Scapular kinematics and scapulohumeral rhythm during resisted shoulder abduction – Implications for clinical practice

ObjectiveTo offer a three-dimensional description of the scapular kinematics and scapulohumeral rhythm (SHR) in healthy subjects during quasi-static shoulder abduction. To analyze and compare the influence of loaded and unloaded conditions on scapula kinematics and SHR.DesignEleven subjects were analyzed using videogrammetry and the application of mathematical modelling during quasi-static shoulder abduction positions (intervals of ≈30°).Main outcome measurementsScapular kinematic data under unloaded and loaded conditions.ResultsThe scapula presented external rotation, upward rotation and posterior tilting during the studied movement. Analyzing the scapulohumeral rhythm, different behaviours were observed in the scapular movement planes. Loading condition increased scapular upward rotation and posterior tilt at 60° and 90° of abduction (p > 0.01).ConclusionsAnalyzed scapular kinematics and scapulohumeral rhythm showed differences between adopted loading conditions. The clinical applications of these findings are discussed.