• Physical Therapy Korea
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• v.9 no.3
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• pp.113-124
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• 2002

The objectives of this study was to investiage the effects of sitting posture on carpal tunnel syndrome. Carpal tunnel syndrome (CTS) continues to be one of the most widely publicized maladies of the cumulative trauma disorder. Many studies have reported a positive association between CTS and highly repetitive work, high force, and poor posture. High force and repetitive work have especially been associated with CTS, but the evidence for work being a primary cause of CTS is strongest when these factors are combined. In addition to carpal tunnel syndrome, hand, wrist, and other disorders are attributed to these work-related movements. Such disorders are referred to as repetitive stress injuries, cumulative trauma disorder, overuse syndromes, and chronic upper limb pain syndrome. Incorrect posture also may play a role in the development of CTS in people who work at a computer and other types of keyboards. The tendency to roll the shoulders forward, round the lower back, and thrust the chin forward can shorten the neck and shoulder muscles, compressing nerves in the neck. This, in turn, can affect the wrist, fingers, and hand. The treatment and prevention of carpal tunnel syndrome continue to be approached with a segmental view of the human body. For example, the most common ergonomic solution for carpal tunnel syndrome associated with keyboard use is to keep the wrists in a neutral position by using a wrist rest in front of the keyboard and good sitting posture.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.169-179
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• 2010

The aim of this study was to investigate occupational and individual risk factors and working conditions in relation to musculoskeletal symptoms in street cleaners. Investigation was conducted through a survey of 395 male street cleaners employed by the government office in Seoul, Gyeonggi and Chung-Nam from July to August of 2009. The control group was comprised of 143 male drivers and security guards. Risk factors for musculoskeletal symptoms in street cleaners were investigated by multiple logistic regression analysis and also evaluated ergonomic risk factors by assessing working conditions of 4 street cleaners. As a result of symptom questionnaires, all of the prevalent rates of musculoskeletal symptoms in street cleaners had significantly higher results than those of the control group(p<0.05). On binary logistic regression analysis of musculoskeletal symptoms, street cleaners showed significant higher odds ratio as 18.84(95%CI: 6.56-54.12) in the arm/elbow, 10.49(95%CI: 4.29-25.65) in the hand/wrist compared to the control group. Both absence of rest breaks and exposure to ergonomic risk factors showed to be important internal risk factors of musculoskeletal symptoms among street cleaners. The exposure levels of QEC(Quick exposures checklist) in street cleaners were revealed to be higher on the shoulder/arm, wrist/hand, and neck than back, or from stress. The findings appear to show that street cleaners were high-risk group of work-related musculoskeletal disorders. Therefore street cleaners require a holistic interventional strategy, including adequate arrangement of rest breaks, improvement of working tools and control of individual risk factors such as obesity and smoking.

• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.167-177
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• 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 Korean Society of Safety
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• v.10 no.4
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• pp.103-108
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• 1995

This study was performed to investigate a relationship between a biomechanical analysis of compressive force at L5/S1 and electromyographic analysis of erector spinae muscle during lifting task. In the experiment, isometric contractions at 25, 50, 75, 100%MVC for short duration and sustained isometric contractions at 50%MVC were performed. For muscle recruitment patten and compressive force analysis, rectified EMG amplitudes analysis and computerized biomechanical analysis were used. To achieve data, angles of neck, shoulder, elbow, wrist, hip, knee, ankle and length of body segments were measured. Results shows that trends of initial EMG rectified amplitude were similar to those of biomechanical calculation value and for sustained isometric contraction at 50%MVC EMG rectified amplitude of erector spinae muscle after 40seconds was increased up to level of 75%MVC. Based on the results of this study, biomechanical analysis should be supplemented considering muscle fatigue, and it is also suggested that work-rest cycle critera and the evaluation of back-pain injuries should include muscle fatigue.

• Journal of Korean society of Dental Hygiene
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• v.12 no.6
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• pp.1128-1137
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• 2012

Objectives : The purpose of this study was to identify the factors that affect working environment related musculoskeletal subjective symptoms among dental hygienists. Methods : The subjects in this study were 232 dental hygienists working at dental clinics and general hospitals in Daegu. The data has collected through the self-questionnaire survey from July 9th 2012 to July 31th. Results : 1. Musculoskeletal subjective symptoms were 85.3% in shoulder(right), 81.9% in neck, 74.6% in shoulder(left), 65.5% in wrist(right), 56.5% in lower leg(right). 2. Pain frequency of musculoskeletal subjective symptoms were the highest 24.7% in neck. Seeing the severity pain was the highest 9.0% in foot(left). The investigation of work interference related to substantially pain showed the highest 18.5% in wrist(right). 3. Musculoskeletal subjective symptoms correlated with general characteristics such as age, marital status, regular exercise and medical check-up(p<.05). 4. Musculoskeletal subjective symptoms correlated with working environments such as working career, the night treatment, the average daily number of patients handled, the average daily standing work hours, the regular rest, the major job in work place and physical burden(p<.05). Conclusions : The education or program on wrong working habits and bad postures of dental hygienists is needed to prevent musculoskeletal disorder.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.412-422
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• 2009

