Effectiveness of the Spencer technique on pain, disability and range of motion in patients with frozen shoulder: A systematic review and meta-analysis with meta-regression of randomized controlled trials.

INTRODUCTION

Frozen shoulder (FS) is a disabling condition marked by pain and restricted mobility. The Spencer technique is a structured manual therapy protocol that has been used in clinical practice. However, evidence regarding its effectiveness remains inconsistent. This study systematically evaluated its effects on pain, disability, shoulder range of motion, and potential moderating factors.

METHODS

Following PRISMA 2020 guidelines, a comprehensive search of PubMed, Physiotherapy Evidence Database (PEDro), and Medline-Ovid was conducted up to September 2025. Sixteen randomized controlled trials involving 659 participants were included. Outcomes assessed were pain, disability, and shoulder range of motion (external rotation [ER], abduction [ABD], internal rotation [IR]). Random-effects meta-analysis, subgroup, sensitivity, and meta-regression analyses were performed.

RESULTS

The Spencer technique demonstrated positive effects compared with conventional physical therapies (CPTs) in reducing pain, improving disability, and range of motion, including ER, ABD, and IR. However, it did not show superiority over other manual therapies. Meta-regression identified the addition of muscle energy technique as a significant moderator associated with greater improvements in pain intensity (β =  -2.095, p = .012), disability (β =  -1.623, p = .001), and range of motion, including ER (β = 3.878, p < .001), ABD (β = 3.686, p < .001), and IR (β = 1.941, p = .009).

CONCLUSION

The Spencer technique provides clinical benefits compared with CPTs. However, it does not demonstrate significant superiority over other manual therapy approaches in patients with FS. Incorporation of muscle energy technique enhances its therapeutic effects. Future trials with long-term follow-up and stage-specific analyses are warranted to clarify treatment durability or optimize clinical application.