Test-Retest Reliability and Precision of GripAble: A Multipurpose Exergaming Device

Objective: GripAble is a novel upper limb motor function assessment and exergaming device. In this study, we aimed to (1) establish its test-retest reliability and precision and (2) determine which method of reporting (i.e., based on one, two, or three trials) yields the greatest reliability and precision when testing hand grip strength (HGS) in healthy-handed adults. Materials and Methods: Purposeful sampling was used to recruit a diverse sample of adults according to sex, age, and race. Data were collected during two sessions approximately 2 weeks apart. During each session, three trials of maximal HGS were taken bilaterally. Test-retest reliability was assessed using the intraclass correlation coefficient (ICC), and precision was assessed using the standard error of measurement and the minimal detectable change (MDC). Results: Thirty-six healthy-handed adults completed the study protocol. Across all methods of reporting, ICC values were ≥0.85. The highest reliability (ICC values for dominant and nondominant hands = 0.97 and 0.94, respectively) and precision (MDC% for dominant and nondominant hands = 12.9 and 18.2, respectively) were observed when the average of three trials was calculated. Conclusions: The GripAble device has excellent reliability and acceptable precision when used to assess maximal HGS in healthy-handed adults. Recording three trials and reporting their average yields the highest test-retest reliability and precision. Relevance: We present early evidence to support the use of GripAble as an HGS assessment device. Future research should include establishing HGS reference values and testing GripAble's reliability and precision in different clinical populations. Its efficacy as an exergaming intervention also warrants exploration.