• Korean Journal of Applied Biomechanics
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• v.29 no.4
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• pp.255-261
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• 2019

Objective: The purpose of this study was to investigate differences of shock attenuation strategies between double-leg and single-leg landing on sagittal plane using statistical parametric mapping. Method: Nine healthy female professional soccer players (age: 24.0±2.5 yrs, height: 164.9±3.3 cm, weight: 55.7±6.6 kg, career: 11.2±1.4 yrs) were participated in this study. The subjects performed 10 times of double-leg and single-leg landing from the box of 30 cm height onto force plates respectively. The ground reaction force, angle, moment, angular velocity, and power of the ankle, knee, and hip joint on sagittal plane was calculated from initial contact to maximum knee flexion during landing phase. Statistical parametric mapping was used to compare the biomechanical variables of double-leg and single-leg landing of the dominant leg throughout the landing phase. Each mean difference of variables was analyzed using a paired t-test and alpha level was set to 0.05. Results: For the biomechanical variables, significantly increased vertical ground reaction force, plantarflexion moment of the ankle joint, negative ankle joint power and extension moment of the hip joint were found in single-leg landing compared to double-leg landing (p<.05). In addition, the flexion angle and angular velocity of the knee and hip joint in double-leg landing were observed significantly greater than single-leg landing, respectively (p<.05). Conclusion: These findings suggested that negative joint power and plantarflexion moment of the ankle joint can contribute to shock absorption during single-leg landing and may be the factors for preventing the musculoskeletal injuries of the lower extremity by an external force.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.171-179
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• 2004

The purpose of this study is to generate cycling motion for FES (functional electrical stimulation) using knee muscles only. We investigated the possibility by simulation. The musculoskeletal model used in this simulation was simplified as 5-rigid links and 2 muscles (knee extensor and flexor). For the improvement of the present feedforward control in FES, we included feedback path in the control system. The control system was developed based on the biological neuronal system and was represented by three sub-systems. The first is a higher neuronal system that generates the motion command for each joint. The second is the lower neuronal system that divides the motion command to each muscle. And the third is a sensory feedback system corresponding to the somatic sensory system. Control system parameters were adjusted by a genetic algorithm (GA) based on the natural selection theory. GA searched the better parameters in terms of the cost function where the energy consumption, muscle force smoothness, and the cycling speed of each parameter set (individual) are evaluated. As a result, cycling was implemented using knee muscles only. The proposed control system based on the nervous system model worked well even with disturbances.

• The Journal of Korean Academic Society of Nursing Education
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• v.14 no.1
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• pp.20-29
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• 2008

Purpose: This research was conducted to compare the effects of a muscle strengthening exercise program on pain, straight leg raising ability, passive range of motion, independent walking time and satisfaction with total knee arthroplasty(TKA). Method: A nonequivalent control group posttest only design was used for this study. A total of 62 patients were randomly divided into the experimental group(31) and the control group (31). The experimental group received a 1-hour exercise intervention, while the control group received the usual care. Data was analyzed by t-test using the SPSS/WIN 11.0. Results: The experimental group showed significant improvement in pain score, straight leg raising ability, passive range of motion of knee joint, independent walking time, and the patient's satisfaction. Conclusion: The muscle strengthening exercise program was effective on decreasing pain and increasing mobility and satisfaction in patients with TKA.

• Applied Microscopy
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• v.45 no.3
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• pp.135-143
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• 2015

The aim of this study was to investigate effects on joint mobilization in neurochemical changes of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) and nitric oxide synthase (NOS) of the spinal cord neurons after right knee joint immobilization (RKJI) and in ultrastructural changes of the femoral nerves innervating the muscles acting on RKJI. A total of 15 guinea pigs were used and divided into 5 groups. Immunohistochemistry was performed to detect NADPH-d and NOS. NADPH-d and NOS were not expressed in the ventral horn of control and experimental groups, but were expressed or not in the dorsal horn according to the duration of release after RKJI and the presence or absence of joint mobilization. Ultrastructures of the femoral nerves in experimental groups had partial demyelination and condensed clumps in axon. Effects on manipulative therapy after RKJI were confirmed from expression of NADPH-d and NOS in the dorsal horn of the lumbosacral spinal cord. Manipulative therapy was more effective against a long-term immobilization than a short-term immobilization.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.8
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• pp.814-823
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• 2011

