Measurement Repeatability and Reproducibility of Virtual Goniometry of a Set of Acquired Images in Youths with Arthrogryposis Multiplex Congenita.

Objectives: To evaluate the intra-rater repeatability and the inter-rater reproducibility of using a virtual goniometer to measure upper and lower extremity joint range of motion (ROM) in youths with arthrogryposis multiplex congenita (AMC).

Methods: Youths presenting with AMC aged 8 to 21 years old were recruited. ROM of the upper and lower limbs were assessed remotely during a teleassessment on a video-conferencing platform. Screen captures were taken and ROM were measured by two raters, two-weeks apart, using a virtual goniometer. Intraclass correlation coefficient (ICC) and associated 95% confidence interval (CI) were calculated to assess intra-and inter-rater repeatability and reproducibility.

Results: Nine participants were included with a median age of 15.9 years (range: 11.3 to 20.8 years). The overall intra-rater ICC was 0.997 (95% CI:0.996 to 0.997) for the first rater and 0.993 (95% CI:0.992 to 0.994) for the second rater. The inter-rater ICC ranged from 0.410 (95% CI:-0.392; 0.753) for forearm pronation to 0.998 (95% CI:0.996; 0.999) for elbow flexion.

Conclusions: Results of the current study suggest that virtual goniometry is reproducible and repeatable for the ROM of most joints. Future studies should evaluate procedural reliability and validity of the proposed method for youth with complex conditions.