This study was conducted to assess exposure to musculoskeletal disorder(MSD) risk factors in hospital personnel who performed non-routinized work tasks. A tool ("PATH-KOSHA" version) was newly revised from PATH(Posture, Activity, Tools and Handling) method and uploaded into a personal digital assistant(PDA). The version was used, on a basis of direct-observation, to collect PATH data at the 2 hospital settings in different regions. Job analysis was performed to get various information (e.g., work and rest time, task type) as well. The data collected were visually checked for data cleaning and stored for future data analysis. A total of 1,992 PATH observations were made for 37 hospital workers. Exposure levels varied across 18 items of the MSD risk factors. The highest percent time spent on non-neutral postures was 53% for wrist deviation, followed by 47%(pinch grip), 35%(trunk posture), 23%(neck posture), and 20%(shoulder/arm posture). The highest percent time spent among hand activity level(HAL) variables was 55% for HAL-cat2 (HAL: 3.3 - <6.7). The percent time of items with respect to both loads with more than 5kg and contact stress was less than 4%. Vibration was not exposed in the study workers. Different aspects were discussed for findings. The study results showed that wrist deviation was highest in percent time spent on awkward posture while HAL-cat2 was highest in hand repetition. The study suggests that distal upper extremity posture and HAL should be primarily addressed and controlled in non-routinized work including the hospital settings.

• Journal of Biomedical Engineering Research
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• v.43 no.5
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• pp.361-368
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• 2022

The purpose of this study was to develop a hand rehabilitation training system for hemiplegic patients. We also tried to find out five hand postures (WF: Wrist Flexion, WE: Wrist Extension, BG: Ball Grip, HG: Hook Grip, RE: Rest) in real-time using multi-channel EMG-based deep learning. We performed a pre-processing method that converts to Spider Chart image data for the classification of hand movement from five test subjects (total 1,500 data sets) using Convolution Neural Networks (CNN) deep learning with an 8-channel armband. As a result of this study, the recognition accuracy was 92% for WF, 94% for WE, 76% for BG, 82% for HG, and 88% for RE. Also, ten physical therapists participated for the usability evaluation. The questionnaire consisted of 7 items of acceptance, interest, and satisfaction, and the mean and standard deviation were calculated by dividing each into a 5-point scale. As a result, high scores were obtained in immersion and interest in game (4.6±0.43), convenience of the device (4.9±0.30), and satisfaction after treatment (4.1±0.48). On the other hand, Conformity of intention for treatment (3.90±0.49) was relatively low. This is thought to be because the game play may be difficult depending on the degree of spasticity of the hemiplegic patient, and compensation may occur in patient with weakened target muscles. Therefore, it is necessary to develop a rehabilitation program suitable for the degree of disability of the patient.

• The Journal of Korean Medicine
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• v.38 no.3
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• pp.1-12
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• 2017

Objectives: To interpret the meanings of Ryodoraku data and to use it as diagnosis tool, study on relationship between Ryodoraku and autonomic nervous reaction (ANR) has to be preceded prior to disease studies. This study aims to observe the change of Ryodoraku characteristics with ANR caused by treadmill exercise via a feasibility study. Methods: The electric current at 24 Ryodoraku points(H1~H6 at left/right wrists and F1~F6 at left/right feet) and vital signs were measured at rest, immediately after the treadmill exercise test, and at later recovery times(10min, 20min, 30min, 60min, 120min after the exercise test). The calculated Ryodoraku scores (RSs) were analyzed using repeated ANOVA test. Results: The RSs in the wrist Ryodoraku points were significantly increased immediately after the exercise (p<.05) and at 10min recovery time (p<.01), and no significant differences were found during the rest of the experimental sets. To the contrary, the RSs in the feet Ryodoraku points showed less difference throughout all the measurement time. Conclusions: The Ryodoraku characteristics change more sensitively in the wrists than in the feet in accordance with the previously reported sweat gland responses of the treadmill exercise. This is the first feasibility study to observe the change of Ryodoraku characteristics caused by treadmill exercise, and it shows the Ryodoraku characteristics are in accordance with known ANS responses.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.249-258
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• 2009

The purpose of this study is to identify the factors influencing the musculoskeletal discomfort and the physical region related symptoms. The outcome of the study uses KOSHA Code H-30-2003 which defines possible symptoms into different categories. Symptom I, ll showing the highest occurrence rate in shoulder and neck regions and most of Symptom III, IV come from back region. Analysis of the factors influencing the musculoskeletal discomfort vary in different parts of the body. In the neck region, the discomfort related to rest and the computer keyboard. Gender affects the magnitude of pain in the shoulder region. Wrist pain is related to the chairs being used and back discomfort is influenced by shoulder exercise and the degree of rest taken. Physical fatigue due to work affects all the regions mentioned above. Conclusively, office workers are prone to the musculoskeletal discomfort due to their work environment. To alleviate this problem, the workers need to be educated with proper long-term musculoskeletal related health programs and exercise program containing various stretching methods. In addition, the effort to improve the variables in this study would help to reduce the rate of musculoskeletal discomfort.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.17 no.1
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• pp.24-28
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• 2011

Background: The purpose of this study is to make a grip strength checker to make people measure their grip strength easily, based on standardized grip strength checker chart. Method: In this study, we measured right hand grip strength of 80 women residents of Deajeon (women in their 30s to 60s, 20 in each) 2 times per day for 5days in same conditions from 20th of November 2010 to 24th of November. it was measured by Jamar Hydraculic Hand Dynamometer made lately to compare with the current measuring equipment. No matter how big their hands are, their hands were fixed at second level. Measured as they sit on a chair and let their shoulders gathered and not be rotated, let their arms be 90 degree, wrist and forearm be at the middle for the first time, and took another after they took a rest, and measured the average of the two. Result: There was not a meaningful difference between the current measuring equipment and the equipment made lately (p>.05). Conclusion: It is thought that the equipment made lately can be believed. In addition, we want people to realize their own grip strength easily by this study.