Cervical motion in patients with chronic disorders of the cervical spine: A reproducibility study

Study Design. Test-retest of cervical motion in patients with chronic disorders of the cervical spine. Objectives. To determine the reproducibility of cervical motion and examine the feasibility of its representation by a single parameter. Summary of Background Data. Reproducibility of cervical motion findings has been largely limited to normal subjects, leaving a conspicuous void regarding the measurement error in clinical groups. Methods. There were 2 groups of 25 chronic patients with whiplash and degenerative changes of the cervical spine tested twice (4-7 days). Head movement was measured along the 6 directions, as well as during rotation out of flexion and extension (cervical degenerative changes only). Results. Compared to normal subjects, both groups had a 25% to 35% reduction in cervical motion. High intraclass correlation coefficients (ICCs) (range 0.8-0.92) were derived for all directions. The ICCs for rotation out of flexion and extension were low. The relative standard error of measurement ranged from 15% to 28% for all directions, whereas the corresponding scores of the total cervical motion excursion were 10.6 (cervical degenerative changes) and 13.6% (whiplash). Conclusions. Judged by the ICCs cervical motion, findings were reproducible. However, in view of the measurement error as well as the homogenous reductions, total cervical range of motion should be considered a suitable parameter for interpretation of cervical motion limitations in these patients.