• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.95-104
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• 2008

The purpose of this study was to investigate kinematic coordination and control of lower segments in skill process. For the investigation, we examined the difference of resultant linear velocity of segments and angle vs angle graph. Novice subjects were 9 male middle school students who has never been experienced a taekwondo and expert subjects were 7 university taekwondo players. We analyzed kinematic variables of Dollyochagi motion through videographical analysis and the conclusion were as follows. 1. Examining the graph of novice subjects' maximal resultant linear velocity of the thigh, shank, and foot segment, as it gets closer to the end of the training, the maximal resultant linear velocity in each segment increased. Statistical analysis showed the following results; thigh segment caused the increase of speed, using the trunk segment's momentum in the latter term of learning, while the shank segment utilized the momentum of the adjacent proximal segment at the beginning of learning, and the foot segment in the middle of learning. 2. Until the point where the knee joint angle is minimum, as the novice group learn the skill, the flexion of knee and hip joints has changed into the form of coordination pattern in phase. On the other hand, the expert group showed continual coordination pattern in phase that the movement sequences were smooth. From the knee joint maximal flexion to impact timing, all novice and expert groups showed coordination pattern out of phase. 3. From the knee joint maximal flexion to impact timing, the ankle joint was fixed and the knee joint was extended to all the novice stages and expert subjects.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.43-43
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• 2000

In this paper, we introduce a case study of developing a miniature humanoid robot that has 16 degrees of freedom and is able to perform statically stable walking. The developed humanoid robot is 37cm tall and weighs 1,200g. RC servo motors are used as actuators. The robot can walk forward and turn to any direction on even surface. It equipped with a small digital camera, so it can transmit vision data to a remote host computer via wireless modem. The robot can be operated in two modes; One is a remote-controlled mode, in which the robot behaves according to the command given by a human operator through the user-interface program running on a remote host computer, the other is a stand-alone mode, in which the robot behaves autonomously according to the pre-programmed strategy. The user-interface program also contains a robot graphic simulator that is used to produce and verify the robot's gait motion. In our walking algorithm, the ankle joint is mainly used lot balancing the robot. The experimental results shows that the developed robot can perform statically stable walking on even surface.

• Journal of muscle and joint health
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• v.2 no.2
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• pp.131-146
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• 1995

Many arthritis patients experience weakness of muscles in extremities mainly due to disuse atrophy and weight gain because of the limited activities and exercises. This study examines the effects of the 6-week aquatic-exercise program on the body fat and the muscle of the rheumatoid arthritis patients. Seventeen patients in the experimental group and 18 in the control group were assigned depending on their preference and physical condition. These patients had more than 3 points of pain out of 10, deformities in knee, wrist and ankle joints. The amount of aquatic exercise increases from 35 minutes in the first week to 60 minutes in the 6th week. In the resting period they discussed their own experiences about exercise, personal and family affairs, and performed some recreation programs in order to increase the self-efficacy and promote the relationship with other patients by the group activities. Skinfold thickness and circumferences of both extremities were measured before and after experiment to compare the difference. For testing the body fat Saham Model was used. Prior to the experiment two group's body weight, skinfold thickness and skin circumferences were not significantly different which indicates the homogeneity of two groups. Body weight and most parts of skinfold thickness of the experimental group were significantly lower than the control group after 6-week aquatic exercise program. Circumference was not significantly lower than the control after the program. These findings indicate the in-crease of muscle sizes and the reduction of the body fat. Therefore a more active application of aquatic exercise into a variety of clients is strongly suggested.

• Journal of Korean Physical Therapy Science
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• v.4 no.1
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• pp.229-242
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• 1997

This study was performed to figure out effects of stroke rehabilitation on education using isokinetic exercise on physical function recovery. It is considered isokinetic exercise will playa primary role in muscle strength, ROM of joint, and body balance recovery for stroke rehabilitation and so far can be used as a basic references to increase the health of all people. The study consisted of 42 stroke patient(21 training group, 21 control group) diagnosed as cerebral hemorrhage from Oriental Rehabilitation Department of Kyung Hee University. Upper extremity and lower extremity exercise was performed in the training group using isokinetic ergometer. The recovery of physical function(muscle strength, ROM of joint, body balance) data between the two groups were compared and ana lysed by paired t-test are as followed. 1. Muscle testing record showed increased in the strength of elbow flexion, knee flexion, knee extension, ankle extension of the training group com paired to control group(p < .05). In the measurement of ROM, however other parts of the body motion showed no significant changes, only shoulder extension of the training group was increased(p < .05). 2. Body balance increase was highly significant in all training group compaired to control group(p<001). Based on these findings, stroke rehabilitation education with isokinetic ergometer showed available effects on recovery of physical function rehabilitation program with isokinetic exercise will play a primary role in the recovery of physical function of stroke or brain injury patients as well as to promote the health of all people.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.1
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• pp.35-40
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• 2011

