• Proceedings of the ESK Conference
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• 1998.04a
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• pp.19.1-24
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• 1998

Designers often hesitate to decide the shape, size, and layout of a product. Though ergonomic principles and data are absolutely needed in this process, they don't have enough guidelines to refer. For the refrigerator designers, they also are not convinced of their decision: the vertical position of the freezing and refrigerating rooms, the height of shelves, the shape of door-handle, and etc. To support the refrigerator design, we applied several ergonomic methods to the evaluation of a refrigerator. EMG measurement was used to evaluate the load of user's lumbar muscle. Based upon the experimental EMG data, we developed a model to predict the relative load according to the height of refrigerator shelves. Two different layouts of a refrigerator, R/F and F/R style, were compared with the model. A three-dimenaional motion analysis method was used to evaluate the user's motion of using a refrigerator. Ten door-handles with the different shapes and positions were evaluated by tracking the rotations of the user's arm. Video protocol analysis was used to evaluate the user interface of a control panel in a refrigerator. Finally, we made several ergonomic design guidelines based on the facts found in this research and the anthropometric data of the Korean adults. The results of this study can be applied to the ergonomic design of a refrigerator.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.287-307
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• 1991

This study aimed at examining speech defects of openbite patients, which were analized in terms of formant frequency for vowels and word pronunciation length for consonants. In addition, the upper and lower lip (perioral m.) activity was tested by the EMG. The tongue force was measured by the strain gauge, and the speech discrimination test was carried out. One experimental group and one control group were used for this study and they were respectively composed of six female openbite patients and six normal-occlusion females. Eight monophthongs, two fricatives and two affricatives were chosen for speech analysis. Speeches of the above-mentioned groups were recorded and then analized by the ILS/PC-1 software. Four hundred most frequently used monosyllables were also chosen for discrimination score. Openbite patients showed the following characteristics: 1. Abnormality in case of /a/, $/\varepsilon/$, /e/, /i/ $F_2$ and /e/, /a/ $F_1$. 2. Significantly elongated length in their pronunciation of /h/ and $/C^h/$ and somewhat elongated length also in their pronunciation of /s/ and /c/. 3. Significant upper lip activity according to the EMG test during pronunciation of the bilabial consonants. 4. Relatively weak tongue force according to the strain gauge measurement. 5. According to the speech discrimination test, high rate of misarticulation in case of (a) initial /p/ /s'/ and /ts'/, (b) /a/,$/\varepsilon/$,/e/,/je/,/o/, $/\phi/$,/jo/,/u/,/we/, and /i/ (c) final (equation omitted).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.88-97
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• 2012

The muscle strengths in various postures are still used in the workplace, although mechanization and automation have been continuously accomplished. The aim of this study is to measure the maximum muscle strength and analyze the muscle fatigue during the various wrench jobs which are one of the upper limbs related works. Four hundreds and eighty five college students (243 males and 242 females) participated in this study. Twelve muscle strengths which are using for pulling, pushing, lifting and lowering the wrench with various postures are measured. For every moment, the muscle strengths for both hands were measured. In each measurement, five seconds averaged value and peak value were collected. The averaged value of preferred hand and non-preferred hand was compared. Also, the averaged value of opposite movement was compared through t-test. The fatigue of agonist for each movement was analyzed using EMG analysis. The result of this study can provide some basic information not only in designing the tools in work but also in selection, training and management of workers.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.119-124
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• 2003

Despite rapid technological advance and increased automation facilities, many jobs and activities in our living require manual materials handling(MMH). These include wide variety of activities such as moving things, lifting bags. boxes or cartons, etc. Many studies found that handle could affect on maximum acceptable weight of lifting, but there were few studies f3r the effects of work posture and coupling in lifting tote box. This study performed that ten male college students were required to lift a tote box with and without handle for three postures (bending, straight, right angle posture). From the experiment, following results were obtained. (1) MVC reduced maximum 23% by type of handle. (2) MVC was highest in straight posture, but was lowest in right angle posture. (3) As a result of ANOVA, MVC paid attention to posture and coupling. (p<0.01) (4) To all handle types, biceps brachii activity was increased in right angle posture. but reduced in straight posture. (5) To all posture, biceps brachii activity was most lively in no handle. The results of MVC measurement, subjective rating, EMG analysis, statistic analysis showed that maximum acceptable weight of lifting was influenced by type of handle and straight posture was more comfortable than other postures. Based on these results, it was concluded that acceptable weight of lifting has to differ for work posture and coupling.

• PNF and Movement
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• v.19 no.1
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• pp.1-8
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• 2021

Purpose: The purpose of this study was to determine how the position of tibial rotation affects peak force and hamstring muscle activation during isometric knee flexion in healthy women. Methods: Seventeen healthy women performed maximum isometric knee flexion at 30˚ with three tibial rotation positions (tibial internal rotation, neutral position, and tibial external rotation). Surface electromyographic (EMG) activity was recorded from the medial hamstring (MH) and lateral hamstring (LH) muscles. The strength of the knee flexor was measured with a load-cell-type strength-measurement sensor. Data were analyzed using one-way repeated analysis of variance. Results: The results showed that MH and LH activities and peak force were significantly different among the three tibial rotation conditions (p < 0.01). The post-hoc comparison revealed that the MH EMG activity in tibial neutral and internal rotation positions were significantly greater than tibial external rotation (p < 0.01). The LH activity in tibial external rotation was significantly greater than the tibial neutral position and internal rotation (p < 0.01). The peak force of the knee flexor was also greater in the external tibial rotation position compared with the tibial neutral and internal rotation positions (p < 0.01). Conclusion: Our findings suggest that hamstring muscle activation could be changed by tibial rotation.

