Scapular kinematics in athletes with and without rotator cuff tendinopathy: A systematic review

Context: Rotator cuff tendinopathy is one of the most frequently reported shoulder injuries in athletes of overhead sports. Abnormal scapular kinematics has been proposed as one of the contributing factors of rotator cuff tendinopathy in overhead athletes. Objectives: To review the literature on 3-dimensional scapular kinematics in overhead athletes with and without rotator cuff tendinopathy. Evidence Acquisition: Electronic databases (Cochrane Library, MEDLINE, Embase, and PubMed) were searched from inception to September 2017. In addition, the reference lists of the articles that met the inclusion criteria were also searched. We included studies that compared the changes in 3-dimensional scapular kinematics in athletes with and without rotator cuff tendinopathy. Two reviewers independently examined the quality of studies by using the modified Downs and Black checklist. Evidence Synthesis: A total of 9 studies (a total of 332 athletes, mean age 23.41 [2.62] y) were included in the final analysis. The methodological quality was low (modified Downs and Black checklist = 9/15). Our findings showed a consistent pattern of increased scapular anterior tilting and internal rotation in the dominant shoulders than the nondominant shoulders of athletes who participated in overhead sports. Athletes of overhead sports seem to demonstrate an increase in scapular upward rotation during arm elevation when compared with nonathlete individuals. However, there is no consensus on the scapular kinematics pattern in athletes with rotator cuff tendinopathy when compared with healthy controls. Conclusion: Findings demonstrated that changes in scapular kinematics were observed in overhead athletes. However, all the included studies were cross-sectional studies with small sample size and diverse sports participation, whether changes in scapular kinematics may contribute to rotator cuff tendinopathy in overhead athletes warrants more high-quality prospective studies.