• Fashion & Textile Research Journal
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• v.11 no.6
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• pp.911-917
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• 2009

The purpose of this study was to investigate muscle activity of the lower limbs when walking in jeans in order to obtain basic information for development of new jeans patterns with excellent movement adaptability. Using three types of jeans (basic, medium, and slim) with different ease on hip, knee circumference, and crotch length, and two different types of shoes, Electromyogram (EMG) of the lower limbs muscle was measured for four healthy subjects walking on treadmills and stairs. EMG of vastus lateralis, semitendinous, tibialis anterior and medial head of gastrocnemius muscles was measured. The muscle activity was assessed in RMS (Root Mean Square) value of the EMG. On the treadmill in sneakers, only the vastus lateralis muscle showed a significant difference in RMS value depending on patterns. Basic and medium jeans allowed higher muscle activity than trunks of slim jeans did. On the treadmill in high heels and slim jeans, the RMS values of all muscles were significantly smaller than in basic jeans, whereas no significant differences were shown while in trunks or medium jeans. On the stairs either in sneakers or in high heels, no significant differences were shown between all muscle activities for all types of jeans. On the treadmill, greater fatigue was induced in all muscles from walking in high heels than in sneakers for all jeans patterns. When walking on the stairs wearing either type of shoes, however, the effect of jeans pattern on muscle activities was different from muscle to muscle.

• Journal of muscle and joint health
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• v.17 no.1
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• pp.68-78
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• 2010

Purpose: This study was conducted to determine the effects of Tai-Chi exercise and self-help management program applying laughter therapy in patients with osteoarthritis. Methods: This quasi-experimental study recruited a sample of 61 patients with osteoarthritis (experimental group: 30, control group: 31) through the community healthcare centers located in Seoul and Kyung Gi area. The primary outcome measures included symptoms of osteoarthritis, basic physical performance, fatigue, and depression assessed before and after the study. The data were analyzed using SPSSWIN V. 12.0. Results: At the end of the six-week intervention, left shoulder flexibility (t=2.011, p=.049), 6m walking speed (t=3.639, p=.001), and right balance (t=-2.30, p=.025) were significantly improved in the control group. Fatigue (t=3.012, p=.004), stiffness (t=2,093, p=.041), right shoulder flexibility (t=2.138, p=.037), right balance (t=-2.065, p=.043), and 6m walking speed (t=2.683, p=.009) were significantly improved in the experimental group. Conclusion: A twice a week, 6-week tai-chi exercise self-help management program applying laughter therapy is effective in decreasing fatigue and stiffness. Osteoarthritis is one of common chronic diseases that the patients should be required to continue self management for the rest of their life. Therefore, there is a need to develop the more effective self-help management program and nursing intervention to motivate them to maintain their own self-help management.

• Physical Therapy Korea
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• v.28 no.3
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• pp.215-226
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• 2021

Background: Robot-assisted gait training (RAGT) is an effective method for walking rehabilitation. Additionally, the body weight support (BWS) system reduces muscle fatigue while walking. However, no previous studies have investigated the effects of RAGT with BWS on isokinetic strength of quadriceps and hamstring muscles. Objects: The purpose of this study was to investigate the effects of torque, work, and power on the quadriceps and hamstring muscles during RAGT, using the BWS of three conditions in healthy subjects. The three different BWS conditions were BWS 50%, BWS 20%, and full weight bearing (FWB). Methods: Eleven healthy subjects (7 males and 4 females) participated in this study. The Walkbot_S was used to cause fatigue of the quadriceps and hamstring muscles and the Biodex Systems 4 Pro was used to measure the isokinetic torque, work, and power of them. After RAGT trials of each of the three conditions, the subjects performed isokinetic concentric knee flexion and extension, five at an angular velocity of 60°/s and fifteen at an angular velocity of 180°/s. One-way repeated analysis of variance was used to determine significant differences in all the variables. The least significant difference test was used for post-hoc analysis. Results: On both sides, there were significant differences in peak torque (PT) of knee extension and flexion between the three BWS conditions at an angular velocity of 60°/s and 180°/s conditions. A post-hoc comparison revealed that the PT in the BWS 50% was significantly greater than in the BWS 20% and the FWB and the PT in the BWS 20% was significantly greater than in the FWB. Conclusion: The results of this study suggest that the lower BWS during RAGT seems to lower the isokinetic torque, work, and power of the quadriceps and hamstring muscles because of the muscle fatigue increase.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.55-62
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• 2013

