Comparison of Functional Stability of Shoulder Girdle between Individuals with Symmetric and Asymmetric Scapula

Background and Aim: Changes in the position of the scapula due to its multiple roles, including acting as a muscle binding site and stabilization in this area can reduce the physiological and biomechanical efficiency of the shoulder, which ultimately increases shoulder injury. Therefore, the purpose of this study was to compare the functional stability of shoulder girdle between asymmetric and symmetric scapula. Materials and Methods: This was conducted on 156 male students in Tehran who were selected by purposeful cluster and enrolled in the research after obtaining informed consent. Kibler test was used to examine the symmetry of the scapula; 78 subjects had symmetrical and 78 asymmetrical scapula. We used Davis and Y tests to evaluate the stability of the shoulder girdle. To study the difference between groups, an independent t-test was used at a significant level of P≤0.05 using SPSS software.  Results: The mean scores of the two groups in the Davis test were significant (P = 0.0001) and also there was a significant difference between the symmetric and asymmetrical scapular groups in the normalized scores of each direction and the combined score of each hand (P = 0.0001). Conclusion: Asymmetry of the scapular bones due to disruption of the position of the scapula, and consequently a decrease in functional stability and quality of the optimal function can be considered to predict shoulder injuries.