NECK AND SHOULDER PAIN INTENSITY AND WORKSTATION-RELATED FACTOR, MONITOR, ARMREST, AND KEYBOARD: A ONE-YEAR COHORT STUDY

K. Nakatsuka¹, Y. Tsuboi^1,2, S. Murata^1,3, T. Oka^4,1, K. Saeki¹, T. Isa¹, R. Kawaharada¹, K. Uchida¹, K. Horibe¹, R. Goto¹, E. Perrein¹, R. Ono¹

Background: Among office workers, neck and shoulder pain are prevalent health problems. Pain prevalences of office workers were 55% for neck pain and 38% for shoulder pain. Pain is a physical problem that can increase medical costs and diminish work productivity. With computer work increasing, the impact of workstation-related factors (place or usage of monitor, armrest, mouse, and keyboard) on musculoskeletal problems have attracted attention in various fields related to workers health. In some experimental studies, workstation-related factors had a significant impact on neck and shoulder pain. However, those experimental studies were not conducted in real work environments. Therefore, it is difficult to conclude whether workstation-related factors have an actual impact on neck and shoulder pain in the real world. A few epidemiological studies investigated the relationship between individual workstation (e.g. monitor and keyboard position) and neck and shoulder pain. Nevertheless, in the real world, the workstation is consisted of comprehensive factors, for example, armrest, monitor, mouse, and keyboard.

Purpose: Our study aimed to investigate the association between comprehensive workstations and change of neck and shoulder pain among office workers.

Methods: This study is a 1-year cohort study from June 2018 to July 2019. The measurements were conducted at two times, June and July 2018 (baseline) and June and July 2019 (follow-up). In this study, 384 workers answered our questionnaires at baseline, 323 workers met all criteria at baseline, and 248 workers could be followed. Finally, the participants who met the criteria (had no trauma or disease) at follow-up were 244 (median age, 38 years; 87% men; follow-up: 79.5%). Workstations (armrest position, device type, monitor position, mouse position, and keyboard position) were investigated in terms of 13 items and judged as “adequate” or “inadequate.” Neck and shoulder pain were assessed using the numerical rating scale. In the statistical analysis, outcome variables were pain intensity at baseline and follow-up, while explanatory variables were: number of inadequate workstations, time variant, and their interaction terms. Linear mixed model analysis was conducted with adjustment for age, sex, working duration, education history, and BMI.

Results: In baseline, the mean of neck pain intensity was 1.42 (SD = 2.20) and shoulder pain intensity was 1.88 (SD = 2.49).  In the adjusted model, the number of inadequate workstations had a positive significant association with neck pain intensity (β = 0.16; 95%CI: 0.081-0.24). However, the interaction of time variant and workstation-related factors were not significantly associated (β = -0.058; 95%CI: -0.12-0.011). Moreover, the number of inadequate workstations did not have significant association with shoulder pain intensity (β = 0.16; 95%CI: 0.053-0.27) and the interaction of time variant and workstation-related factors were not significantly associated either (β = 0.025; 95%CI: -0.054-0.10).

Conclusion(s): The workers with more inadequate workstation-related factors (armrest position, monitor position, device type, and keyboard position) had higher neck pain intensity from baseline through follow-up.

Implications: Our findings suggest that the modification of workstations can contribute to improving neck pain among office workers.

Funding, acknowledgements: The authors declared no potential competing interests, with respect to the research, authorship and/or publication of this article.

Keywords: office worker, workstation, pain

Topic: Occupational health & ergonomics

Did this work require ethics approval? Yes

Institution: Kobe University

Committee: Medicine Faculty of Health Science

Ethics number: 488-3