assessor at baseline and at the end of 12 weeks.

Results: A significant group × time interaction effect was observed for the Shoulder Pain and Disability Index (95% CI, 2.95-16.74; P < .01) and the numeric pain rating scale (95% CI, 0.67-2.07; P < .01) at the end of 12 weeks. The external rotation ROM showed a statistical significance with a mean change of 7.8° and P value of <.01.

Conclusion: The present findings show that scapular functional stabilization training resulted in improvement of function, reduction in pain, and greater improvement in external rotation ROM in patients with FSS. Also, our study findings suggest the involvement of rotator interval and inferior soft-tissue structures as indicated by the coracoid pain test and range of passive abduction.