Posture management for neck pain: identification and quantification of associated factors based on a multicentre cross-sectional study in China

Background: Neck pain (NP) is a leading musculoskeletal disorder globally. Posture management is crucial for its prevention; however, population-level evidence quantifying the associated factors in real-world settings remains limited. We aimed to identify and quantify threshold effects of key factors related to posture management associated with NP among Chinese adults. Methods: We conducted a multicentre, cross-sectional study across six Chinese cities. We collected data via face-to-face interviews using a questionnaire covering demographics, occupational factors, electronic device use, sleep, transportation, and exercise. Multivariable logistic regression identified factors associated with NP. We used restricted cubic splines to model nonlinear relationships, and applied the Akaike information criterion to determine dichotomisation cutoffs for continuous variables. Propensity score matching assessed the robustness of these associations, and subgroup analyses by sex and age assessed heterogeneity. Results: We included a total of 6,969 adults (≥18 years), comprising 2,662 (38.2%) with NP and 4,307 (61.8%) without. Identified associated factors included: computer use time for work ≥2 hours/day (odds ratio (OR) = 1.39; 95% confidence interval (CI) = 1.16-1.67, P < 0.001), smartphone use time for work ≥3 hours/day (OR = 1.21; 95% CI = 1.03-1.42, P = 0.022), smartphone screen height below horizontal eye level (OR = 1.16; 95% CI = 1.00-1.34, P = 0.043), and firm mattress (OR = 1.19; 95% CI = 1.04-1.37, P = 0.012) were associated with increased odds of NP. Sleeping time ≥7 hours/day (OR = 0.79; 95% CI = 0.69-0.89, P < 0.001), supine sleeping (OR = 0.87; 95% CI = 0.76-0.99, P = 0.039) and walking as the primary mode of transportation (OR = 0.80, 95% CI = 0.70-0.91, P < 0.001) were associated with decreased odds of NP. Conclusions: This study identified and quantified threshold effects of key factors associated with NP among Chinese adults, including electronic device use, sleep habits, and commuting patterns. These quantified thresholds offer actionable benchmarks for posture management of NP in clinical practice and public health interventions. Registration: Chinese Clinical Trial Registry: ChiCTR2400093567.