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

Introduction: Neck pain (NP) is associated with sensorimotor impairments, including altered trunk-head coordination. Limited data are available on the reliability of such assessments and influence of visual feedback in individuals with NP. Relationships between trunk-head coordination performance and NP, dizziness disability levels, or NP onset (traumatic or idiopathic) remain unclear. Methods: This cross-sectional study evaluated intra- and inter-session reliability of accelerometer-based trunk-head coordination assessment in traumatic and idiopathic NP subjects. Assessments were conducted under both visual and non-visual feedback conditions. The latter was repeated twice on the same day and once more within a week. Head movement during the task, represented by Constant Error (CE), Absolute Error (AE), Sum of Absolute Errors (SAE), and Variable Error (VE) was analyzed for reliability. Differences between visual feedback conditions and pain onset, and correlations with the Neck Disability Index (NDI) and Dizziness Handicap Inventory (DHI) were examined. Results: CE, AE, and SAE of 19 NP subjects demonstrated at least moderate intra-session reliability. None of the error types reached moderate inter-session reliability. Visual feedback significantly reduced head movement errors for AE and SAE. Correlations between error types and self-reported outcomes were weak to fair and did not reach statistical significance. No significant differences emerged between traumatic and idiopathic NP groups. Conclusion: Accelerometer-based trunk-head coordination showed moderate intra-session but lower inter-session reliability, suggesting variability in performance over time in individuals with NP. Visual feedback improved trunk-head coordination. Performance did not appear to be influenced by levels of perceived disability, dizziness, or the origin of NP.