Purpose: This study was performed to evaluate the diagnostic usefulness of ankle stress radiograph for evaluation of chronic lateral ankle instability. Materials and Methods: Among patients undergoing the modified-Brostrom procedure, 42 cases with complete rupture of the anterior talofibular ligament were enrolled in this study. Sixty Korean adults (120 cases) were recruited as the control group. Radiologic measurement of talar tilt and anterior talar translation was performed through stress radiographs using Telos device. We obtained the normal range of Korean adults, and used as a standard value for judgment of mechanical instability. We analyzed the sensitivity, specificity, positive and negative prediction value of ankle stress radiograph. Results: On ankle stress radiograph, normal range of talar tilt angle and anterior talar translation was below $8.3^{\circ}$, below 7.6mm. Talar tilt angle on varus stress radiograph showed 57% of sensitivity, 97% of specificity, 89% of positive and 86% of negative prediction value. Anterior talar translation on anterior drawer stress radiograph showed 69% of sensitivity, 97% of specificity, 91% of positive and 90% of negative prediction value. Conclusion: Ankle stress radiograph had a good specificity, positive and negative prediction value for the evaluation of mechanical instability. However it underestimated the mechanical instability of ankle joint. It must be remembered that normal stress radiograph does not exclude ankle instability.

• Journal of Acupuncture Research
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• v.26 no.6
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• pp.51-65
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• 2009

Objectives : This study was built to investigate the effect of Trachelospermi Caulis herbal-acupuncture on the Collagen-induced arthritis(CIA) in rats. Methods : Arthritis was induced by intradermal injection of Bovine type II collagen solution into base of tail. Experimental group were divided into 5 groups ; Normal(N) group, Control(C) group, Trachelospermi Caulis high(TH) group, Trachelospermi Caulis low(TL) group, Saline(S) group(n=7 for each group). Normal group was had no management. Control group was injected with Bovine type II collagen solution and taken no treatment. Trachelospermi Caulis high group was injected with Bovine type II collagen solution and taken high-intensity(10mg/kg) herbal-acupuncture treatment on $ST_{36}$. Trachelospermi Caulis low group was injected with Bovine type II collagen solution and taken low-intensity(5mg/kg) herbal-acupuncture treatment on $ST_{36}$. Saline group was injected with Bovine type II collagen solution and taken saline injection on $ST_{36}$. Body weight, paw edema volume and ankle joint thickness were measured during experimental day. On the last experimental day, we analyzed WBC count, TNF-$\alpha$ & IL-$1{\beta}$ concentration, c-fos immunohistochemistry and NADPH-d histochemistry for evaluating the effect of Trachelospermi Caulis herbal-acupuncture. Results : The results were as follows ; 1. In the change of paw edema volume, TH group only has significant difference compared with C group. 2. In the change of ankle joint thickness, TH group only has significant difference compared with C group. 3. In WBC count of serum, TH, TL groups have significant decrease compared with C group. 4. In TNF-$\alpha$ concentration of effusion, TH, TL groups have significant decrease compared with C group. and TH group has significant decrease compared with TL group. 5. In IL-$1{\beta}$ concentration of effusion, TH, TL groups have significant decrease compared with C group. and TH group has significant decrease compared with TL group. 6. In c-fos positive neurons of S1S2(cortex) region, TH, TL, S groups have significant decrease compared with C group. 7. In NADPH-d positive neurons of CPu(caudate putamen) region, TH, TL groups have significant decrease compared with C group. 8. In NADPH-d positive neurons of Tfp(transverse fibers of pons) region, TH, TL, S groups have significant decrease compared with C group. and TH group has significant decrease compared with S group. Conclusions : According to above results, we hope that Trachelospermi Caulis herbal-acupuncture may have the effect that decreases progression and development of CIA. And it can be suggested that Trachelospermi Caulis herbal-acupuncture may reduce the expression of c-fos and NOS.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.1
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• pp.79-90
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• 2010

