Intra- and inter-rater reliability of goniometric finger range of motion using a written protocol

Goniometric finger range of motion (ROM) is the most common outcome measure used for functional evaluation of finger joints, but its reliability is not well-evaluated. This study aimed to investigate intra- and inter-rater reliability of goniometric finger ROM using a written protocol for active, passive, and composite movements in healthy adults. The design was a single-center, cross-sectional, reliability study. Participants were 20 healthy adults (mean ± standard deviation, 36.4 ± 10.9 years). ROM for active, passive, and composite movements of the fingers was assessed by three occupational therapists with at least 5 years clinical experience in the field of physical disabilities. To standardize the measurement method used, we developed a written protocol, stabilized the wrist position, and trained the evaluators. Intraclass correlation coefficient (ICC) values were used for the reliability analysis. ICC (1,1) was used for intra-rater reliability. ICC (2,1) was used for inter-rater reliability. Hand-shaped heatmaps were used to summarize the reliability data. Most of the results (88.7%) showed moderate to good intra-rater reliability (ICC ≥ 0.50), while inter-rater reliability showed less (69.0%). Both intra- and inter-rater reliability showed no trends between dominant and non-dominant hands, type of movement, finger, or joint. Intra-rater reliability was relatively high and using a written protocol was beneficial. Inter-rater reliability tended to be lower, and differences in the physical structure of both raters and participants may have affected inter-rater reliability values.