Intertester reliability of the hand-held dynamometer for wrist flexion and extension.

This study was conducted to determine the intertester reliability of a hand-held dynamometer for the wrist flexor and extensor muscles. Using the break test on 20 healthy subjects, three testers obtained two measures of strength for each muscle group. The data were analyzed using the Pearson product-moment correlation coefficients, intraclass correlations, and an analysis of variance (ANOVA) for repeated measures. Our Pearson product-moment correlations ranged from 0.89 to 0.95 for the intertester reliability of the wrist extensors and 0.90 to 0.93 for the wrist flexors, whereas the intraclass coefficients were 0.91 and 0.85, respectively. Although these correlations were high, ANOVA tests revealed that significant differences existed between testers for both the wrist flexion and extension data (p less than .05). From these results we concluded that although the correlations between testers were good, ANOVA tests suggested that there was limited reliability between testers.