Investigation of the relationship between scapular dyskinesis with shoulder proprioception and stabilization in adolescent overhead throw athletes

Scapular dyskinesia is commonly observed in adolescent athletes due to excessive unilateral upper extremity function in overhead throwing activities in sports branches that involve repetitive shoulder movements. Accordingly, information regarding changes in shoulder proprioception and stabilization is not clear. The purpose of our study; to investigate the effect of scapular dyskinesia on shoulder proprioception and stabilization in adolescent overhead throwing athletes. Our study was conducted with adolescents and sedentary adolescents in volleyball, basketball and handball sports branches. Demographic information of the participants was recorded. The participants' scapular dyskinesias were evaluated with the Lateral Scapular Glide Test (LSGT) and Scapular Dyskinesia Test (SDT), their shoulder proprioception was evaluated with the laser cursor-assisted angle repetition test, and their shoulder stabilization was evaluated with the Upper Extremity Y Balance Test (UEYBT). A total of 89 volunteer adolescents, 36 of whom were women, were included in our study. 48 of the participants were athletes (13 volleyball, 22 basketball, 13 handball) and 41 were sedentary adolescents. LSGT results were observed in the scapular region in 2 of the volleyball players (15.4%), 3 of the basketball players (13.6%), 8 of the handball players (61.5%) and 7 of the sedentary group (17.1%). Dyskinesia was observed as positive. According to the SDT results, normal scapular rhythm was observed in 6 (46.2%) volleyball players, 14 (63.6%) basketball players, 3 (23.1%) handball players, and 27 adolescents (65.9%) in the sedentary group. When the laser cursor-assisted angle repetition test was examined, statistically significant differences were observed between the groups in the average values of all positions of the proprioception test: right arm 90o flexion, right arm 90o abduction, left arm 90o flexion and left arm 90o abduction (p<0,001; p=0,002; p<0,001; p<0,001, respectively). When the results of the Upper Extremity Y Balance Test were examined, statistically significant differences were observed in the mean values of the right superolateral, right inferolateral, left superolateral and right inferolateral reaching directions between the groups (p<0.001; p=0.004; p<0.001; p<0.001, respectively). When the relationship between scapular dyskinesia and shoulder proprioception and stabilization was examined, no statistically significant difference was observed between the groups. More comprehensive studies are needed in which both players in various overhead throwing sports branches and these players are compared with sedentary control groups and various parameters such as scapular dyskinesia, shoulder stabilization, shoulder proprioception, shoulder function and shoulder injuries are evaluated simultaneously. Keywords: Adolescent, scapular dyskinesis, proprioception, stabilization, athlete