The exoskeleton robot to assist walking of hemiplegia patients or disabled persons has been studied in this paper. The exoskeleton robot with degrees of freedom of 2 axis has been developed and tested for joint motion. The obtained EMG signal from normal person was analyzed and the control signal was extracted from it for convenient and automotive performance of assistance robot to help hemiplegia patient walks as normal person does. the purpose of using FES(Functional Electrical Stimulation) for hemiplegia patient's walk is to restore damaged body function by this, but this could give fatal electrical shock to patients by wrong use or cause quick fatigue in muscle by continuous stimulation. The convenient movement of hemiplegia patients with minimum muscle fatigue was looked possibly by operation of assistance robot exoskeleton using control signal. and the walking assistance exoskeleton robot seemed works more efficiently than using FES stimulator. The experiment in this study was performed based on usual motion in our life like walking, standing-up, sitting-down, and particularly feedback control system using Piezo sensor along with button switch was applied for smooth swing motion in walking. The experiment also shows that hemiplegia patients can move conveniently by using electromyogram signal of healthy leg for the operation signal of assistance robot system attached at damaged symmetrical leg.

• IE interfaces
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• v.15 no.1
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• pp.82-88
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• 2002

A study was conducted to develop user-centered kitchen furniture and workspace to reduce fatigue and to prevent housewives's disorders such as low back pain and musculoskeletal disorders from housekeeping activities. A questionnaire survey and interview were performed on 150 households those live in 32Pyung-type($105m^2$) apartment in Seoul vicinity. Also actual housekeeping activities for 24 hours were video-taped for further motion analysis. Results of the study revealed that housewives complained the inconvenience and small size of storage space, and worksurface height as the most important problems to be considered for redesign. And they responded, if feasible, sitting is preferred over standing while they are working. After adapting a sit/stand chair in the kitchen, a physiological experiment measuring heart rate(HR) and oxygen consumption($VO_2$) as response variables was conducted to examine the effects of sit/stand chair in reducing physiological demand during housekeeping activities. The results showed that working on sit/stand chair reduced energy expenditures by maximum of 30% and 31.0% in terms of HR and $VO_2$, respectively. Also rearrangement of kitchen structure based on motion analysis showed that walking distance during daily housekeeping activities can be reduced by 5.5% on the average. Hence, it is concluded that adapting a sit/stand chair in the kitchen could reduce fatigue and occupational disorders of housewives from extended housekeeping activities.

• Korean Journal of Occupational Health Nursing
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• v.9 no.1
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• pp.49-55
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• 2000

When standing, walking, or running for extended periods of time, fatigue occurs in the legs. Although there are many ways, to release tense or fatigued leg muscles, in the case that there is insufficient time to relax, an easy way to release leg fatigue is using an inclined step (about 3 minutes). This method was more effective than performing stretching exercises as studied. An experiment was conducted on a golf course in the Kangwon province in Korea. Subjects were chosen randomly and consisted of 5 females and 4 males golf caddies. Their main tasks consisted of pulling golf carts to the bottom of a hill for 8 to 10 hours and sometimes lifting and lowering golf clubs during the duration of one day. EMG was measured after work and after using the previously mentioned inclined Steps for the lower legs using ME3000P. This study investigated the types of inclined Steps which would be most effective and appropriate for golf caddies, whether sex difference had any influence existed between male and female workers. The results showed that a step with a $20^{\circ}$ angle was most effective for males and a step with a $25^{\circ}$ angle was most effective for females. Females showed faster recovery from fatigue than males. However, there were no statistical significance between males and females.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.530-536
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• 2013

