Validity and Between-Day Reliability of the Cervical Range of Motion (CROM) Device

Clinical measurement, validity and intrarater reliability study.

(1) To confirm the validity and assess between-day test-retest reliability of cervical spine motion measurements made with the cervical range of motion (CROM) device in flexion, extension, bilateral rotation, and bilateral side flexion; (2) to provide meaningful information to clinicians about the standard error of measurement and the minimal detectable change for the CROM device.

Range of motion is a common outcome measure used in the assessment of the cervical spine. The CROM device is one of the tools used to measure cervical range of motion in the clinical setting. However, its psychometric properties are not well established, especially for measurements taken on separate days.

Quasi-experimental design with 1 group comparison. Twenty healthy adults (9 men and 11 women) participated in this study. Cervical range of motion was simultaneously recorded with the CROM device and the Fastrak motion analysis system for all 6 cervical movements mentioned above. The CROM device was placed on the participant's head consistent with standard clinical procedures. Two Fastrak sensors were positioned with 1 on the forehead and 1 over the spinous process of the T6 vertebra. Test-retest reliability of measurements made with the CROM device was assessed, as well as its standard error of measurement and minimal detectable change, with measures taken on 2 separate days spaced 48 hours apart.

Values obtained by the 2 measuring devices yielded Pearson correlation coefficients ranging between 0.93 and 0.98. Test-retest reliability of measurements of cervical range of motion using the CROM was found to be good, with ICCs ranging between 0.89 and 0.98. The standard errors of measurement across the 6 movements ranged from 1.6° to 2.8° and the minimal detectable changes across the 6 movements ranged from 3.6° to 6.5°.

The measurements made with the CROM were shown to be reliable in all movement directions. J Orthop Sports Phys Ther 2010;40(5):318–323.doi:10.2519/jospt.2010.3180