The relationship between chronotypes and musculoskeletal problems in male automobile manufacturing workers

Suwhan Kim; Won-Ju Park; Seunghyeon Cho; Dae-Young Lim; Yeongjae Yoo; Hyeonjun Kim; Wonyang Kang; Kyung Wook Kang; Jai-Dong Moon

doi:10.35371/aoem.2021.33.e26

The relationship between chronotypes and musculoskeletal problems in male automobile manufacturing workers

Ann Occup Environ Med. 2021 Aug 13:33:e26. doi: 10.35371/aoem.2021.33.e26. eCollection 2021.

Authors

Suwhan Kim¹, Won-Ju Park¹, Seunghyeon Cho¹, Dae-Young Lim¹, Yeongjae Yoo¹, Hyeonjun Kim¹, Wonyang Kang², Kyung Wook Kang³, Jai-Dong Moon¹

Affiliations

¹ Department of Occupational and Environmental Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea.
² Institute of Occupation and Environment, Korea Workers' Compensation & Welfare Service, Incheon, Korea.
³ Department of Neurology, Chonnam National University Medical School and Chonnam National University Hospital, Gwangju, Korea.

Abstract

Background: Previous studies have shown that morning types are less sensitive to pain. This study aimed to examine the relationship between chronotypes and musculoskeletal problems in workers with musculoskeletal burdens at work.

Methods: This cross-sectional study included 119 male production workers from a large automobile manufacturing plant. All the participants worked 2 shifts and worked on the automobile assembly line. Data were obtained using structured questionnaires, including the reduced Morningness-Eveningness Questionnaire (rMEQ), and musculoskeletal symptom questionnaire. Participants with an rMEQ score of 18 points or more were defined as morning-type workers (MTWs). Participants whose scores were less than 18 points were defined as neither-type workers (NTWs).

Results: The arithmetic mean age was 51.8 ± 5.3 years. MTWs and NTWs accounted for 35.3% and 64.7% of the total participants, respectively. Evening- and intermediate-type workers accounted form 6.7% and 58.0% of the participants, respectively. There was no significant difference in the health indicators when the MTW and NTW groups were compared. However, the musculoskeletal symptom questionnaire demonstrated a significant difference between the MTW and NTW groups. In the preceding year, the MTW group had significantly lower musculoskeletal pain and treatment ratios compared to the NTW group (35.7% vs. 62.3%, p = 0.005 and 14.3% vs. 32.5%, p = 0.031, respectively). After adjusting for variables, the odds ratio (OR) for musculoskeletal pain was significantly higher in the NTW group than in the MTW group (OR, 3.112; 95% confidence interval, 1.285-7.535; p = 0.012).

Conclusions: In this study, the musculoskeletal pain ratio was significantly lower for MTWs when compared to NTWs. Chronotypes could play an important role in work-related musculoskeletal disorders. Further, larger-scale, follow-up studies on chronotypes are required to assist in the prevention of musculoskeletal disorders in future.

Keywords: Automobiles; Circadian rhythm; Musculoskeletal diseases; Pain threshold.