Reliability, validity, and clinical usability of a digital goniometer.
OBJECTIVE
The purposes of this study were to establish the validity of a digital goniometer (DG) prototype, determine the inter- and intra-rater reliability of the DG as compared to the universal goniometer (UG), and evaluate and describe the clinical usability of the DG as a measurement tool.


METHODS
Eighteen healthy patient models and 5 physical therapists volunteered to participate.


METHODS
Reliability testing of both the UG and DG was determined from the measurements of 5 therapists who performed 2 randomized, repeated measures of 5 joint motions on each of 6 patient models during 3 data collection sessions. To determine the validity of the DG, the investigators measured 8 randomly selected, computer-aided design (CAD) angles during each of the 3 data collection sessions. Physical therapist participants completed pre-/post-surveys to assess perceptions of clinical usability of the DG.


RESULTS
No statistically significant differences were found between devices. Comparison of the DG and UG demonstrated no difference for intra- or inter-rater reliability, with the DG yielding higher inter-rater ICC values for each of the 5 motions measured.


CONCLUSIONS
The DG has adequate concurrent criterion-related validity as a tool for assessment of joint ROM and equivalent inter- and intra-rater reliability to the UG. User surveys indicated that several of the novel features of the DG contributed to a higher likelihood that the device would be utilized by clinicians.
Carey
Mark A
MA
Achieve Physical Therapy & Sports Medicine, Grand Rapids, MI, USA.
Laird
Daniel E
DE
Murray
Keith A
KA
Stevenson
John R
JR
D000328:Adult; D053587:Arthrometry, Articular / Q000295:instrumentation*; D017076:Computer-Aided Design; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D034941:Upper Extremity / Q000502:physiology*; D055815:Young Adult