No abstract

Background Proprioception deficits have previously been reported in patients with non-specific chronic neck pain (NSCNP), with a comprehensive and valid battery of tests still required. This study aimed to investigate the test-retest and inter-rater reliability of cervical proprioception in participants without NSCNP and to examine differences in proprioception between participants with and without NSCNP. Twenty participants without NSCNP and 20 age- and sex-matched participants with NSCNP were recruited. Proprioception tests were sequentially performed in random order, in four head-to-neutral movement directions (starting positions at mid-flexion, mid-extension and mid-right/mid-left rotation head-neck positions and end position at neutral head-neck posture) and two head-to-target movement directions (starting position from neutral head-neck posture and end positions at right and left 45° rotation), with a laser beam device secured onto their forehead. Participants performed all tests in sitting at a 1-m distance from a whiteboard. The average deviations of the laser beam mark from set targets marked on the whiteboard represented proprioception deficits. The two-way random, absolute agreement model of the intraclass correlation coefficient (ICC), the standard error of the measurement (SEM) and the smallest detectable difference (SDD) were used as measures of reliability. Between-group differences were examined with the independent samples t test. Results The reliability of the laser beam device in participants without neck pain varied from poor to good. The following tests demonstrated good reliability: test-retest ‘Head-to-neutral from flexion’ (ICC: 0.77–0.78; SDD: 5.73–6.84 cm), inter-rater ‘Head-to-neutral from flexion’ (ICC: 0.80–0.82; SDD: 6.20–6.45 cm) and inter-rater ‘Head-to-neutral from right/left rotation’ (ICC: 0.80–0.84; SDD: 5.92–6.81 cm). Differences between participants with and without NSCNP were found only in head-to-neutral from flexion (4.10–4.70 cm); however, those were within the limits of the SDD values of the HtN from flexion test. Conclusions The laser beam device can be reliably used in clinical practice only in the aforementioned head-neck movement directions, based on the findings of the present study. The between-group differences noted involved only the head mid-flexion to neutral test, possibly denoting proprioception deficits only in this movement direction, for reasons that require further evaluation.