Reliability of scapular classification in examination of professional baseball players.

<bold>Background: </bold>Clinically evaluating the scapulothoracic joint is challenging. To identify scapular dyskinesis, clinicians typically observe scapular motion and congruence during self-directed upper extremity movements. However, it is unclear whether this method is reliable.<bold>Questions/purposes: </bold>We therefore determined the interrater reliability of a scapular classification system in the examination of professional baseball players.<bold>Methods: </bold>Seventy-one healthy uninjured professional baseball players between the ages of 18 and 32 years volunteered to participate. We used a digital video camera to film five repetitions of scapular plane elevation while holding a 2-pound weight. Four examiners then independently classified the motions on video into one of four types. Interrater reliability analysis using the kappa (k) statistic was performed for: (1) classifying each scapula into one of the four types; (2) classifying each scapula as being abnormal (Types I-III) or normal (Type IV); and (3) classifying both scapula as both being symmetric (both normal or both abnormal) or asymmetric (one normal, one abnormal).<bold>Results: </bold>We found low reliability for all analyses. In classifying each scapula as one of the four types, reliability was k = 0.245 for the left limb and k = 0.186 for the right limb. When considering the dichotomous classifications (abnormal versus normal), reliability was k = 0.264 for left and k = 0.157 for right. For bilateral symmetry/asymmetric, reliability was k = 0.084.<bold>Conclusion: </bold>We found low reliability of visual observation and classification of scapular movement.<bold>Clinical Relevance: </bold>Current evaluation strategies for evaluating subtle scapular abnormalities are limited.<bold>Level Of Evidence: </bold>Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]