Establishing normative data on scapulothoracic musculature using handheld dynamometry.

CONTEXT Scapular strength deficits have been linked to shoulder dysfunction. OBJECTIVE To establish normative data on the scapulothoracic musculature in normal subjects using a handheld dynamometer. DESIGN Descriptive normative data study. SETTING Field research. SUBJECTS 172 subjects with varying levels of overhead activity. METHODS A handheld dynamometer was used to test the upper, middle, and lower trapezius; rhomboids; and serratus anterior. MAIN OUTCOME MEASURES A 2-factor ANOVA was performed for each of the muscles by activity level and unilateral ratio by activity-level analyses. Post hoc analysis included multiple pairwise comparisons, using the Dunn-Bonferroni correction method. RESULTS Activity level did not significantly affect the unilateral ratios: Elevation:depression was 2.5:1, upward:downward rotation was 1.5:1, and protraction:retraction was 1.25:1. A rank order from strongest to weakest was established through significant comparisons. CONCLUSION The unilateral ratios along with the rank order should be considered when discussing scapular rehabilitation protocols.