Intra and interrater reliability and clinical feasibility of a simple measure of cervical movement sense in patients with neck pain.

Background: Pattern tracing tasks can be used to assess cervical spine movement sense (CMS). A simple clinical measure of CMS (tracing fixed figure-of-eight (F8) and zigzag (ZZ) patterns with a head mounted laser) has been proposed and assessed in asymptomatic subjects. It is important to determine if examiner ratings of the traces are reliable and feasible for clinical use in those with neck pain. We therefore examined the intra- and inter-rater reliability of rating video recordings of the CMS tasks, and the feasibility of undertaking the tests in clinic by comparing slow motion versus real-time video ratings.
Methods: Cross-sectional study examining neck pain subjects from a physiotherapy clinic. F8 and ZZ patterns traced with a head-mounted laser pointer at two velocities (accurate; accurate & fast) were videoed and later examined. Time (total time taken to complete the pattern), error frequency (number of deviations) and error magnitude (sum of deviations multiplied by distance from the central line) were measured. Two assessors independently evaluated the laser tracing videos in slow motion; a third rated the videos in real time. Intraclass correlation coefficients (ICC) and standard error of measurements (SEM) were calculated for intra- and inter-tester reliability, and feasibility.
Results: Twenty neck pain patient (13 women) videos were assessed. Intra-and inter-rater reliability was substantial to almost-perfect (ICC 0.76-1.00; SEM < 0.01-2.50). Feasibility was moderate to almost-perfect (ICC 0.54-1; SEM <  0.01-2.98).
Conclusions: Video (slow motion) ratings of time and errors for F8 and ZZ movement patterns in neck pain subjects showed high intra and inter-rater reliability. Achieving reliable ratings in clinic (real-time) appears feasible. Synthesising our results, the most reliable and feasible CMS ratings appear to be when the subject uses accurate rather than accurate and fast execution. The ZZ movement pattern may be superior to F8 in terms of rating. Time and error frequency for tracing F8 and ZZ as accurately as possible in determining CMS appears promising for use in clinic. Future research directions were identified.