Clinicians who think scapular dyskinesis is important are more likely to identify it in healthy individuals

Abstract

Objective: To assess interrater reliability of the visual scapular dyskinesis test among physical therapists and examine how clinician beliefs influence classifications of healthy shoulders. Methods: 104 physical therapists (≥3 years of experience) rated five videos of healthy volunteers performing weighted arm elevations, using a Yes/No classification for scapular dyskinesis. Participants completed a survey rating the perceived importance of scapular dyskinesis (1–10 scale), reported years of experience, and number of shoulder patients seen weekly. Fleiss’ Kappa quantified reliability, and a mixed-effects model evaluated associations between ratings and clinician factors. Results: Interrater reliability was low (Fleiss’ Kappa = 0.12); agreement ranged from 53.9% to 76.9%. Clinicians who considered scapular dyskinesis more important were more likely to classify it as present (OR = 1.42; 95% CI [1.14, 1.76]; p = .0015), while those seeing more shoulder patients weekly were less likely to do so (OR = 0.77; 95% CI [0.62, 0.94]; p = .021). Experience did not predict classification. Conclusion: The visual scapular dyskinesis test demonstrated poor reliability. Beliefs about its clinical importance and lower shoulder caseloads increased the likelihood of reporting dyskinesis. These findings question the test's diagnostic value and underscore the need for more objective assessment methods.