Dose-Response Relationships between Work-Related Musculoskeletal Neck Symptom and Physical Risk Factors (2 year follow-up study) / 대한산업의학회지

OBJECTIVES: To estimate the association of work-related musculoskeletal neck symptom and occupational risk factors, and to identify the dose-response relationships between work-related musculoskeletal neck symptom and physical condition. METHODS: Workers from four metal industry companies were enrolled in the study. General characteristics, psyhcosocial and physical risk factors and work-related musculoskeletal neck symptom were investigated by questionnaire in the baseline study. At the follow-up study 2 years later, the neck symptom was surveyed. Workers who did not complain neck symptom at baseline and complain at follow-up, and workers who did complain neck symptom at baseline and follow-up were defined as case. The adjusted odds ratios (ORs) of physical risk factors were estimated for these subjects. Additionally, subjects who did not change their work at follow-up were analysed. RESULTS: Among the cohort of 251, 199 (79.3%) were used in the analysis, of which 71 (35.7%) were classified as cases. The adjusted ORs and the ORs of the subjects who did not change their work were increased with exposure to the following kinds of work: 'repetitive', 'lift', 'push/pull', 'neck/shoulder (overhead/bend)', 'hand/wrist (bend/pinch)', 'trunk (twist/bend)', 'pressure point', and 'incentive work'. Finally, with increasing exposure to 'repetitive', 'lift', 'push/pull', 'awkward postures', 'pressure point', and 'incentive work', the risks of work-related musculoskeletal neck symptom were increased. CONCLUSIONS: Work-related musculoskeletal neck symptom was increased with increasing exposure time of certain physical risk factors, and a dose-response relationship was observed.

Reliability and Validity of Questionnaire for Assessing Physical Workloads / 대한산업의학회지

OBJECTIVES: The aims of the study were to make a questionnaire for assessing physical workloads and to evaluate its reliability and validity. METHODS: A total of 220 workers (foundry workers 30, large vehicle assemblers 30, shipyard workers 75, and automobile manufacturers 80) completed a self-administered questionnaire and took examinations for physical work capacity and working heart rate. We excluded data with insufficient responses or incorrect physical work capacity and working heart rate. Finally, the data of 154 workers (70.0%) were used for our study. In order to evaluate the reliability and validity of the questionnaire, we used statistical analyses including the scaling assumption test and a comparison with the objective tool for physical workload which was evaluated by working energy expenditure. RESULTS: The items of the questionnaire in the same categories had close distribution in the evaluation of the scaling assumption. The item internal consistency was 0.41-0.73 for posture factor, and 0.62-0.79 for non-posture factor. The item discriminate validity was 100%. Cronbach's alphacoefficient of the total items was 0.73 (0.58 for posture factor and 0.74 for nonposture factor). In the correlation between working energy expenditure and questions, general physical activity (p=0.008), proportion of the workday with hands above shoulder (p=0.002), proportion of the workday with trunk bent (p=0.028), proportion of the workday with awkward posture (p=0.048), sweating after work (p=0.006), total scales (p=0.003) and Borg scale (p=0.011) all had statistical significance. CONCLUSIONS: Our questionnaire for assessing physical workloads demonstrated statistically significant reliability and validity. But the questions for the proportions of the workday with sitting work posture and with static posture should be modified via a larger study.