JKAOH Journal of Korean Academy of Oral Health

ISSN(Print) 1225-388X ISSN(Online) 2093-7784


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Original Article

Journal of Korean Academy of Oral Health 2017; 41(4): 255-261

Published online December 30, 2017 https://doi.org/10.11149/jkaoh.2017.41.4.255

Copyright © Journal of Korean Academy of Oral Health.

Assessment of risk factors for work-related musculoskeletal disorders of the neck in dental hygienists using video recording

Ka-Yeon Lee1, Jin-Ho Chun2

1Department of Dental Hygiene, Ulsan College, 2Department of Preventive Medicine, Inje University, Ulsan, Korea

Received: September 26, 2017; Revised: November 21, 2017; Accepted: December 10, 2017


Objectives: Work-related musculoskeletal disorder (WMSD) of the neck is a frequent health problem in dental hygienists. This study was conducted to assess the risk factors of neck musculoskeletal disorder (neck MSD) using video recording. Methods: The subjects were 50 currently working dental hygienists who agreed to participate in this study. A standardized questionnaire about WMSD (NIOSH/KOSHA) was distributed and video recording for neck posture and motion was performed between August and October 2012. The video recording was performed for 5 minutes using the reflective marker attachment on the 7th cervical vertebra. Major observation points included neck flexion angle, number of flexions, and length of static work when performing scaling and prosthetic procedures. Data were analyzed using MedCalc (ver 12.3.0, Mariakerke, Belgium), and the risk factors for neck MSD were assessed using simple and multiple variate analysis. Results: The mean age and work experience of the subjects were 27.9 years and 5 years respectively. The prevalence of neck MSD symptoms that met NIOSH/KOSHA’s criteria was 48%. The mean angle of neck flexion was 54.6o, mean maximum angle of flexion was 64.8o, and the mean time of static posture was 4.8 minutes during the 5 minutes recording interval. In the multiple logistic regression analysis adjusted by career, daily work time, and posture, the prevalence of neck MSD symptoms increased by 1.47 times (95% CI=0.24-9.48) with flexion >45o, and by 4.90 times (95% CI=0.91-26.4) when a static posture was preserved for >4.8 minutes. Conclusions: The measured angle of flexion and time of preserved static posture identified further serious than expected. Therefore, to reduce the risk of neck MSD, reasonable and practically applicable guidelines to correct neck bending and tilting, especially to relax the long static posture associated with flexion, should be prepared.

Keywords: Dental hygienist, Musculoskeletal disorder, Neck, Video recording