Reliability Analysis of In-person and Virtual Goniometric Measurements for Select Shoulder and Forearm Motions

Abstract

Background: Previous research on upper extremity range of motion has compared in-person to virtual measures for sagittal plane motions (flexion/extension) showing good-excellent reliability. Since upper extremity evaluation includes motion in all planes, it is important to assess whether transverse plane motion (rotation, supination, pronation) can be reliably measured during a virtual assessment.

Purpose: To evaluate the reliability (test/re-test inter-rater and intra-rater) of goniometric measurements of shoulder internal rotation and forearm pronation/supination obtained in-person and virtually.

Study design: Observational cohort, Reliability study.

Methods: Subjects 18-60 years of age with no upper extremity injuries were recruited for range of motion (ROM) testing in a standing position with measurements performed with a standard goniometer. Shoulder internal rotation was measured using the Hand-Behind-the-Back method and forearm pronation/supination were measured with shoulder adducted to the body and elbow flexed. Before in-person measurements were obtained, a static image of end range was captured using a mobile device with a camera. Within 10 days of the in-person measurements, clinicians measured the range of motion on the static image using the same standard goniometric methods as the in-person measurements. Inter-rater and intra-rater reliability were determined via intraclass correlation coefficients (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) at the 90% and 95% confidence level.

Results: The inter-rater reliability (ICC≥0.94) and intra-rater reliability (ICC≥0.91) for all in-person and virtual measurements were classified as excellent (SEM: 0.79-1.74°, MDC90: 2.12-4.06°, MDC95: 2.20-4.82°). When combining the three examiners' measurements for each motion, there was a statistically significant difference between in-person and virtual internal rotation (77.5±9.0° vs. 75.3±9.0°, p=0.001). The only statistically significant difference found between examiners occurred for the in-person measurement of pronation (examiner 3: 3.9° greater compared to examiner 1, p=0.044).

Conclusion: Virtual assessment compared to in-person goniometric measurements showed excellent inter- and intra-rater reliabilities (ICC >0.75). This suggests clinicians trained in goniometry can utilize this technique either in person or on a virtual platform. Level of Evidence 3b.

Keywords: goniometer; range of motion; reliability; virtual.

Figure 1.. The internal rotation hand behind-the-back angle depicted between the forearm and a vertical line.

Figure 2.. Internal rotation hand behind-the-back angle measured using the bubble goniometer.

Figure 3.. Position for pronation measurement.

Figure 4.. Position for supination measurement.