• Physical Therapy Korea
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• v.27 no.4
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• pp.250-256
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• 2020

Background: Unstable surface-based core training can significantly enhance core strength, but no studies have compared the effects of balance pad- and sling-assisted exercises. Objects: To study the effects of unstable surface-based balance pad- and sling-assisted core strength exercises on muscle activity. Methods: Twenty male students aged 20-25 years participated in this study. The effects of three types of core strength exercises, performed with a sling or balance pad, on the activities of three muscles, i.e., the right musculus obliquus externus abdominis (EO), right erector spinae (ES), and right gluteus maximus (GM), were examined. Results: 1) In the glute bridge exercise, the percentage of maximum voluntary contraction of the EO, ES, and GM were significantly different between the balance pad- and sling-assisted exercises. The relative contribution of the ES and GM activities to all muscle activity were not significantly different between the two training types, whereas that for EO showed a significant difference. 2) There was no significant difference in the percentage value of maximum voluntary contraction (%MVC) among the EO, ES, and GM during the "leg-lifting with flat support" exercise, and there were no significant difference in the relative contributions between the two training types. 3) In the "side bridge leg separation exercise", the %MVC of the ES, EO, and GM were significantly different between the two training types. Conclusion: Sling training for core muscles was generally better than balance pad assist training. The majority of physiotherapy patients require core training. Our results could guide physiotherapists in the choice of targeted exercises for these patients.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.7
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• pp.41-51
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• 2020

This paper presents the development of a robotic system for rehabilitation of the trunk's ability to maintain postural control under different balance conditions. The system, developed with extensive input from rehabilitation and biomedical engineering experts, consists of a seat mounted on a robotic mechanism capable of moving it with four degrees of freedom (3 rotational and 1 translational). The seat surface has built in instrumentation to gauge the movements of the user's center of pressure (COP) and it can be moved either to track the movements of the COP or according to operator given commands. The system allows two types of leg support. A ground mounted footrest allows participation of legs in postural control while a seat connected footrest constrains the leg movement and limits their involvement in postural control. The design evolution over several prototypes is presented and computer aided structural analysis is used to determine the feasibility of the designed components. The system is pilot tested by a stroke patient and is determined to have potential for use as a trunk rehabilitation tool. Future works involve more detailed studies to evaluate the effects of using this system and to determine its efficacy as a rehabilitation tool.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.2
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• pp.29-36
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• 2016

Purpose : The purpose of this study was to find out the effects on muscle activations of serratus anterior and upper trapezius muscles when push-up plus exercise togu applied differently depending on the body part. Method : Thirty six volunteers took part in this study and we divided into three groups(upper arm togu group 12, leg togu group 12, upper arm-leg togu group 12). Each experimental group performed push-up plus exercise. All volunteers received a total of 18 exercise session over a 6 week period (three times per week). Exercise program was composed of serratus anterior and upper trapezius push-up plus exercise. Then we measured muscle activation of scapular stabilizer by electromyography. Repeated ANOVA was used to examine the effects of the intervention on each outcome measure. Result : After the six week intervention, there was a significant difference between the pre and 6 week in serratus anterior and upper trapezius muscle activity(p<0.05). After the six week intervention, there was a significant difference among the three group in serratus anterior muscle activity but no significant difference in upper trapezius muscle activity(p>.05). Conclusion : Serratus anterior and upper trapezius showed high muscle activity during push-up plus exercise. Therefore have a positive impact of scapular stabilizer. The larger the area of the unstable support surface, the larger muscle activity was larger of variation quantity.

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.1-8
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• 2012

The current paper presents a novel control strategy of a three-phase, four-wire Unified Power Quality (UPQC) to improve power quality. The UPQC is realized by the integration of series and shunt active power filters (APF) sharing a common dc bus capacitor. The realization of shunt APF is carried out using a three-phase, four-leg Voltage Source Inverter (VSI), and the series APF is realized using a three-phase, three-leg VSI. To extract the fundamental source voltages as reference signals for series APF, a zero-crossing detector and sample-and-hold circuits are used. For the control of shunt APF, a simple scheme based on the real component of fundamental load current (I $Cos{\Phi}$) with reduced numbers of current sensors is applied. The performance of the applied control algorithm is evaluated in terms of power-factor correction, source neutral current mitigation, load balancing, and mitigation of voltage and current harmonics in a three-phase, four-wire distribution system for different combinations of linear and non-linear loads. The reference signals and sensed signals are used in a hysteresis controller to generate switching signals for shunt and series APFs. In this proposed UPQC control scheme, the current/voltage control is applied to the fundamental supply currents/voltages instead of fast-changing APF currents/voltages, thus reducing the computational delay and the required sensors. MATLAB/Simulink-based simulations that support the functionality of the UPQC are obtained.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.105-112
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• 2019