Objectives : Tai Chi for arthritis was developed in 1997 by Paul Lam, M.D. of family medicine in Australia. It is an exercise treatment program and a good approaching method for arthritis. However its application is limited to arthritis of knee joint only. Even there have been no clinical study in korean traditional medical society. The aim of this study is to investigate effect of the Tai Chi for arthritis on chronic pain of body. Methods : We designed this trial as objectives were (1) senior female over 60 years, (2) suffering for osteoarthritis and chronic body pain, (3) have no physical or mental dysfunctions (4) able to walk and exercise alone. Objectives mactched these criteria had been trained the Tai Chi for arthritis 2 hours a day for 21 weeks. Before and after training, pain of 8 joints (neck, shoulder, elbow, wrist, waist, hip, knee, ankle) were estimated with the VAS(Visual Analog Scale). Results : Training the Tai Chi for arthritis relieved multiple joint pain(especially neck, lower back, shoulder, wrist and knee) and these were statistically significant. Conclusions : This study is a pilot study to investigate effect of the Tai Chi for arthritis on chronic pain of whole body. Absence of control group, and other scale to test joint function except VAS were limitations of this study. It is the first clinical approach about Tai Chi in korean medicine field, also the first study of Tai Chi for pain of the whole body.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.99-116
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• 2003

The purpose of this study was to kinematics factors on during round-off at end of beam-salto backward stretched with step-out to cross on balance beam. Four elite female gymnastics players participated as subject of this study. The methods of this study was analyzed using three dimentional analysis. The results and conclusion of this paper is obtained as follows ; 1. The phase of time was the most short time in board touch down phase and board take-off phase. Also, it was shown a more long time in total time compared to previous study. 2. The horizontal displacement of each phase was shown the most high levels in balance beam landing. The vertical displacement was display a non-linearity increase in board take-of phase, and it was shown the most high levels in vertical displacement during landing of balance beam. 3. The horizontal velocity of each phase was shown the most high levels in board touch down, and it was display a gradually decreased levels because flight during board take-of. The resultant velocity of CG on each phase was shown the most high levels in board touch down and board take-off. 4. The angle of hip joint was shown the most high levels as performed a motion in extension state during board take-off, and the angle of knee joint was display a increased levels because of flight cause body extension in board take-off. Also the angle of ankle joint was shown a increasing levels during board take-off. Considering to this results, it is suggest that the change of kinematics factors in board touch down and board take-off is key role on the effective board control.

• Journal of Biosystems Engineering
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• v.32 no.5
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• pp.339-347
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• 2007

A hexapod walking robot had been developed for gathering information in the field. The developed robot was $260{\times}260{\times}130$ ($W{\times}L{\times}H$, mm) in size and 14.7 N in weight. The legs had nineteen degrees of freedom. A leg has three rotational joints actuated by small servomotors. Two servomotors placed at ankle and knee played the roles of vertical joint for up and down motions of the leg and the other one placed at coxa played the role of horizontal joint for forward and backward motions. In addition, a servomotor placed at thorax between the front legs and the middle legs played the role of vertical joint for pumping the two front legs to climb stair or inclination. Walking motion of the robot was executed by tripod gait. The robot was controlled by manual remote-controller communicated by an infrared ray. Two controllers were equipped to control the walking of the robot. The sub-controller using PIC microcomputer (Microchips, PIC16F84A) received the 16 bit command signal from the manual remote controller, decoded it to 8bit and transmitted it to the main microcomputer (RENESAS, SH2/7045), which controlled the 19 servomotors using the PWM command signals. Walking speeds were controlled by adjusting the period of command cycle and the stride. Forward walking speed were within 100 cm/min to 300 cm/min. However, experimental walking speed had the error of 4-40 cm/min to compare with the theoretical one, because of slippage of the leg and the circular arc motion of servomotor of coxa.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.103-110
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• 2009

The purpose of this study is to suggest a proper tread of stairs using kinematic factors and moments of the lower-limb joints in the stair decent with the 3 different treads with boimechanical method in ergonomics. 9 subjects (body masses; $59.41{\pm}7.49$, $64.03{\pm}6.65$, $67.26:{\pm}7.58$, heights; $160.50{\pm}6.35$ ages; $31.22{\pm}2.99$; parity; $1.67{\pm}0.71$) participated in three experiments that were divided by physiological symptoms (the early (0-15 weeks), middle (16-27 weeks) and last (18-39 weeks). and they walked at self-selected pace on 4 staircases 3 trials. As extending the pregnancy period, cadence was shorter but cycle time were longer more and more. As extending treads of stair decent during pregnancy, speed, stride lengths and cycle time were increased. As extending the treads of stair decent, hip and ankle moments increased but knee moments decreased in sagittal plane. There were increasing or decreasing of moments by means of treads. These changes may account for relation between the treads of stair and moments in pregnant women. The main changes of pregnant women were joint moments and kinematic factors during pregnancy period because pregnancy makes them physical changes. It is possible that joints have connection with compensation each other to maximize stability and to control gait motion. In conclusion, we suggest that the tread of stair is longer than 26cm tread. and exercise programs to improve muscle activity were necessary where joint moments were small.