Is there ‘trustworthy’ evidence for using manual therapy to treat patients with shoulder dysfunction?: A systematic review

by Daniel W. Flowers, Brian T. Swanson, Stephen M. Shaffer, Derek J. Clewley, Sean P. Riley

The primary objective of this review was to create a ‘trustworthy,’ living systematic review and meta-analysis for the application of manual therapy interventions in treating patients with shoulder dysfunction. Included studies were English-language randomized controlled trials published between 1/1/2010 and 8/3/2023, with searches performed in: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), CINHAL, ProQuest Nursing & Allied Health, EBSCO Medline, and PEDro. The population of focus included adults 18 years and older with musculoskeletal impairments related to shoulder dysfunction. Our primary outcomes included pain and region-specific outcome measures. We excluded trials, including participants having shoulder dysfunction resulting from surgery, radicular pain, instability/dislocation, fracture, lymphedema, and radiation. Our screening methodology was based upon a previously published ‘trustworthy’ systematic review protocol. This included the application of our PICOTS criteria in addition to screening for prospective clinical trial registration and following of prospective intent, as well as assessment of PEDro scores, risk-of-bias ratings, GRADE scoring, and examination of confidence in estimated effects. Twenty-six randomized controlled trials met our PICOTS criteria; however, only 15 of these were registered. Only three were registered prospectively. Two of these did not have discussions and conclusions that aligned with their primary outcome. The remaining single study was found to have a high risk-of-bias, meaning the remainder of the protocol could not be employed and that no randomized controlled trials could undergo further assessment or meta-analysis. The results of this systematic review indicate there are no ‘trustworthy’ randomized controlled trials examining the effectiveness of manual therapy interventions for the treatment of patients with shoulder dysfunction, as defined by the prospectively established methodology. Therefore, these findings signal that creating a ‘trustworthy,’ living systematic review on this clinically relevant topic is not yet possible due to a lack of ‘trustworthy’ randomized controlled trials.