Arm dominance does not influence measures of scapular muscle strength and endurance in healthy individuals

BACKGROUND PURPOSE: Scapular muscle performance is potentially influenced by arm dominance. The purpose of this study was to investigate the effect of arm dominance on clinical measures of scapulohumeral muscle strength and endurance. METHODS: Thirty-two healthy individuals between the ages of 30 and 65 years were recruited to participate. Scapular muscle strength of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) were recorded with a hand held dynamometer. One scapulohumeral isometric muscle endurance task was performed in prone. The order of testing (strength and endurance) was randomized for each individual. Dominant to non-dominant strength and endurance measures were compared with paired t-tests. RESULTS: Arm dominance was significantly higher for UT strength (p < 0.001) and endurance (p = 0.015). However, the differences between the dominant and non-dominant limbs were not beyond minimal detectable change values. CONCLUSION: It does not appear that scapulohumeral muscle strength and endurance is clinically different for the dominant and non-dominant limbs in a middle age healthy population.