Impairment Measures. Cervical mobility was measured using the Cer- vical Range of Motion device Several studies re- ported this evaluation tool to be reliable.44,45 Before measuring the cervical ROM, each subject prac- ticed two repetitions each of six motions (flexion, extension, right and
left side bending, right and left ro- tation) to increase the soft-tissue compliance of the neck. The tester then measured each subject’s active cervical ROM using the cervical ROM instrument. We summed the readings of six directions of neck movement and used the total cervical ROM as our outcome variable. Total cervical ROM has an advan- tage as a sensitive outcome measure compared with only one plane of motion because the direction of limited cervical ROM in individual patients can vary depending on the involved tissues. Some patients have difficulty turning their heads, whereas others may have limited extension. Using total ROM as the measure can reflect the amount of impairment from the cervical dysfunction in both cases.