• Journal of Korean Physical Therapy Science
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• v.29 no.1
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• pp.55-63
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• 2022

Background: This study investigated the effect of erector spinae and quadratus lumbar kinesio taping and support surface conditions on abdominal muscle activity during plank exercise. Design: Within-Group design. Methods: A total of twenty-three healthy men and women participated in this study. Abdominal muscle (both external obliques and internal oblique muscle) contraction was analyzed through EMG measurement with the presence or absence of kinesio taping applied to the erector spinae muscle and quadratus lumborum muscle during plank exercise and the difference between the support surfaces (stable surface and unstable surface) as variables. Abdominal EMG was attached to the right external oblique, left external oblique, right internal oblique, and left internal oblique. Results: The results showed that Abdominal left and right external obliques and internal obliques showed significant increases in activity when kinesio taping was applied to the erector spinae and quadratus lumborum muscles and unstable ground (p<0.05). Conclusion: In this study, we confirmed that the activity of the abdominal muscles was significantly increased during the plank operation in the state where the kinesio tape was attached. In addition, it was confirmed that the activity of the abdominal muscles was significantly increased during the plank operation on the unstable surface. These results suggest that in the state of kinesio tape attached and instability, plank motion has a positive effect on abdominal muscle activity.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.123-131
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• 2017

The purpose of this study was to investigate the effect of bodyblade training on pain and trunk muscle activity in patients with chronic low back pain. A sample of 30 subjects were recruited for this study. Bodyblade training group(n=10) was performed bodyblade training three times a week for six weeks, lumbar stabilization training group(n=10) was performed lumbar stabilization training three times a week for six weeks, and control group(n=10) wasn't performed any other training. For evaluation of trunk muscle activity, surface EMG was used and for evaluation of pain, VAS was measured. The results were as follows: trunk muscle activity, there was significant difference according to the measurement, pain, there was significant difference according to the measurement. From the results, bodyblade training is expected to be an effective intervention for patients with chronic back pain.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.173-181
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• 2021

Purpose : The purpose of this study is to compare muscle activity after applying two muscle energy techniques (MET) to subjects with forward head posture to see if the post isometric relaxation (PIR) technique is more effective than the reciprocal inhibition (RI) technique. Methods : The muscle activity was measured using EMG after applying the PIR and RI techniques to 30 adults at K College. Subjects were selected for forward head posture whose ear center was 2.5 ㎝ front of the center of the shoulder. EMG equipment was used to measure muscle activity, and the measurement sites were measured in cervical flexor and extensor muscles. The experiment period was performed once a week for a total of two weeks, and after the pre-measurement was performed for 5 minutes PIR and RI exercise. In the PIR technique, the head is tilted back in a sitting position, and the experimenter applies resistance with the same force for 7~10 seconds and repeats 3-5 times after rest. In the RI technique, in a sitting position, the subject gives the force to bend the head forward, and the experimenter applies resistance with the same force for 7 to 10 seconds, and repeats 3 to 5 times after rest. Results : The result is same as the following. In the comparison of muscle activity, there was a significant decrease in both PIR and RI at 1 and 2 weeks. And there was a greater decrease in muscle activity in PIR. There was no difference in the comparison of decrease in muscle activity at 1 week and 2 week. Conclusion : Both PRI and RI can be said to be effective in improving the function of the forward head posture in the neck muscles. Therefore, the selection of the two techniques in clinical practice should be appropriately performed under the judgment of experts according to the patient's situation.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1635-1638
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• 1997

A measurement of conduction veloctiy of the action potentials along the muscle fibres has been applied to various diagnosis. When we measure muscle fiber conduction velocity, it occurs that not only change of conduction velocity but alos inclusion of mipulse component by physiological and experimental reason. So, robuster time delay estimation algorithm than general methods[1] is needed to find correct time delay form these signals. In this paper we, propose new time delay estimation algorithms, robust in impulsive noise, by using characteristic of .alpha.-stable distribution whcih defines impulsive noise well. Then we apply proposed algorthms to measure muscle fiber conduction velocity and compare them with other studies.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.176-179
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• 2001

A portable bio-signal measurement system for 24-hours continuous health monitoring of the elderly and the disabled is presented. The measurement system has the functions of acquisition of various bio-signals such as ECG, EMG and EEG, wireless data transmission/receive and adjustment of parameters such as gain and cut-off frequency. The data is sent to a host computer or other device via a Bluetooth. The design targets of the developing system for volume and power consumption are $20{\times}30{\times}5(mm^3)$ and 8mW.