Correlation Between Scapular Dyskinesis Test and Lateral Scapular Slide Test in Scapular Assessment

OBJECTIVES: Alterations of the normal position or any abnormal motion of the scapula during active motions of shoulder is termed Scapular Dyskinesis (SD). SD is quite common in overhead athletes with or without shoulder pain. In addition to overhead athletes, SD has also been identified in healthy, asymptomatic individuals. Although there are several proposed methods to identify SD, there are two common methods used in clinical practice; as Lateral Scapular Slide Test (LSST) and Scapular Dyskinesis Test (SDT). SDT was developed as a dynamic functional test after the development of LSST which is a static measurement. SDT has also relatively higher reliability than LSST. In the 2013 consensus statement from ‘scapular summit’, SDT was recommended as a simple and reliable method for scapular assessment because of being a dynamic functional assessment method. The purpose of this study was to investigate the correlation of these two observational tests in asymptomatic population METHODS: Eighty-three healthy participants (mean age 21.74±2.3 years, 166 arms, 32 Female-51 Male) were recruited. Participants were eligible if they were ≥18 years of age, having active full shoulder motion, and who have no health problem to hinder them from participate. Individuals with symptoms produced by cervical spine motion, impingement syndrome, frozen shoulder, shoulder instability and a history of shoulder fracture/surgery were excluded. All participants performed SDT and LSST in a random order. Pearson's chi-squared test was used for statistical analysis. RESULTS: SDT detected SD in 44 participants (53%), LSST detected SD in 30 participants (36%). 20 participants (24%) determined as having SD in both tests. There was a moderate significant correlation between SDT and LSST (p=0.000, Pearson Chi-Square value=32.856, Phi=0.445). CONCLUSION: SDT and LSST have moderate correlation in identifying SD. In recent years, it is suggested that scapula shouldn’t be assessed in static positions/postures. Although both SDT and LSST show the presence of SD, they don’t evaluate SD in the same way because of the fact that LSST is a static assessment method whereas SDT is a dynamic method. Furthermore, SDT has higher reliability rather than other static assessment methods. Moderate correlation between these two tests may not always provide compatible outcome. For these reasons, we don’t recommend the use of LSST solely or instead of SDT in examination of SD. LSST’s complementary role in determination of SD with other assessment methods is arguable due to reliability issues. Optimal observational assessment algorithm in determination of SD should be investigated in future studies.