• The Journal of Korean Physical Therapy
• /
• v.20 no.3
• /
• pp.45-51
• /
• 2008

Purpose: We evaluated the physical stress and pain to the musculoskeletal system of a dental practitioner when engaging in a dental scaling training exercise to prevent the development of musculoskeletal injuries. Methods: The 18 female (average age: 21$\pm$1 years) subjects were voluntarily picked from a group of juniors who have completed a one-and-a-half year training course that includes training exercises on the dentiform and on live subjects (other trainees). The test is done by measuring pain, activity, grip strength, and finger dexterity for each subject's hand and wrist. Before the test all subjects were confirmed to be right-handed and were informed of the study and its objective. Measuring was done before and after each subject performed dental scaling for one hour using the scaler and the curet. Results: Pain levels increased for both hand and shoulders, but hand pain was often greater than shoulder pain. Grip strength significantly declined in the right hand but not the left. For joint mobility, the flexion and the extension for the shoulder joint did not change; but the range of motion for both wrist joints significantly increased. For the dexterity test, both hands showed increased dexterity after the exercise. Conclusion: Dental scaling can affect the shoulders and wrists/hands. Therefore, a musculoskeletal injury prevention program for dental practitioners, which may include encouraging them to assume correct body posture when at work, must be sought. This study evaluated only the shoulders, wrists, and hands; but future studies should include areas such as the cervical area, the back, and the lower limbs.

• Journal of Agricultural Extension & Community Development
• /
• v.19 no.4
• /
• pp.1021-1039
• /
• 2012

Based on the ergonomic evaluation of workers in the domestic traditional Korean sweet manufacturer, one of the small scale agricultural product manufacturers, the purpose of this study is on estimating the specific works and muscles that have possibility of musculoskeletal disorder through an EMG experiment for quantitative evaluation. The method followed in an order: works that have musculoskeletal disorder risk were extracted through ergonomic assessment tools, RULA and REBA, and then EMG experiment on the postures was carried out with six healthy adult male patients. As an ergonomic evaluation result, work posture during the drying process had the greatest musculoskeletal disorder risk, and EMG activity in the cleansing work posture scored the highest among the drying, cleansing, and coating work postures. In particular in the drying work, relatively high EMG activities were shown in the two muscles in the lower body: biceps femoris muscle, and gastrocnemius, than any other muscles. Therefore, during the traditional Korean sweet workplace design in future, the workplace requires a posture that deeply bow wrist for a long time should be avoided.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.18 no.2
• /
• pp.141-148
• /
• 2008

To prevent musculoskeletal disorders(MSD) for dental hygiene students, who will potentially be at high risk of developing MSD while performing oral prophylaxis practice, an MSD prevention education program was designed and was offered to a group of dental hygiene students to find whether the program is effective. Before the program started and three months after the program ended, changes in the students' posture were filmed to observe them. The final subjects for analysis included 30 students in the experimental group and 41 students in the control group. To verify differences between the experimental and the control groups, repeated measures ANOVA was carried out before and after the program. After the education program, the experimental group's RULA scores for neck, left upper arm, right forearm, and wrist, RULA A score on both left and right side, RULA B score on left side, and total RULA score were significantly lowered during the operation on the upper jaw, compared with that of the control group. And, during the operation on the lower jaw, the experimental group's RULA A score, RULA B score, and total RULA score were very significantly lowered. The results of this study suggest the MSD prevention education program is effective in preventing the disorder. Thus, the program can be utilized as an education program for preventing MSDs during dental hygiene students' oral prophylaxis practice and clinical practice.

• Journal of environmental and Sanitary engineering
• /
• v.20 no.4 s.58
• /
• pp.59-68
• /
• 2005

This study was designed to provide basic data on preventive plans by affecting factors that have analysed on musculoskeletal diseases. The survey were conducted from July 1 to 30, 2004 among 600 hair dressers working in Seoul and Gwangju using self-administration questionnaire. The results of this study are summarized as follows: The pain experience rate of musculoskeletal diseases. in the last one year was $55.2\%,\;35.7\%$ of respondents answered they had pain on shoulders, $30.6\%$ had pain on legs and feet, $28.9\%$ had pain on waist, $26.8\%$ had hands, fingers and wrist, $22.3\%$ had pain on necks and $17.6\%$ had pain arms and elbows more than disease on necks, shoulders, arms and elbows, hands, fingers and wrists, waist, shoulders legs and feet. The prevalence rate of the last week was $40.3\%$. The prevalence rate in each body parts of the last week was $23.3\%$ on legs and feet, $21.2\%$ on shoulders, $20.8\%$ on waist, $14.9\%$ on hands, fingers and wrists, $14.4\%$ on necks, $9.3\%$ on arms. Based on the results above, working posture, job stress and physical burden from task are highly related with pain. In order to prevent musculoskeletal disease of hairdressers, working posture shall be improved and leisure opportunities to relieve stress, and health management education shall be provided.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.11
• /
• pp.1391-1398
• /
• 2011

Biomechanical analysis of arm motion during steering was performed using a motion analysis technique. Three-dimensional position data for each part of arm are fed into an interactive model combining a musculoskeletal arm model and the mechanical steering system to calculate joint angles and torques using inverse kinematic and dynamic analyses, respectively. The analysis shows that elbow pronation/supination, wrist flexion/extension, shoulder adduction/abduction, and shoulder flexion/extension have significant magnitudes. Sensitivity analysis of the arm joint motion with respect to seating posture and steering wheel configuration is carried out to investigate the qualitative influence of the seating posture and driver's seat configuration on the steering behavior.

