Validity and reliability of Veloflex to measure active cervical range of motion in asymptomatic and symptomatic subjects

Background: Neck pain has a high annual incidence and decreases the cervical active range of motion (ROM). Clinicians use various methods to evaluate cervical range of motion (CROM) that some of them have also been proposed to give instant feedback. Accordingly, this study aimed to examine the validity and reliability of Veloflex (VF) to measure the CROM by comparison with the cervical range of motion (CROM) device, and to examine their test-retest reliability. Methods: Thirty-eight healthy and 20 symptomatic participants were evaluated. Cervical flexion-extension, side bending, and rotations were tested in two sessions, first by the CROM and VF and in the second only with the VF. To evaluate the concurrent validity and agreement between CROM and VF, Pearson correlation coefficient (r) and Bland-Altmann plots were used. Reliability were evaluated using intra-class correlation (ICC), standard error of measurement (SEM) and minimal detectable change (MDC). Results: CROM and VF showed excellent correlation for all movements (r > 0.960). Both devices provided small mean 'bias' (<= 1.29%) in all movements regarding CROM measures. The intra-rater and inter-rater reliability of the VF was excellent (ICC > 0.98). SEMs ranging from 0.72% to 2.38% and the MDC ranging from 1.22 degrees to 2.60 degrees in all participants. The results support the validity and reliability of VF to measure CROM. For its use, with a basic training is enough to get reliable measurements.