Reliability of a laser beam device for the assessment of head repositioning accuracy in patients with chronic neck pain

Background: Laser beam devices have been widely used for the assessment of cervical proprioception. However, their reliability for the assessment of repositioning accuracy in patients with chronic neck pain requires further examination. Objective: Examination of test-retest and inter-rater reliability of a laser beam device for the assessment of cervical proprioception in patients with chronic neck pain. Methods: Twenty patients with chronic neck pain were conveniently recruited. The patients performed a head-to-neutral test at four different movement directions (flexion, extension, left and right rotation) and a head-to-target test at two different movement directions (left and right rotation) by wearing on their head a laser beam device. Five trials were performed at each direction. The assessment was performed by two different raters for examining inter-rater reliability. One of the raters reassessed the patients after a one-hour resting period to examine test-retest reliability. Results: Test-retest reliability was found to be moderate to good (intraclass correlation coefficient [ICC] .56-.81, standard error of measurement [SEM] 2.09-5.01 cm, smallest detectable difference [SDD] 5.79-13.87 cm). Inter-rater reliability was found to be moderate to excellent (ICC.59-.92, SEM 1.75-3.27 cm, SDD 4.85-9.05 cm). Conclusions: A laser beam device presented moderate to excellent reproducibility, however relatively high measurement error for assessing cervical proprioception in patients with chronic neck pain.