This study compares head repositioning accuracy (HRA) using the cervical range of motion (CROM) device between individuals with cervical radiculopathy caused by disc disease and neck- healthy individuals. It also evaluates the test–retest reliability of the CROM device in individuals with CDD, and criterion validity between the CROM device and a laser in neck-healthy individuals with quantification of measurement inaccuracies. HRA differed significantly between individuals with CDD and neck- healthy individuals after rotation right and rotation left. 31% of individuals with CDD were classified as having impairment in HRA. The test–retest reliability of the CROM device in individuals with CDD showed ICCs of 0.79- 0.85, and SEMs of 1.4°- 2°. The criterion validity between the CROM device and the laser in neck-healthy individuals showed ICCs of 0.43- 0.91 and SEMs of 0.8°- 1.3°.
The results of this study support the use of the CROM device for quantifying HRA impairment in individuals with CDD in clinical practice; however, criterion validity between the CROM device and a laser in neck-healthy individuals was questionable. HRA impairment in individuals with CDD could be a significant factor to think about during rehabilitation and evaluated with the criterion established with the CROM device in neck-healthy individuals.