• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.98-100
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• 1997

This paper proposes a mathematical model of impact force generated by collision between landing foot and ground, by which a dynamic analysis and a supplementation of existing stability criteria are made. By using the proposed dynamic analysis, an energy-optimized gaital algorithm is proposed. To prove the effectiveness of the algorithm, simulation results are shown compared to the result of previous gaital algorithm.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.882-887
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• 2008

In this paper, the dependency of energy efficiency on the walking/running pattern and the walking/running period is analyzed though simulations of walk, trot and gallop. A quadruped animal has its own original features in the walking pattern and the walking period for adaptation to the environment. The robot model used in the simulations has three active joints and one passive spring-loaded joint at each leg, which is based on the actual quadruped robot, HUNTER (Hanyang UNiversity TEtrapod Robot), developed in the lab. Also included is the dependency of energy efficiency on the walking period in trot.

• The Journal of Korean Physical Therapy
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• v.34 no.6
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• pp.292-297
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• 2022

Purpose: This study describes the effects of kicking a ball training on balance and upper limb function in chronic hemiplegia. Methods: Thirty chronic stroke patients were randomly selected; Kicking a ball (n=10), Treadmill gait (n=10), Stepping on the ground group (n=10). The Short Physical Performance Battery (SPPB) for balance and Foot Scan for weight distribution. Upper limb function was measured by the Manal Function Test (MFT). This treatment was performed five times a week for a total of 4 weeks. Results: Kicking group was significantly increased in SPPB (p<0.05) and MFT (p<0.05) between pretest vs post test and pretest vs follow-up. Conclusion: Kicking a ball was effective for improving weight acceptance on the paretic leg, balance and upper limb function. However, In terms of balance, the core stabilization that affected the upper extremity function was not evaluated. Thus, additional research may help determine correlation between core stability and upper limb function to improve balance.

• Journal of Biomedical Engineering Research
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• v.34 no.2
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• pp.80-90
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• 2013

Recently, functional insoles of wedge-type it is for the young to raise their height inserted between insole and heel cause foot pain and disease. Additionally, these have a problem with stability and excessively load-bearing during gait like high-heel shoes. In this study, we compared the changes in biomechanical characteristics of foot with different insole thickness then we will utilize for the development of the insole with the purpose of relieving the pain and disease. Subjects(male, n = 6) measured COP(center of pressure) and PCP(peak contact pressure) on the treadmill(140cm/s) using F-scan system and different insole thickness(0~50 mm) between sole and plantar surface during gait. Also, we computed changes of stresses at the foot using finite element model with various insole thickness during toe-off phase. COP moved anterior and medial direction and, PCP was increased at medial forefoot surface, $1^{st}$ and $2^{nd}$ metatarsophalangeal, ($9%{\uparrow}$) with thicker insoles and it was show sensitive increment as the insole thickness was increased from 40 mm to 50 mm. Change of the stress at the soft-tissue of plantar surface, $1^{st}$ metatarsal head represents rapid growth($36%{\uparrow}$). Also, lateral moments were increased over the 100% near the $1^{st}$ metatarsal as the insole thickness was increased from 0 mm to 30 mm. And it is show sensitive increment as the insole thickness changed 10 mm to 20 mm. As a result, it was expected that use of excessively thick insoles might cause unwanted foot pain at the forefoot region. Therefore, insole thickness under 30 mm was selected.

• Physical Therapy Korea
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• v.24 no.2
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• pp.58-65
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• 2017

Background: Children with cerebral palsy (CP) have impaired postural control, but critically require the control of stability. Consequently, therapeutic interventions for enhancing postural control in children with CP have undergone extensive research. One intervention is sensorimotor training (SMT) using a Flexi-bar, but this has not previously been studied with respect to targeting trunk control in children with CP. Objects: This study was conducted to determine the effect of SMT using a Flexi-bar on postural balance and gait performance in children with CP. Methods: Three children with ambulatory spastic diplegia (SD) participated in the SMT program by using a Flexi-bar for forty minutes per day, three times a week, for six weeks. Outcome variables included the pediatric balance scale (PBS), trunk control movement scale (TCMS), 10 meter walking test (10MWT), and 3-dimensional movement coordination measurement. Results: The SMT provided no statistically significant improvement in PBS, TCMS, 10MWT, or 3-dimensional movement coordination measurement. However, positive changes were observed in individual outcomes, as balance and trunk control movement were improved. Conclusion: SMT using a Flexi-bar may be considered by clinicians as a potential intervention for increasing postural balance and performance in children with SD. Future studies are necessary to confirm the efficacy of Flexi-bar exercise in improving the functional activity of subjects with SD.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.2
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• pp.105-113
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• 2022

