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.