Reliability, Standard Error of Measurement, Minimal Detectable Change, and Known-Group Validity of Modified Closed Kinetic Chain Upper-Extremity Stability Test in Swimmers

Context : Upper-extremity physical performance tests are essential to assess the functional status of athletes. The Closed Kinetic Chain Upper-Extremity Stability Test (CKCUEST) is widely used in sports. However, the psychometric properties of its modified version (MCKCUEST) in swimmers are unknown. We aimed to assess the reliability, standard error of measurement (SEM), minimal detectable change (MDC), and known-group validity of the MCKCUEST in swimmers. Design : Cross-sectional study. Methods : We included swimmers of both sexes, aged 12 to 60 years, with and without shoulder pain. Two assessments were conducted with an average interval of 10.37 (3.15) days between them. The MCKCUEST scores were reported as number of touches, normalized score, and power score. Reliability of the MCKCUEST was evaluated using the intraclass correlation coefficient (ICC) (3, 3), SEM, and MDC 95 . For known-group validity, we compared MCKCUEST scores between swimmers with and without shoulder pain. Results : Fifty swimmers participated in this study (54% men; 42% with shoulder pain). The MCKCUEST demonstrated excellent reliability (ICC = .90 to .98). The SEM ranged from 1.4 to 1.9 for touches, 5.36 to 7.4 for the power score, and 0.59 to 1.62 for the normalized score. The MDC 95 ranged from 4.0 to 5.3 for touches, 11.0 to 20.4 for the power score, and 1.64 to 4.49 for the normalized score. For known-group validity, the asymptomatic group achieved a greater number of touches (mean difference [MD]: 4.5; 95% CI, 0.6–8.4), power score (MD: 23.2; 95% CI, 2.1–44.3), and normalized score (MD: 2.3; 95% CI, 0.03–4.5) than the shoulder pain group. Conclusion : The MCKCUEST demonstrated excellent reliability for assessing swimmers and adequate known-group validity. The SEM and MDC values observed across all scoring methods were relatively small, indicating low measurement error and the ability of the test to detect meaningful changes in performance over time.