Nowadays many neurological diseases such as stroke and Parkinson diseases are continually increasing. Orthotic devices as well as exoskeletons have been widely developed for supporting movement assistance and therapy of patients. Robotic knee orthosis can compensate stiff-knee gait of the paralyzed limb and can provide patients consistent assistance at wearable environments. With keeping a robotic orthosis wearable, however, it is not easy to develop a compact and safe actuator with fast rotation and high torque for consistent supports of patients during walking. In this paper, we propose a novel kinematic model for a robotic knee orthosis to drive a knee joint with independent actuation during swing and stance phases, which can allow an actuator with fast rotation to control swing motions and an actuator with high torque to control stance motions, respectively. The suggested kinematic model is composed of a hamstring device with a slide-crank mechanism, a quadriceps device with five-bar/six-bar links, and a patella device for knee covering. The quadriceps device operates in five-bar links with 2-dof motions during swing phase and is changed to six-bar links during stance phase by the contact motion to the patella device. The hamstring device operates in a slider-crank mechanism for entire gait cycle. The kinematics and velocity/force relations are analyzed for the quadriceps and hamstring devices. Finally, the adequate actuators for the suggested kinematic model are designed based on normal gait requirements. The suggested kinematic model will allow a robotic knee orthosis to use compact and light actuators with full support during walking.

• Korean Journal of Applied Biomechanics
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• v.27 no.3
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• pp.165-169
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• 2017

Objective: The Star Excursion Balance Test (SEBT) and Y-Balance Test (YBT) have been commonly applied to measure dynamic postural stability ability. These two tests are utilized interchangeably in various settings. However, they could in fact require different movements to assess dynamic postural stability, as one uses a platform and different measuring techniques than the other. The purpose of this study was to determine if there was a significant difference in the kinematic patterns in physically active population while performing the SEBT and the YBT. Method: Seventy participants performed in the Anterior (AN), Posteromedial (PM), and Posterolateral (PL) directions of the SEBT and the YBT. The kinematics of hip, knee, and ankle in sagittal plane was calculated and analyzed. Paired-sample t-tests were performed to compare joint angular displacement in the ankle, knee, and hip between the SEBT and the YBT. Results: Significant differences in angular displacement at the hip, knee, and ankle joints in the sagittal plane between performance on the SEBT and on the YBT were observed. Conclusion: Clinicians and researchers should not apply these dynamic postural control tasks interchangeably from one task to another. There appear to be kinematic pattern differences between tests in healthy physical active population.

• Journal of muscle and joint health
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• v.18 no.2
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• pp.203-214
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• 2011

Purpose: The purpose of the study was to identify the effects for 4-weeks muscle strengthening exercise program on pain, fatigue, and physical function(muscle strength of leg, walking competence, balance, flexibility of patella) in elderly women with total knee arthroplasty(TKA). Method: Utilizing a quasi-experimental design, 30 TKA patients consisted of the experimental group (n=15) and control group (n=15). The experimental group participated in the muscle strengthening exercise program, twice a day for 4 weeks. Data were analyzed with SPSS WIN 18.0 program, using repeated measure ANOVA. Result: As time goes by, There were significant differences in muscle strength of leg (F=6.60, p<.001), walking competence(F=7.15, p<.001), and balance(F=17.55, p<.001) between the experimental and the control groups. Conclusion: The findings of this study revealed the positive effects of muscle strengthening exercise program in elderly women with TKA.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.1
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• pp.143-152
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• 2020