Objective: The main purpose of this study was to investigate the effects of wearing an ankle weight belt while performing gait in water by focusing on the effect of using ankle weights have on the gait kinematics and the muscle activities for developing optimum training strategies. Method: A total of 10 healthy male university students were recruited for the study. Each participant was instructed to perform 3 gait conditions; normal walking over ground, walking in water chest height, and walking in water chest height while using ankle weights. All walking conditions were set at control speed of $4km/h{\pm}0.05km/h$. The depth of the swimming pool was at 1.3 m, approximately chest height. The motion capture data was recorded using 6 digital cameras and the EMG was recorded using waterproof Mini Wave. From the motion capture data, the following variables were calculated for analysis; double and single support phase (s), swing phase (s), step length (%height), step rate (m/s), ankle, knee, and hip joint angles ($^{\circ}$). From the electromyography the %RVC of the lower limb muscles medial gastrocnemius, rectus femoris, erector spinae, semitendinosus, tibialis anterior, vastus lateralis oblique was calculated. Results: The results show significant differences between the gait time, and step length between the right and left leg. Additionally, the joint angular velocities and gait velocity were significantly affected by the water resistance. As expected, the use of the ankle weights increased all of the lower leg maximum muscle activities except for the lower back muscle. Conclusion: In conclusion, the ankle weights can be shown to stimulate more muscle activity during walking in chest height water and therefore, may be useful for rehabilitation purposes.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.14 no.3
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• pp.280-287
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• 2007

Purpose: This study was done to identify effects of lumbar curve support on back pain and comfort during bed rest after transurethral resection of prostate (TURP). Method: A quasi-experimental design with a non-equivalent control group was used. All patients were diagnosed with benign prostatic hyperplasia and underwent TURP. Twenty participants were assigned to the experimental group and twenty to the control group. After TURP, the lumbar curve of patients in the experimental group was supported using gel pads for 6 hours while the control group received the usual care with the both leg straight. The intensity of back pain and comfort levels were assessed on immediate return to the unit and for six hours following TURP. Bleeding complications were detected from hemoglobin and hematocrit levels. Results: Support of lumbar curve was found to be significantly effective in reducing back pain. the need for analgesics was significantly less in the experimental group. Comfort levels were not significantly different between the two groups. There were no bleeding complications in either group. Conclusion: These results suggest that supporting of lumbar curve ameliorates back pain without causing an increased incidence of bleeding complications after TURP and this nursing intervention should help TURP patients to be more comfortable.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.11-18
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• 2017

PURPOSE: The purpose of this study was to examine the effects of sciatic nerve mobilization techniques on straight leg raising (SLR) and walking ability in elderly women aged over 65. METHODS: Seventy women aged over 65 were examined using SLR test and forty women were selected as subjects. They were divided into Group I (under $70^{\circ}$ of SLR test of both legs, n=20) and Group II (over $70^{\circ}$ of SLR test of both legs, n=20). Nerve mobilization was applied to both groups (three times a week for 4 weeks). SLR angle was measured using digital goniometer and walking ability was measured by step length, stride length, velocity, double support, using GAITRite System. After 4 weeks, paired t-test was used to compare the changes of SLR test and walking ability within Group I and Group II. RESULTS: In Group I, SLR test, step length, stride length and gait velocity were significantly increased but double support was significantly difference. In Group II, SLR test, step length and stride length were significantly increased but gait velocity was not significantly increased and double support was significantly decreased. CONCLUSION: This study showed that sciatic nerve mobilization techniques had positive effects on the SLR angle and walking ability in elderly women.

