Accuracy of a Low-Cost 3D-Printed Wearable Goniometer for Measuring Wrist Motion

Wrist motion provides an important metric for disease monitoring and occupational risk assessment. The collection of wrist kinematics in occupational or other real-world environments could augment traditional observational or video-analysis based assessment. We have developed a low-cost 3D printed wearable device, capable of being produced on consumer grade desktop 3D printers. Here we present a preliminary validation of the device against a gold standard optical motion capture system. Data were collected from 10 participants performing a static angle matching task while seated at a desk. The wearable device output was significantly correlated with the optical motion capture system yielding a coefficient of determination (R-2) of 0.991 and 0.972 for flexion/extension (FE) and radial/ulnar deviation (RUD) respectively (p < 0.0001). Error was similarly low with a root mean squared error of 4.9 degrees (FE) and 3.9 degrees (RUD). Agreement between the two systems was quantified using Bland-Altman analysis, with bias and 95% limits of agreement of 3.1 degrees +/- 7.4 degrees and -0.16 degrees +/- 7.7 degrees for FE and RUD, respectively. These results compare favourably with current methods for occupational assessment, suggesting strong potential for field implementation.