This study analyzed symptoms of MSDs(Musculokeletal Disorders) associated with characteristics of smartphone usage based on questionnaire survey. This study also tried to identify their relationship based on the results from questionnaire survey. A total of 943 subjects participated for the survey. The results in terms of symptoms associated with smartphone usage were as follows; 1) 49.8% of respondents experienced symptoms associated with MSDs, 2) 35.9%, 34.0%, 22.1%, 21.7% and 20.9% of respondents had symptoms at shoulder, neck, elbow, wrist, and fingers respectively, 3) The effect of ‘daily time of data use’, ‘monthly costs’ for MSDs of respondents was significant. Specifically, this study has some significance since it tries to identify the relationship between MSDs symptoms and characteristics of smartphone usage. The results of the study can be good basis for better design and user guidelines of smartphone to prevent MSDs associated with smartphone usage.

This study tried to identify the problems associated with the posture to be analyzed and tried to suggest guidelines for MSDs(Musculoskeletal Disorders) evaluation based on working posture. A total of 50 jobs from 3 different types of industries(electronics, hospitals, automobiles) were used for MSDs evaluation study which was done by 6 observers. Two indexes were applied to identify the problem in this study which were percentage of agreement and counter-time-error rate. Specifically, ‘counter-time-error rate’ represented a degree of consistency in terms of selecting the posture to be analyzed time after time. Main results of the study were as follows; 1) The average percentage of agreement for representative posture for whole body was relatively higher than that for representative postures for individual body parts, 2) The counter-time-error rate(%) has been reduced as the evaluation process has repeated for the same job. 3) The counter-time-error rate(%) for electronics, hospitals, and automobiles were 63.4%, 61.2%, and 67.3% respectively. 4) The counter-time-error rate(%) for the job with the work cycle of 0.5 to 2 minutes were lower than that of the jobs with the work cycles less than 0.5 minute or greater than 2 minute. 5) The work cycles and the number of trials had significant effects on counter-time-error rate while the types of industries did not have significant effects on counter-time-error rate. Some guidelines could be prepared from the results of the study. Probably, there should have an extension in terms of form and matter for this study in order to have more practical output.

The validity of the results from observational methods such as RULA, REBA, OWAS has been one of major concerns due to their subjective characteristics in determining the posture of interests. There have been many studies regarding validity of the results from each checklist. However, most studies provided only fragmentary rather than comprehensive results in nature. This study specifically tried to analyze consistency of novice user based on intra-observer consistency and sensitivity of industrial types during MSDs(Musculoskekltal Disorders) evaluation with major checklists. In this study, twenty two novice subjects were participated to conduct MSDs evaluation for the forty five jobs from three types of industries(automobile, electronics, hospital). The main results for this study were summarized as follows; 1) The action level based on RULA was always higher than that from REBA and OWAS for all three types of industries., 2) The order of consistency from novice users was OWAS(72.7%(kappa=0.57)) RULA(54.3%(kappa=0.41)), REBA(41.0%(kappa=0.34))., 3) The percentage of agreement between 2nd and 3rd trials was higher than those between 1st and 2nd trials and between 1st and 3rd trials irrespective of industrial types during using RULA and REBA., 4) The average score of automobile industry was higher than those of hospital and electronics industries., 5) The types of jobs associated with five body parts(A1(Front), A2(Interior), A3(Rear), A4(Lower), A5(Door)) in automobile industry showed statistically significant differences in terms of MSDs scores for the body parts considered in each checklists.

The purpose of this study is to examine the prevalence of musculoskeletal disorders and ergonomic risk factors for workers of printing business. A self-reporting survey and task analysis using video camera were performed to identify ergonomic risk factors associated with musculoskeletal disorders. We used the OWAS, RULA, and REBA methods to quantify the risk factors, and the results show that the printing business have high risk of work-related musculoskeletal disorders.

Occupational illness analyses are used to identify common factors contributing to occupational illness and to give recommendations for illness prevention. We discuss safety and health management policies based on the present status of MSDS(Musculoskeletal Disorders) characteristics and the actual safety and health problems. These results can be used to develop more effective occupational safety and health management policies for the prevention of MSDS.