Trunk-head coordination in chronic neck pain, reliability, influence of visual feedback, and relationship to...

Neck pain (NP) is associated with sensorimotor impairments, including altered trunk-head coordination. Limited data exists on the reliability of assessments and the influence of visual feedback in NP. Relationships between trunk-head coordination performance and NP, dizziness, disability, or NP onset (traumatic or idiopathic) remain unclear.

Repeated-measures study to explore intra- and inter-session reliability of trunk-head coordination assessment in traumatic and idiopathic NP subjects, using a head-mounted accelerometer. Assessments were conducted under visual and visually constrained feedback conditions. The latter was repeated twice on the same day and once within a week. Head movement during the task was analyzed for reliability using Constant Error (CE), Absolute Error (AE), Sum of Absolute Errors (SAE), and Variable Error (VE). Differences between visual feedback conditions and pain onset, and correlations with the Neck Disability Index (NDI) and Dizziness Handicap Inventory (DHI) were examined.

CE, AE, and SAE of 19 NP subjects (age 53 ± 18 years; 13 females; NDI 23 ± 11%; DHI 16 ± 15%) demonstrated moderate (VE) and good (CE, AE, SAE) intra-session reliability. All error types reached moderate inter-session reliability. Visual feedback significantly reduced head movement errors for AE (0.07m/s²) and SAE (9.02m/s²). Correlations between error types and self-reported outcomes were weak to fair and not statistically significant. No significant differences emerged between traumatic and idiopathic NP groups.

Accelerometer-based trunk-head coordination showed moderate to good intra-session and moderate inter-session reliability, suggesting performance variability over time in NP subjects. Visual feedback improved trunk-head coordination. Performance was not associated with perceived disability, dizziness, or NP onset.