Background and purpose: The purpose of this study was to determine the intrarater and interrater reliability of measurements of three clinical features of coordination based on the performance of the "finger-to-nose" test.
Subjects: Thirty-seven persons with traumatic brain injury (26 male, 11 female), aged 17 to 64 years (mean = 29.1, SD = 9.9), participated in the study.
Methods: Each subject's performance was videotaped and evaluated for the right and left upper extremities (UEs) (two trials each) with respect to the following variables: time of execution, degree of dysmetria, and degree of tremor (four-point ordinal ratings). One year later, five experienced physical therapists (including the original investigator) independently rated each patient's videotaped performance in the same manner as described above.
Results: Intraclass correlation coefficients (ICC[3,1]) for intrarater reliability were .971 and .986 and ICCs for interrater reliability were .920 and .913 for right and left UEs, respectively, for the time of execution. A generalized Kappa statistic of .54 was calculated for the scoring of dysmetria (both UEs), and Kappa statistics calculated for the scoring of tremor were .18 and .31 for right and left UEs, respectively. Interrater reliability was lower for the scoring of these variables and varied from .36 to .40 for dysmetria and from .27 to .26 for tremor (right and left UEs, respectively).
Conclusion and discussion: These results indicate that physical therapists demonstrate low reliability in assessment of the presence of dysmetria and tremor using videotaped performances of the finger-to-nose test. The results suggest, however, that therapists reliably measure the time of execution of this test. If the limitations associated with therapists' capacity for objective measurement of subjective phenomena cannot be overcome (eg, by establishment of more definitive scoring criteria for the measures of dysmetria and tremor), then therapists should seek alternative methods of evaluation of UE coordination.