Test-retest Reliability of Unilateral and Bilateral Carrying Protocol Based on Joule’s Functional Capacity Evaluation

Abstract

Introduction: Load carriage is one of the most frequent manual material handlings in industrial settings. However, due to the biomechanical risk exposures, carrying could lead to work-related musculoskeletal disorders. Joule’s Functional Capacity Evaluation is an FCE system used widely in Malaysia in return-to-work programs to ensure work readiness and prevent re-injury. However, the literature regarding the test-retest reliability of the carrying protocols is minimal, leading to a questionable level of consistency. Therefore, this study aimed to investigate the test-retest reliability of the carrying protocols in Joule’s FCE. Methods: A cross-sectional study was conducted to evaluate test-retest reliability where the carrying protocol of Joule’s Functional Capacity Evaluation was used among healthy university students (N=30). The participants were asked to perform a retest of the carrying protocol after one week.Results: The ICC values for the carrying protocols were good for dominant unilateral carrying was (ICC: 0.82; 95% CI: -6.00 to 5.81), non-dominant carrying was (ICC: 0.74; 95% CI: -6.78 to 6.02) and bilateral carrying was (ICC: 0.85; 95% CI: -6.26 to 5.51). Bland and Altman’s plot indicated no visible distribution patterns of the differences without exceeding the 95% limits of agreement. The standard error of measurements (SEMs) was relatively small for all carrying protocols. Conclusion: The test-retest reliability of carrying protocols in Joule’s FCE was good. Future studies are needed to replicate this study in real patients to further verify the reliability for clinical settings.