The effect of neck torsion on joint position error in subjects with chronic neck pain.

The conventional cervical joint position error (JPE) test has been used as a measure of cervical afferent dysfunction in people with neck pain. However, head movement during the test may also stimulate the vestibular system. This study's objective is to investigate the effect of the modified JPE test with a neck torsion manoeuvre in order to determine if the new test is a more definitive measure of cervical afferent dysfunction. Twenty five volunteers with chronic neck pain and 26 healthy controls aged 18 to 60 were assessed on three tests of JPE: 'JPE conventional', 'JPE torsion' and 'Enbloc' (Control) using Fastrak and laser apparatus. The neck pain group was found to have significantly greater JPE in one conventional JPE test and almost all the torsion tests (p < 0.05). No differences in Enbloc(Control) tests were seen. Moderate to strong significant correlations were also seen between measures of JPE using the Fastrak and laser methodology (p ≤ 0.01). The results of this preliminary study indicate that 'JPE torsion' may be a more suitable test than 'JPE conventional' for cervical afferent dysfunction in people with chronic neck pain although future comparisons with people suffering from vestibulopathy is warranted to support these findings. Additionally, the laser method is comparable to Fastrak and may be useful as a clinical measure of repositioning errors for both conventional and torsion tests.