Association of decreased physical activity due to the COVID-19 pandemic with new-onset neck pain in survivors of the Great East Japan Earthquake: a prospective cohort study

OBJECTIVES: The COVID-19 pandemic has forced many people to stay at home and to maintain social distancing. This study aimed to assess the association of reduced physical activity during the COVID-19 pandemic with new onset of neck pain (katakori) among a rural Japanese population living in areas damaged by the Great East Japan Earthquake (GEJE). DESIGN, SETTING AND PARTICIPANTS: This prospective cohort study has been conducted continuously since 2011 after the GEJE. This study used longitudinal data from 1608 adults who responded to the self-reported questionnaire before and during the COVID-19 pandemic. Changes in physical activity due to the COVID-19 pandemic were categorised into four groups: ‘no change’, ‘decreased by 20%–30%’, ‘decreased by half’ and ‘almost never go out’. Multiple logistic regression analysis was used to estimate the OR and 95% CI of the association between COVID-19 pandemic-related physical inactivity and new-onset neck pain. RESULTS: In total, ‘no change’, ‘decreased by 20%–30%’, ‘decreased by half’, and ‘almost never go out’ were reported by 9.2%, 27.7%, 31.2% and 21.9% of respondents, respectively. Among them, 9.8% reported new-onset neck pain. A significantly higher rate of new-onset neck pain was observed in participants who reported ‘decreased by half’ (adjusted OR 1.85, 95% CI 1.04 to 3.30) and who ‘almost never go out’ (adjusted OR 2.13, 95% CI 1.16 to 3.91), compared with those who reported ‘no change.’ CONCLUSIONS: Decreased physical activity has increased due to the COVID-19 pandemic and was significantly associated with new-onset neck pain among GEJE survivors.