Purpose: The purpose of this study is to investigate the effect of non-invasive transcranial direct current stimulation (tDCS) on muscle activity, including 10 m WT, TUG, and BBS, in hemiplegic stroke patients. Methods: This study was conducted on 42 inpatients diagnosed with hemiplegia due to stroke at hospital B in Daejeon for more than 6 months. Walking training was conducted for six weeks, five times a week for 30 minutes, with a general walking group (14 people), tDCS walking group (14 people), and tDCS (sham) walking group (14 people). Results: As a result of the study, the change in the muscle activity before and after tDCS intervention was significantly increased in the tibialis anterior muscle in the CG group. In the EG group, the erector spine (lumbar), rectus femoris, and tibialis anterior muscles significantly increased. In the SEG group, significant increases were observed in the rectus femoris and tibialis anterior muscles. Significant differences were found in the rectus femoris and tibialis anterior muscles in the comparison between groups after intervention according to tDCS application. Also, 10 m WT, TUG, and BBS were significantly increased in the CG, EG, and SEG groups after intervention, and there were significant differences in 10 m WT, TUG, and BBS in comparison between groups after intervention according to tDCS application. Conclusion: As a result, tDCS is an effective in improving the walking ability of stroke patients, and in particular, it effectively increases the muscle activity of the rectus femoris and tibialis anterior muscles, which act directly on walking, and also improves the speed and stability of walking. It is considered being an effective method to increase the gait of stroke patients by combining it with the existing gait training.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.51-59
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• 2011

This paper is concerned with locomotion of dog-like quadruped robots that can adapt to various terrains, mainly dealing with implementation methods and characteristics of static and dynamic gaits. To this end, a 12-DOF robot is built in house, motional trajectories of its body and feet are generated mimicking biological life, and the corresponding leg joint angles are analytically obtained by inverse kinematics. Such joint angle data are then applied to the robot's ADAMS model for computer simulations so that the planned walk and trot gaits are both confirmed dynamically stable. However, contrary to the simulation results, previous trot patterns showed unstable behavior during experiments. This problem led us to analyze the reason, and in the course we discovered the importance of maximally utilizing the concept of WSM rather than ZMP and therefore reducing the gait period to secure the stability of dynamic gaits such as trot.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.27-34
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• 2022

In this study, we aimed to determine which medical conditions of the stroke patients admitted for rehabilitation more than four weeks after onset affect caregiver burden. Participants diagnosed with stroke and their respective primary caregivers were enrolled and assessed after an 8-week follow-up period. The areas of evaluation for stroke patients included neurologic state, cognition, performance in daily life movements, gait, and balance, and caregivers were evaluated in the area of burden. The evaluation was conducted at the start of the rehabilitation course and eight weeks later. Patient caregivers were found to be under mild to moderate burden while providing care throughout the hospitalization period. The patient's neurologic state and cognition were correlated with caregiver burden. In the all patient and the subacute stroke patient group, multiple regression analysis confirmed that the neurologic state and balance stability were factors that influenced caregiver burden. Hence, we suggest that improvement in the patient's balance stability be emphasized during the course of rehabilitation to mitigate caregiver burden.

• Physical Therapy Korea
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• v.20 no.1
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• pp.18-27
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• 2013

The purpose of this study was to compare the ring lock type knee-ankle-foot orthosis (KAFO) with newly developed 4-bar linkage KAFO on the gait characteristics of persons with poliomyelitis clinically. This 4-bar linkage is the stance control type KAFO which provide the stability during stance phase and knee flexion during swing phase. Two subjects participated in this study voluntarily. We provided the customized 4-bar linkage KAFO then asked the subjects to walk in level surface and stairs under the two different KAFO conditions. The characteristics of gait in the persons with poliomyelitis were evaluated using a 3D motion analysis system and force plate. Additionally 6 minute walk test for physiological cost index were conducted using pulse oximeter to measure the energy consumption. In the results of this study, the differences of 4-bar linkage KAFO compared with ring lock type KAFO are as follows: (1) Walking speed, stride length, and step length on level increased in subjects, (2) The gait symmetry was improved by generated knee flexion and decreased pelvic external rotation on level and stairs walking, (3) Decreased vertical excursion of center of mass and pelvic elevation during swing phase was decreased on level, (4) Knee extension moment, hip flexion moment, hip and knee internal rotation moment of non-braced limb were decreased on level walking, (5) Walking speed in 6-minute walk test was increased and physiological cost index was decreased. These findings indicate that 4-bar linkage KAFO compared with ring lock type KAFO is effective in enhancing pattern, endurance, and energy consumption in level surface and stairs walking.

• Physical Therapy Korea
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• v.25 no.3
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• pp.19-26
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• 2018

Background: Genu varum is also known as bow leg. It is a deformity wherein there is lateral bowing of the legs at the knee. it does give rise to pain, and persistent bowing can often give rise to discomfort in knees, hips and ankles. Objects: This study investigated the effect of narrow squats on the knee joint during a gait and distance between the knees of person with genu varum. Methods: This study analyzed 23 patient with genu varum that grade III, 12 narrow squat group and 11 genenal squat group in motion analysis laboratory. The subjects of experiment took gait before and after intervention, the range of joint motion, moment of knee joint adduction, power, distance of the knees were measured. And in order to make an analysis between groups, an paiered t-test and independent t-test was carried out. For statistical significance testing, it was decided that significance level ${\alpha}$ be .05. Results: It was shown that the group of narrow squat exercise significantly decreased in distance of knees (p<.05),In moment of adduction of knee joint, it was shown to significantly decrease in two groups (p<.05), was significantly decreased in adduction, abduction, and rotation (p<.05). In relation of peak-knee adduction moment and valgus angle, there was significant decrease in narrow squat group (p<.05). Conclusion: When the above result of study were examined, a narrow squat exercise given to the genu varum patients significantly decreased the distance between the knees, range of knee adduction and abduction, knee adduction moment, knee power. And stability gains through the decrease of excursion of knee medial part be effective for the correction of genu varum deformation.