Accuracy of an electrogoniometer relative to optical motion tracking for quantifying wrist range of motion

Abstract

Methods for capturing wrist range of motion (RoM) vary in complexity, cost, and sensitivity. Measures by manual goniometer, though an inexpensive modality, provide neither dynamic nor objective motion data. Conversely, optical motion capture systems are widely used in three-dimensional scientific motion capture studies but are complex and expensive. The electrogoniometer bridges the gap between portability and objective measurement. Our study aims to evaluate the accuracy of a 2 degree of freedom electrogoniometer using optical motion capture as the reference for in vivo wrist motion. First, a mechanical system constructed from two plastic pipes and a universal joint mimicked a human wrist to assess the inherent accuracy of the electrogoniometer. Simulations of radial/ulnar deviation (R/U), flexion/extension (F/E) and circumduction were evaluated. Second, six subjects performed three RoM tasks of R/U deviation, F/E, and circumduction for evaluation of the in vivo accuracy. Bland–Altman analysis quantified the accuracy. The mechanical experiment reported greater accuracy than the in vivo study with mean difference values less than ±1°. The in vivo accuracy varied across RoM tasks, with mean differences greatest in the F/E task (7.2°). Smaller mean differences values were reported in the R/U deviation task (-0.8°) and the circumduction task (1.2°).

Keywords:

• Measurement error
• goniometer
• wrist
• motion analysis
• kinematics

Acknowledgments

The authors thank Douglas C. Moore, Kalpit N. Shah, and Erika Tavares for their assistance throughout this study and the preparation of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Additional information

Funding

Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number [P30GM122732] (COBRE Bio-engineering Core).