PURPOSE: This study examined the effects of videoconferencing-based telerehabilitation exercise program on the gait, knee function, and quality of life of patients with knee osteoarthritis. METHODS: Forty-eight subjects, who were diagnosed with osteoarthritis of the knee by the radiologic findings, history, and a physical examination, were assigned randomly to a Control group, Experiment group I, and Experiment group II. The control group did not perform any exercise program and were educated in understanding and managing the disease of knee osteoarthritis for only one hour. Experimental groups I and II were provided with an exercise guidelines book for knee osteoarthritis, and the same exercise programs were conducted by face-to-face visits and non-face-to-face using telerehabilitation for eight weeks, respectively. To verify the effectiveness of each exercise program, the gait speed, knee disability index, and health related quality of life were measured. All assessments were conducted twice before and after the intervention. RESULTS: The participants who underwent both face-to-face and telerehabilitation exercise programs showed an improved gait speed, knee function, and health-related quality of life. In particular, there was no significant difference between the telerehabilitation exercise group and the direct face-to-face exercise group in improving the knee joint function and health related quality of life. CONCLUSION: A these findings the telerehabilitation exercise program for patients with knee osteoarthritis can alternate or supplement the face-to-face exercise program. Therefore, the telerehabilitation exercise program should be used not only as a substitute supplement program but also as an intervention for various diseases.

• The Journal of Korean Physical Therapy
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• v.18 no.2
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• pp.35-45
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• 2006

Purpose: This study was to investigate the effect of isometric exercise and active stretching on joint function in patient with osteoarthritis. Methods: 30(M=1, F=29) subjects with osteoarthritis were divided in three groups: control group, quadriceps isometric exercise group, and hamstring active stretching group. After 6 weeks treatment, ROM(range of motion) and LSS(lysholm scoring scale) were measured. Results: There was a significant increase in knee flexion, extension in post-treat of quadriceps isometric exercise group and hamstring active stretching group(p<0.05). There was a significant increase in LSS in post-treat of quadriceps isometric exercise group and hamstring active stretching group(p<0.05). Conclusion: This study shows that both the active stretching exercise and the quadriceps isometric exercise effectively promote the range of knee extensions for osteoarthritis patients. Also, as measuring the ROM of knee flexion and extension by exercise methods, there is significant increase from knee flexion and extension in both hamstring stretching exercise group and quadriceps isometric exercise group. The increase of the range of knee is more effective in the exercise of knee extension with hamstring stretching exercise groups. And it is found that there are some difference between the experimental group and controlled group in statistics. As it is concerned with the function of knee extension, supporting and squatting are more effective to promote the both knee extension and flexion in its range. Therefore, this shows that the hamstring stretching exercise is required in general with enforcing the quadriceps at a sickbed in the present.

• The Journal of Dong Guk Oriental Medicine
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• v.9
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• pp.35-49
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• 2000

Purpose: This study is to investigate the alleviation effects of Daebangpoongtang in LPS induced arthritis in mice knee joint. Methods : Daebangpoongtang was chosen to treat the arthritis caused by injecting $300{\mu}g/kg$ LPS to mice knee joint. The control group had no treatment, while the LPS group was injected $300{\mu}g/kg$ LPS to mice knee joint and the DBP group was oral administrated of Daebangpoongtang. After injection of $300{\mu}g/kg$ LPS to mice knee joint, the alteration of synovial lining cell, vessel, fibrosis, distribution of collagen fiber, fibroblast, mast cell, infiltration of inflammation component cell and distribution of ICAM and VCAM was observed by light microscope(BX50). Results : In the DBP extract treatment group, the distribution of vessel, the enlargement of synovial lining cell layer, the synovial lining cells with filopodia, the fibrosis, the distribution of fibroblast in synovial membrane, the distribution of TCAM and VCAM on the knee joint was less than that of LPS group. Infiltrated lymphocyte into the apical surface had not observed in the DBP extract treatment group. The distribution of mast cell was as same as control group(no treatment group) and it showed granulated type. Conclusion: According to the above results, it might be considered that the administration of Daebangpoongtang has a curative effect on synovial membrane injury in arthritis by inhibiting increase of vessel, cell adhesion molecule(ICAM and VCAM) in LPS induced arthritis.