J Korean Acad Oral Health.  2017 Dec;41(4):255-261. 10.11149/jkaoh.2017.41.4.255.

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

• Lee KY
• Chun JH

• KMID: 2400241
• DOI: http://doi.org/10.11149/jkaoh.2017.41.4.255

Abstract

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 54.6°, mean maximum angle of flexion was 64.8°, 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 >45°, 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.

Keyword

Dental hygienist; Musculoskeletal disorder; Neck; Video recording

MeSH Terms

Dental Hygienists*
Humans
Logistic Models
Neck*
Posture
Prevalence
Risk Factors*
Spine
Video Recording*

Figure

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  Fig. 1 Measurement of flexion angle of neck.

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  Fig. 2 Measurement of flexion angle according to the measurement time.

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  Fig. 3 ROC curve of average neck flexion angle whether neck musculoskeletal disorder symptom. Area under curve(AUC)=0.530, Associated criterion≤53.4.

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  Fig. 4 ROC curve of maximum neck flexion angle whether neck musculoskeletal disorder symptom. Area under curve(AUC)=0.530, Associated criterion≤59.

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  Fig. 5 ROC curve of length of static work for 5 minutes whether neck musculoskeletal disorder symptom. Area under curve(AUC)=0.540, Associated criterion≤4.8.

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