• 한국운동역학회지
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• 제23권3호
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• pp.271-278
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• 2013

The purpose of this study was to determine the effect of Pilates Reformer training on gait improvement of subjects with asymmetric pelvic rotation. The seven subjects with greater pelvic rotation in right swing were assessed twice, 4 weeks apart, during which there was submitted to a Pilates Reformer training (three 40 min session per week). The kinematic data consisted of pelvic rotation and flexion angle of hip and knee joint was measured during gait. In comparison between both leg swings, max, min and range values of pelvic rotation was not significantly difference. After training, range of pelvic rotation in right swing was significantly decreased, but in left swing was not. In comparison between both leg swings, the values of max of hip and knee joint angle was significantly difference. After training, max values of angle of knee joint in right swing was significantly increased, but in left swing was not. The result of this study revealed that Pilates Reformer training was effective in improving gait to symmetric pelvic rotation.

• 대한한방내과학회지
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• 제13권2호
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• pp.100-110
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• 1992

For an effective acupuncture treatment, the location of muscles around Sutaeumkyongkun and Suyangmyongkyongkun were researched and they were made contracted. The conclusion is as follows; 1. The contraction of muscles around Sutaeumkyongkun gives appearance of the postures ; free movement of thumb, abduction of extension of wrist, flexion and pronation of elbow, depression and abduction of girdle of superior limb, flexion, internal rotation and horizontal flexion of shoulder joint These postures all together consequently produces the action 'holding something in arms'. 2. The contraction of muscles around Suyangmyongkyongkun gives appearance of the postures; extension of metacarpophalangeal and interphalangeal joint of index finger extension and abduction of thumb, extension of wrist, extension and supination of elbow, adduction, elevation and upward rotation of girdle of superior limb, extension, abduction, adduction, internal rotation, external rotation, horizontal extension of shoulder joint, flexion and opposite rotation of neck. These postures all together consequently produces the action 'raising arms'.

• Structural Engineering and Mechanics
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• 제87권4호
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• pp.391-403
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• 2023

In this study, a new type of self-centering beam-column joint with tapered steel plate links is proposed. Firstly, mechanical property of the basic joint (with the prestressed steel strands only, to provide the self-centering ability) and the combined joint (with both the prestressed steel strands and tapered steel plate links, to provide self-centering and energy dissipation simultaneously) is theoretically analyzed. Then, three joints with different dimensions and combinations of tapered plate links are designed and tested through a series of quasi-static cyclic loading tests. Test results show that a nearly bilinear elastic moment-rotation relationship for the basic joint is obtained. With the addition of tapered steel plate links, typical flag-shape hysteretic curves are obtained, which indicates good self-centering and energy dissipating ability of the combined joint. By installing multiple tapered plate links, stiffness and bearing capacity of the beam-column joint can be enhanced. The theoretical moment-rotation relationships agree well with the test results. A simplified macro model of the proposed joint is developed using OpenSees, which simulates reasonably well its hysteretic behavior.

• Steel and Composite Structures
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• 제38권5호
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• pp.547-562
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• 2021

This paper aims to explore the mechanical behavior and moment-rotation model of blind bolted joints between concrete-filled double skin steel tubular columns and steel-concrete composite beams. For this type of joint, the inner tube and sandwiched concrete were additionally identified as basic components compared with CFST blind bolted joint. A modified moment-rotation model for this type of connection was developed, of which the compatibility condition and mechanical equilibrium were employed to determine the internal forces of basic components and neutral axis. Following this, load transfer mechanism among the inner tube, sandwiched concrete and outer tube was discussed to assert the action area of the components. Subsequently, assembly processes of basic coefficients in terms of their stiffness and resistances based on the component method by simplifying them as assemblages of springs in series or in parallel. Finally, an experimental investigation on four substructure joints with CFDST columns for validation purposes was carried out to capture the connection details. The predicted results derived from the mechanical models coincided well with the experimental results. It is demonstrated that the proposed mechanical model is capable of evaluating the complete moment-rotation relationships of blind bolted CFDST column composite connections.

• 대한물리의학회지
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• 제13권1호
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• pp.49-62
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• 2018

PURPOSE: This study investigated the influence of a specific hip joint exercise program on the characteristics of chronic low back pain (LBP), hip joint range of motion (ROM), and performance level in amateur golfers with LBP. METHODS: The study included 28 adult male amateur golfers with LBP and reduced internal rotation (IR) of the lead side hip joint. Subjects were randomly assigned to an experimental (EG) (n=14) or control group (CG) (n=14). The Numerical Rating Scale score for pain, ROM of the hip joint and trunk rotation, performance parameters for golfing were evaluated. A specific exercise program designed to improve IR of the lead side hip joint was performed by the EG, but not the CG. Post-intervention evaluation was performed and the collected data were analyzed. RESULTS: After the intervention, the severity of LBP was significantly reduced (p<.05) and the IR ROM of the lead side hip joint was significantly increased (p<.01) in the EG. Moreover, the trunk rotation range was significantly increased in the EG (p<.01). The drive distance was significantly difference between the EG and CG (p<.05). CONCLUSION: A specific hip joint exercise program can help to reduce pain level and improve performance level in amateur golfers with LBP and increased IR ROM of the lead side hip joint. A significant increase in ROM of the lead side hip joint reduce LBP and was related to driving distance in the EG.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.265-270
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• 2001

Hip joint simulator which Is an essential device for evaluating the wear of biomaterials (ultrahigh molecular weight polyethylene, Co-Cr alloy, alumina, etc.) used in total hip joint replacement was developed. This hip joint simulator mimics the joint motion and joint loading of human gait by adapting the 4 degree of freedom in kinematic motion (flexing/extension, adduction/abduction, Internal rotation/external rotation) and axial loading, Four stations are operated by 8 servo-motors and harmony drives. Joint leading was imposed by displacement control from a ball screw, LM guide, and spring system. Each kinematic link system operates separately or coupled modes. A heater and a thermocouple were installed for keeping the body temperature in each station.

