Interrater Reliability and Precision of a Novel Hand Strength Assessment and Treatment Device: The GripAble.

Importance: Occupational therapy practitioners need modern tools for the assessment of maximal grip strength in clinical and remote settings.

Objective: To establish the (1) interrater reliability and (2) precision of the GripAble among three raters with different expertise in occupational therapy when testing healthy participants, and to (3) evaluate the relative reliabilities of different approaches to estimating grip strength (i.e., one trial, mean of two trials, and the mean of three trials).

Design: Measurement study.

Setting: Minnesota Translational Musculoskeletal and Occupational Performance Research Lab, University of Minnesota, Minneapolis.

Participants: Thirty volunteers, age ≥18 yr, without any hand problems.

Outcomes And Measures: Using GripAble, three occupational therapy raters with varied experience measured the maximal grip strength of the dominant and nondominant hands of all participants. Using the mean of three trials when testing grip strength with GripAble adds precision.

Results: GripAble has excellent interrater reliability (i.e., intraclass correlation coefficient > .75) and acceptable precision (minimal detectable change < 15%) among healthy adults.

Conclusions And Relevance: GripAble allows occupational therapy practitioners with different experiences to assess grip strength in healthy hands quickly, precisely, and with excellent reliability. Additional research is needed on its psychometrics in clinical populations and capacities in remote monitoring and exergaming. Plain-Language Summary: The results of this study show that grip strength, an important biomarker and commonly assessed construct in occupational therapy, can be evaluated reliably, precisely, and rapidly with GripAble. The use of GripAble by occupational therapy practitioners in clinical settings may help to build an infrastructure for remote measurements and exergaming interventions in the future.