Abstract: Objective To evaluate the test-retest reliability and validity of the 3-dimensional Digital Goniometer for Cervical (3DDGC) in measurement of cervical range of motion. Methods 39 healthy participants were measured of cervical range of motion 2 times in 1 hour with 3DDGC by one observer, and with cervical range of motion (CROM) device once. The intraclass correlation coefficient (ICC) of test-retest and the Pearson correlation coefficient between devices were caculated. The measurement errors were evaluated with standard error of mean (SEM). Results The ICC was 0.89 of 3DDGC as the cervical rotation to the left, and it was 0.90-0.98 of the other directions, with the SEM of 2.07-3.85°. The Pearson correlation coefficient was 0.73-0.92, with the SEM of 1.66-3.17°. Conclusion 3DDGC is valid and reliable in test-retest in measuring cervical range of motion, which need more research clinically.

Key words: cervical vertebrae, range of motion, 3-dimensional Digital Goniometer for Cervical Motion, test-retest reliability, validity