• Journal of the Ergonomics Society of Korea
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• v.33 no.4
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• pp.281-287
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• 2014

Objective: The objective of the study is to develop a portable assistance device to help elderly users reduce strain on the knee and leg muscle while the elderly are standing up. Background: The pose of standing up from a chair is a basic movement, but the elderly often have difficulty standing up due to their weak muscles. We focus on designing a solution that helps the elderly reduce physical problems and support them standing up. Method: This study consists of three parts. Part I explores the way to reduce the refrain of leg muscle while standing up from a chair. In the process of structural development, we found that the moment is minimized when user pushes down the armrests due to a decrease in the force acting on the center of mass. In part II, a user test of 20 participants was carried out to rank the order of comfort of two stimuli: the chair with fixed armrests and the chair with the four-link mechanism that we created-in three different ways; (1) to stand up without touching armrests, (2) to stand up by pushing down on fixed armrests, and (3) to stand up by pushing down on armrests and being supported by the mechanism. To examine the statistically significant differences among the rank means, a Friedman test was conducted. In part III, we analyze the results of the user test and interview feedbacks, focusing on establishing a design strategy from UPO and visualizing it in 1:1 scale. Results: In part I, we decided to develop the four-link mechanism. The bottom is lifted up as the link rises. In part II, based on the rank data, we empirically found that UPO was assessed as the most comfortable during the stimuli. The thigh angle is smaller and the bottom of UPO is separated from a seat. In part III, after assessing the results and feedbacks, we created a visualization strategy for UPO: light, friendly, and novel. Conclusion: The portable and non-mechanical UPO comprises a four-link system that lifts the user's hips while standing. It can help users avoid knee and leg muscle strain. Its universal design considers the elderly's difficulties. Application: In a future study, combining light and durable material in UPO is expected to increase its usability. And this study is an opportunity to design various types of standing assistance devices.

• Journal of the Korean Society of Physical Medicine
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• v.3 no.1
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• pp.27-37
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• 2008

Purpose : Today, it enjoys a sports and a leisure where the anterior cruciate ligament(ACL) injury patient increase. The knee joint is important means of human body movement and to do an important duty when it encounters ACL injuries of the knee joint and the many restriction follows in the life which is ordinary. When it is damaged ACL, it comes to determinate that ACL reconstruction and preservation treatment that the according to condition of ligament and knee joint. After ACL reconstruction, that is the fact which already becomes known the exercise treatment advances a recovery and to reduce a sequela. Methods : we researched the method of exercise treatment after anterior cruciate ligament reconstruction operation by journal of science direct and KISS in daecu university. Results : The representative exercise treatment is isometric exercise, isokinetic exercise isotonic exercise and complex exercise but what kind of exercise treatment most is effective, it revealed and support it was not. The method of exercise treatment is very various, so It causes a confusion made to the therapist and patients. So it executes once again it sought the kinetic therapeutic method which is efficient from this research and it tried to observe preceding research after ACL reconstruction. To operation a various the exercise treatments, operation only the treatment which is general compared to it was effective in muscular power and muscle functional improvement. But this like improve despite with the exercise treatment consequence which is continuous from research of most the pain leg compares to the health leg, it appeared the discrepancy which is a muscular power, a muscular endurance and a hypertrophy muscle etc, to the health leg or before operating 100% of muscular power to having gets the many therapy time was the recovery rate. Conclusion : Therefore after ACL reconstruction, it will become the many research continuously which is improve the muscle functional and ROM of the exercise treatment method and From therapeutic site of the patients it does to memorizes knowledge in advance about ACL injuries and the application the isokinetic treatment or exercise program are the set of necessary, frequency and amusement that considers complex what kind of therapeutic exercise becomes accomplished with the patient take care of attention.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.43-50
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• 2021

A Leg Mating Unit (LMU) is a device utilized during the float-over installation of offshore structures that include hyperelastic pads and mating part. The hyperelastic pads absorb the loads, whereas the mating part works as guidance between topside and supporting structures during the mating sequence of float-over installation. In this study, the design optimization of an LMU for the float-over installation of floating-type offshore structures is conducted to enhance the performance and to satisfy the requirements defined by classification society regulations. The initial dimensions of the LMU are referred to the dimensions of those used in fixed-type float-over installation because only the location and the number of LMUs are known. The two-parameter Mooney-Rivlin model is adopted to describe the hyperelastic pads under given material parameters. Geometric variables, such as the thickness, height, and width of members, as well as configuration variables, such as the angle and number of members, are defined as design variables and are parameterized. A sampling-based design sensitivity analysis based on latin hypercube sampling method is performed to filter the important design variables. The design optimization problem is formulated to minimize the total mass of the LMU under maximum von Mises stress and reaction force constraints.