• 융합정보논문지
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• 제10권5호
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• pp.188-197
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• 2020

본 연구는 관절가동술 후 두 가지 유형의 전기치료 방법을 각각 적용하였을 때 유방암 환자의 어깨 가쪽돌림 가동범위와 통증에 미치는 효과를 알아보기 위해 실시하였다. 유방절제술을 시행한 유방암 환자 30명을 STMG (관절가동술+비침습적 무통증 신호 전기치료) 15명과 TENMG (관절가동술+경피신경전기자극) 15명으로 나누었다. 중재는 4주간 주 3회, 1회당 1시간씩 실시하였다. 측정은 어깨 가쪽 돌림 관절가동범위(Range of motion, ROM), 통증(Visual analog scale)을 측정하였다. 중재 전·후 두 군 모두 어깨 가쪽돌림 관절가동범위, 통증에서 유의한 차이가 있었다(p<.05). STMG는 어깨 가쪽 돌림 관절가동범위를 제외하고 TENMG보다 통증 감소에서 더욱 효과적이었다(p<.05). 유방암 절제술 환자의 통증을 경감시키기 위해서는 STMG이 TENMG보다 더욱 효과가 있다는 것을 확인할 수 있었다. 다양한 차이를 확인하기 위해 대조군을 더하고, 더 많은 대상자가 필요할 것으로 사료된다.

• 로봇학회논문지
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• 제14권4호
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• pp.251-257
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• 2019

This paper presents the kinematic modeling of the human forearm rotation constructed with a spatial four-bar linkage. Especially, a circumduction of the distal ulna is modeled for a minimal displacement of the position of the hand during the forearm rotation from the supination to the pronation. To establish its model, four joint types of the four-bar linkage are, firstly, assigned with the reasonable grounds, and then the spatial linkage having the URUU (Universal-Revolute-Universal-Universal) joint type is proposed. Kinematic analysis is conducted to show the behavior of the distal radio-ulna as well as to evaluate the angular displacements of all the joints. From the simulation result, it is, finally, revealed that the URUU spatial linkage can be substituted for the URUR (Universal-Revolute-Universal-Revolute) spatial linkage by a kinematic constraint.

• Physical Therapy Rehabilitation Science
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• 제10권2호
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• pp.90-97
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• 2021

Objective: The purpose of this study was to find out how the back instability during clam exercise (CE) causes changes in pelvic rotation and hip joint abductor muscle activity, and to find out the effects with different methods of application of pressure biofeedback. Design: Comparative study using repeated measures. Methods: Each subjects performed the clam exercise (CE) without pressure biofeedback, the clam exercise with pressure biofeedback applied to the back (CE-PBU to back), and the clam exercise with pressure biofeedback applied to the side (CE-PBU to side). The amount of pelvic rotation was measured using myomotion. And the muscle activity of the muscle gluteus medius and the tensor fasciae latae was measured using EMG device. One-way repeated measures ANOVA followed by the Bonferroni post test were used to compare the EMG activity in each muscle and pelvic rotation angle during the CE, CE-PBU to back, CE-PBU to side. Results: The amounts of pelvic rotation was the lowest in CE-PBU to back (p< 0.05) and the ratio of muscle activity of the muscle gluteus / tensor fasciae latae was the highest in CE-PBU to back (p< 0.05). Conclusions: It is thought that, in order to stabilize the waist-pelvis and increase hip joint muscle strength in subjects with back instability, applying clam exercise with pressure biofeedback applied to the lower back is effective in improving waist-pelvic movements and selectively strengthening the muscle gluteus medius.

• Advances in nano research
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• 제14권2호
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• pp.117-126
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• 2023

This experimental study investigated friction stir welding (FSW) of the acrylonitrile-butadiene-styrene (ABS) T-joint in the presence of various nano-silica levels. This study aim to handle the drawbacks of the friction stir welding (FSW) of an ABS T-joint with various quantity of nanoparticles and assess the performance of nanoparticles in the welded joint. Moreover, the relationship between the nanoparticle quantity and FSW was analyzed using response surface methodology (RSM) Box-Behnken design. The input parameters were the tool rotation speed (400, 600, 800 rpm), the transverse speed (20, 30, 40 mm/min), and the nano-silica level (0.8, 1.6, 2.4 g). The tensile strength of the prepared specimens was determined by the universal testing machine. Silica nanoparticles were used to improve the mechanical properties (the tensile strength) of ABS and investigate the effect of various FSW parameters on the ABS T-joint. The results of Box-Behnken RSM revealed that sound joints with desired characteristics and efficiency are fabricated at tool rotation speed 755 rpm, transverse speed 20 mm/min, and nano-silica level 2.4 g. The scanning electron microscope (SEM) images revealed the crucial role of silica nanoparticles in reinforcing the ABS T-joint. The SEM images also indicated a decrease in the nanoparticle size by the tool rotation, leading to the filling and improvement of seams formed during FSW of the ABS T-joint.