Cervicocephalic kinaesthesia: reliability of a new test approach

Relocating either the natural head posture (NHP) or predetermined points in range are clinical tests of impaired neck proprioception but memory might influence these tests. Three new tests, reasoned to be more challenging for the proprioceptive system, were developed. The objectives were to assess the reliability of all tests and whether the three new tests were more challenging for the proprioceptive system.

A test-retest design was used to assess the reproducibility and errors of all five tests. Twenty asymptomatic volunteers were assessed a week apart, using an electromagnetic movement sensor system, the 3-Space Fastrak. A measure of error magnitude was used to detect kinaesthetic sensibility. Comparison of the means and their corresponding dispersion were analysed descriptively. The between-day intraclass correlation coefficients (ICCs) were calculated and plots of mean differences between days 1 and 2 were conducted to estimate test reliability. Multivariate analysis of variance (MANOVA) and least significant difference (LSD) pairwise comparisons were performed to compare the test accuracy between different target positions.

ICCs were between 0.35 and 0.9, but plotting the data modified the interpretation in some tests. Relocating a NHP was easier when the trunk was in a neutral position than when pre-rotated (error 2.46 degrees (+/- 0.2 degree) versus 5.95 degrees (+/- 0.7 degree). Relocating a 30 degrees rotation position (error 5.8 degrees (+/- 0.6 degree) and repeatedly moving through a target (error 4.82 degrees (+/- 0.7 degree) was also difficult.

The new tests were more challenging than relocating the NHP but the reliability of tests relocating uncommon positions was questionable.