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.

Simulated pain and cervical motion in patients with chronic disorders of the cervical spine.

The primary objective of the present study was to determine how simulated severe cervical pain affects cervical motion in patients suffering from two distinct chronic cervical disorders: whiplash (n=25) and degenerative changes (n=25). The second objective was to derive an index that would allow the differentiation of maximal from submaximal performances of cervical range of motion. Patients first performed maximal movement of the head (maximal effort) in each of the six primary directions and then repeated the test as if they were suffering from a much more intense level of pain (submaximal effort). All measurements were repeated within four to seven days. In both groups, there was significant compression of cervical motion during the submaximal effort. This compression was also highly stable on a test-retest basis. In both groups, a significantly higher average coefficient of variation was associated with the imagined pain and it was significantly different between the two clinical groups. In the whiplash group, a logistic regression model allowed the derivation of coefficient of variation-based cutoff scores that might, at selected levels of probability and an individual level, identify chronic whiplash patients who intentionally magnify their motion restriction using pain as a cue. However, the relatively small and very stable compression of cervical motion under pain simulation supports the view that the likelihood that chronic whiplash patients are magnifying their restriction of cervical range of motion using pain as a cue is very low.