• Journal of the Korean Society of Safety
• /
• v.27 no.3
• /
• pp.131-140
• /
• 2012

Though there might exist not a few differences between cyclic works and atypical works, many researchers have applied the same assessment techniques that used for repetitive works, which may result introduce bias in their conclusions. This research aimed to verify whether there exist non-negligible work characteristics and/or dissimilarity among works with different work nature and whether one of the most prevalent assessment techniques for assessing ergonomic hazards of musculoskeletal disorders, REBA, can be applied to atypical works. For a general hospital, an automobile repair shop, and two auto-part assembly plants which manufactures quite different parts, a questionnaire survey and field investigation and ergonomic assessment were carried out and analyzed statistically with reference to the 3rd Quantification technique. The results showed that there exist remarkable difference between physical factors in cyclic works and atypical non-cyclic works. As for repetitive work, body posture was significant factors affecting on musculoskeletal disorders while atypical works seemed to have none which implied that the necessity of taking psychosocial factors into account for assessment of hazards. Complain rate in repetitive works was highest shoulder, back, and neck or wrist in sequence. However, there existed no consistent trend in complain rate in atypical works. And, though weight of manufacturing objects was a common factor that can partly explain musculoskeletal complain, time duration was significant in atypical work whereas repeatability and body posture were significant in repetitive works. As being the results, to summarize, it could be said that application of conventional ergonomic assessment techniques regardless of repetitiveness would be fruitless, and that the necessity of a unique methodology focused on atypical non-cyclic works should not be neglected.

• Journal of the Korea Convergence Society
• /
• v.10 no.7
• /
• pp.335-342
• /
• 2019

The purpose of this study was to investigate the current status of work-related upper extremity musculoskeletal pain in baristas and to identify the elements that are related to pain. The questionnaires were distributed to 100 workers in 63 cafes on Jeonju city in Korea. As a result of investigating work related pain, 65.3% (n=64) answered "yes" to the question that had pain at least once a week, month, or year, or 34.7% (n=34) answered "no". Most of the workers were right-handed, and when they felt pain, they felt 25 to 50% of time per day. Especially, baristas reported that the use of porter filters during work and the tamping operation were the most painful. In conclusion, our study indicated that necessary to introduce and develop a program to prevent cafe worker disease, as well as need to future research to improve work environment and posture according to the characteristics of the cafe works.

• Journal of the Ergonomics Society of Korea
• /
• v.34 no.2
• /
• pp.167-177
• /
• 2015

Objective: The objective of this research is to develop evaluation checklist for personal office furniture and apparatus to shape comfortable and efficient worksite for workers' welfare improvement, productivity enhancement and labor force preservation, and to identify office work environment by applying the checklist. Background: Because most office workers work using computers in a sitting posture, the ratio of office workers among total musculoskeletal disorders patients is forecast to increase. In this regard, an effort to prevent and manage such musculoskeletal disorders is required. Method: This research developed evaluation checklist for personal office furniture and apparatus by examining 25 domestic and international ergonomic literature and anthropometric data. This research carried out a fact-finding survey targeting the A Office and B Office of one public agency using the checklist. Results: Although, the checklist items on desks, chairs, computers and other goods conformed to the checklist standards, the following items did not conformed: desk height adjustment, seat board depth adjustment, lumbar support depth, foot rest, wrist rest, mouse tray, headset, speaker phone and Bluetooth. Conclusion: The evaluation checklist for personal office furniture and apparatus and fact-finding survey results are considered to be used as basic data for office work environment and workers' welfare improvement. Application: The information drawn from this research can be helpful to manufacturers' design and manufacture of ergonomic furniture and apparatus.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.2
• /
• pp.113-120
• /
• 2013

This study was conducted to investigate the characteristics of smartphone usage and posture of users during using smartphone. A survey was conducted for 983 smartphone users to understand the association between smartphone usage and including subjective symptoms associated with musculoskeletal disorders. Main results from the survey were as follows; 1) 18.8% of the subjects experienced musculoskeletal symptoms at least at one of body parts. Specifically, 8.1%, 5.6%, 4.1%, and 11.3% of the subjects experienced musculoskeletal symptoms at neck, shoulder, elbow, and hand respectively, 2) The symptoms of musculoskeletal disorders were also associated with amount of text message and time for daily usage of smartphone. Specifically, relative risks of musculoskeletal disorders at hand/wrist/fingers in terms of "amount of text message" and "time for daily usage" for experienced user were 1.425 and 1.368 respectively to inexperienced user. This study identified 'amount of text message' and 'time for daily usage' as the major risk factors of smartphone usage in terms of musculoskeletal symptoms. The results of the study provided a good basis in order to remove or reduce the risks associated with musculoskeletal symptoms due to smartphone usage.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.6
• /
• pp.749-755
• /
• 2011

Objective: The purpose of this study is to assess the reducing effect of workload on developed electro-motion scissors. Methods: To achieve this, we measured the pressure distribution, Joint angle of fingers and JSI(Job Strain Index) for electro-motion scissors and hand-operated scissor in objective assessment and surveyed the uncomfortable degree in subjective assessment. Results: As a result, The peak of pressure in the electro-motion scissors was generally lower than the hand-operated scissors. JSI and overall joint angle of fingers for the electro-motion scissors were remarkably lower than the hand-operated scissors. Also, the subjective uncomfortable degree showed that the uncomfortable point of electro-motion scissors were generally lower than the hand operated scissors. Conclusion: The impact of reducing the work load as well as distributing the pressure around the hand by using electro-motion scissors during grapes pinching was confirmed.