The Correlation of Time of Cervical Flexion with Cervical Symptoms in Office Workers: A Cohort Study

Abstract Background: An increasing number of office workers complain of neck pain after extended smart phone use. We conducted this study to examine the correlation between the time of cervical flexion (CFI) during smart phone use and cervical symptoms of office workers in China.Methods: In this cohort study, 1791 individuals responded to an on line questionnaire. For our study, we included responses of 498 [27.8%] office workers. Excluded from the study were 1293 [72.9%] individuals including building workers, students, non-office workers, and those who did not complete the questionnaire. Participants completed an online questionnaire survey from May 29, 2019 to April 10, 2020. The (Neck Disability Index) NDI was used to evaluate cervical symptoms. Multivariable logistic regression, threshold saturation effect analysis, t-test, and Pearson’s chi-square tests were used to analyze the data. Results: We analyzed questionnaire results of the 498 office workers. The t-test showed no significant differences among the gender groups for age, working age, and NDI scores (P>0.05). Compared with other activities, smart phone use had no positive correlation with NDI scores (P>0.05), while low back pain had a strong correlation with NDI scores (P<0.05). When adjusting for age, working age, and low back pain covariates, CFI had a positive correlation with NDI scores. In addition, CFI had a curve line correlation with NDI-a monotone increasing relationship; the fold point was 6 (P<0.05).Conclusions: CFI had a positive curve line correlation with the NDI suggesting that office workers should limit CFI to a maximum of 6 hours to decrease cervical symptoms.