This study aimed to analyze and compare results from psychological relaxations by using profile of mood state (POMS) and Malondialdehyde (MDA) level as a scale of oxidative damage before and after walking in the forest and on the street. 29 participations (15 men and 14 women) walked in the forest and on the street for 30 minutes of each for two days. The participations filled a questionnaire for POMS and conducted an heart rate variability test, oxidative damage test (MDA as biological marker through a urine test) before and after walking. To compare the psychological states after walking in the two difference places, walking in the forest showed statistically more meaningful results in the section of tension, depression, anger, fatigue, confuse and total mood disturbance (p<0.01) than walking on the street. According to the MDA results, a concentration of MDA showed significant increase after walking on the street (p=0.014). On the contrary to this, a concentration of MDA tended to decrease after walking in the forest (p=0.076). The study showed that the psychological states were more stable and oxidative damages were more decreasing after walking in the forest than walking on the street. In the conclusion, MDA would be biological indicator for assessing the effect of alleviation on the oxidative stress after walking in the forest.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.65-72
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• 2016

In this study, a fully active transfemoral prothesis with a knee joint is designed considering stair walking conditions. Since the torque at the knee joint required for stair walking condition is relative high compared with the one in normal walking condition, the proposed design has high torque generating mechanism. Moreover, the transfemoral prothesis is designed in compact size to reduce its weight, which is related to comfortable fit and fatigue of patients. Flat type BLDC motor is used for simple and compact structure and various components are used to generate required torque with target working angle and speed. The weight reduction of structure is carried out using optimization method after the initial design process is complete. The optimization is conducted under the load conditions of stair walking. The optimized design is validated via finite element analysis and experiments. As a result, the weight is reduced using topology and shape optimization but maintaining the safety of structure. Also the space efficiency is improved due to its compact size.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.188-202
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• 2004

This research was designed to investigate biomechanical aspects of the evolution based on the hypothesis of dynamic cooperative interactions between the locomotion pattern and the body shape in the evolution of human bipedal walking The musculoskeletal model used in the computer simulation consisted of 12 rigid segments and 26 muscles. The nervous system was represented by 18 rhythmic pattern generators. The genetic algorithm was employed based on the natural selection theory to represent the evolutionary mechanism. Evolutionary strategy was assumed to minimize the cost function that is weighted sum of the energy consumption, the muscular fatigue and the load on the skeletal system. The simulation results showed that repeated manipulations of the genetic algorithm resulted in the change of body shape and locomotion pattern from those of chimpanzee to those of human. It was suggested that improving locomotive efficiency and the load on the musculoskeletal system are feasible factors driving the evolution of the human body shape and the bipedal locomotion pattern. The hypothetical evolution method employed in this study can be a new powerful tool for investigation of the evolution process.

• Physical Therapy Korea
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• v.15 no.1
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• pp.38-45
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• 2008

This study investigated gait characteristics, kinematics, and kinetics in the lower extremities between two different shoe conditions (high heeled shoes (7 cm), and high heeled shoes with a total contact insert (TCI)) after lower extremity muscle fatigue. Although TCI shave been applied in high heeled shoes to increase comfort and to decrease foot pressure, no study has attempted to identify the effects of TCI in fatigue conditions. The purpose of this study was to determine the effects of walking in high heeled shoes with TCI after lower extremity muscle fatigue was induced. This study was carried out in a motion analysis laboratory at Hanseo University. A volunteer sample of 14 healthy female subjects participated. All in fatigue conditions, the subjects were divided into two groups. The muscle fatigue was induced by 40 voluntary dorsi- and plantar-flexion exercises and 40 heel-rise exercises of the dominant foot. Surface electromyography was used to confirm the localized muscle fatigue using power spectral analysis of three muscles (tibialis anterior, gastrocnemius medialis and lateralis). The results were as follows: (1) In muscle fatigue conditions, the use of TCI decreased the peak flexion angle of the hip joint significantly in the early stance phase (p<.05) and increased the peak hip flexion moment in the terminal stance phase (p<.05). (2) In muscle fatigue conditions, the application of TCI also increased peak hip power generation in the early stance phase and peak hip power absorption in the terminal stance phase (p<.05). (3) In muscle fatigue conditions, the use of TCI reduced the impact force significantly and increased the secondary peak vertical GRF. These findings suggest that the TCI may provide beneficial effects when muscle fatigue occurs for a high heeled shoe gait. Future research employing the patient population and various types of TCI materials are required to clarify the effects of TCI.