Comparison of the upper extremity physical performance tests between asymptomatic adults with and without scapular dyskinesis

Abstract

Introduction Physical performance tests (PPTs) are screening tools widely available, easy to apply, and that can be performed in different environments and contexts. Scapular dyskinesis can be related to changes in glenohumeral angulation, acromioclavicular joint strain, subacromial space dimension, shoulder muscle strength/activation and humeral position/motion. Few studies were developed to understand the influence of aspects such as strength, stability mobility, and scapular dyskinesis on the scores of the upper extremity PPTs. Objective To compare the performance in the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST), Seated Medicine Ball Throw Test (SMBT) and Upper Quarter Y Balance Test (UQYBT) between asymptomatic adults with and without scapular dyskinesis. Methods Cross-sectional study with 20 asymptomatic individuals: 10 with scapular dyskinesis and 10 without scapular dyskinesis. The average number of touches, number of touches normalized by height, and power score in the CKCUEST, distance covered by the ball in the SMBT, reach in the medial, inferolateral, and superolateral directions, total excursion and composite score of the UQYBT were compared between both groups. Results No significant differences were found for all variables (p > 0.05). Small to moderate effect sizes were found for the scores of the CKCUEST (d = 0.16-0.78), a small effect size was found for the distance in the SBMT (d = 0.12), and small to moderate effect sizes were found for the scores of the UQYBT (d = 0.02-0.43). The scapular dyskinesis group presented better performance in all tests. Conclusion The presence of scapular dyskinesis in asymptomatic individuals is not a factor related to worse scores in upper extremity physical performance tests.