• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1210-1216
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• 2004

This paper deals with a human-like gait generation of a biped robot with a balancing weight of an inverted pendulum type by using genetic algorithm. The ZMP (Zero Moment Point) is the most important index in a biped robot's dynamic walking stability. To perform a stable walking of a biped robot, a balancing motion is required according to legs' trajectories and a desired ZMP trajectory. A dynamic equation of the balancing motion is nonlinear due to an inverted pendulum type's balancing weight. To solve the nonlinear equation by the FDM (Finite Difference Method), a linearized model of equation is proposed. And GA (Genetic Algorithm) is applied to optimize a human-like balancing motion of a biped robot. By genetic algorithm, the index of the balancing motion is efficiently optimized, and a dynamic walking stability is verified by the ZMP verification equation. These balancing motion are simulated and experimented with a real biped robot IWR-IV. This human-like gait generation will be applied to a humanoid robot, at future work.

• Journal of Korean Biological Nursing Science
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• v.20 no.3
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• pp.141-149
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• 2018

Purpose: This study was conducted to examine the effects walking program with dance on gait, cognition, and risk of falls of elderly with dementia in a long-term care hospital. Methods: Subjects consisted of 42 elderly with dementia in a long-term care hospital (21 elderly with dementia in an experimental group and 21 elders with dementia in a control group). Data were collected from March 14 to April 30, 2016. Subjects in the experimental group performed walking program with dance (three times a week, 30-50 minutes session, 18 sessions). Data were analyzed using descriptive statistics, Chi-square test, Fisher's exact test, independent t-test, paired t-test, repeated measures ANOVA with the SPSS/WIN 21.0. Results: The participants in the experimental group showed significantly increased scores of cadence (F= 8.36, p= .007) and improved scores of cognition (F= 9.95, p= .003) compared the control group. Conclusion: The findings indicate walking program with dance is recommend a regular exercise program to enhance the cadence associated with walking speed and cognitive function elderly.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.12
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• pp.1216-1222
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• 2009

This article describes a simple method for generating the walking trajectory for the biped humanoid robot. The method used a simple inverted model instead of complex multi-mass model and a reasonable explanation for the model simplification is included. The problem of gait trajectory generation is to find the solution from the desired ZMP trajectory to CoG trajectory. This article presents the analytic solution for the bipedal gait generation on the bases of ZMP trajectory. The presented ZMP trajectory has Fourier series form, which has finite or infinite summation of sine and cosine functions, and ZMP trajectory can be designed by calculating the coefficients. From the designed ZMP trajectory, this article focuses on how to find the CoG trajectory with analytical way from the simplified inverted pendulum model. Time segmentation based approach is adopted for generating the trajectories. The coefficients of the function should be designed to be continuous between the segments, and the solution is found by calculating the coefficients with this connectivity conditions. This article also has the proof and the condition of solution existence.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.10
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• pp.56-64
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• 2009

This paper presents a parallel typed walking robot which can walk in omni-direction and climb from a floor to a wall. We design a six D.O.F leg mechanism composed of three legs, which form a parallel mechanism with a base and a ground to generate arbitrary poses. Optimal design is conducted to maximize the walking space and the dexterity, which are normalized by the stroke of leg. Kinematic parameters are found to maximize the weighted optimal objectives. We design a triple parallel mechanism robot by inserting Stewart platform between the upper leg mechanism and the lower leg mechanism and examine the gaits when the robot walks on the ground and climbs from a floor to a wall. The analysis of walking space and dexterity for each gait shows that the triple parallel walking robot has a large walking space with a large stability region. We explore the possibility that the robot can climb from a floor to a wall. Investigating the gaits for the six steps proves that the robot can lift the foot up to the wall by combining the orientational walking space generated by three parallel mechanisms.

• The Journal of Korean Physical Therapy
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• v.33 no.1
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• pp.34-39
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• 2021

Purpose: The purpose of this study was to verify the effectiveness of repetitive sit to stand training to improve knee extensor strength and walking ability of total knee replacement patients. Methods: In this study, 12 patients with total knee replacement patients were recruited from a rehabilitation hospital. They were divided into two groups: a repetitive sit to stand group (n=6) and a control group (n=6). They all received 30 minutes of continuous passive motion (CPM). After that, the repetitive sit to stand group performed repetitive sit to stand training, and the control group performed resistance exercise for 15 minutes five times a week for 2 weeks. After 2 weeks of training, knee extensor strength and spatiotemporal gait parameters were measured. Knee extensor strength was measured by Biodex system 3, walking ability was measured by Biodex gait trainer 2. Paired t test was performed to verify the difference between before and after intervention within the group, and analysis of covariance was used to verify the differences between the two groups. Results: After the training periods, the repetitive sit to stand group showed a significant improvement in knee extensor muscle strength, walking speed, step length of the operated side, and step length of the non-operated side (p<0.05). Conclusion: The results of this study showed that repetitive sit to stand training was more effective in improving knee extensor muscle strength and walking ability. Therefore, to strengthen knee extensor muscles and improve the walking ability of total knee replacement patients, it is necessary to consider repetitive sit to stand training.

• PNF and Movement
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• v.10 no.4
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• pp.1-7
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• 2012

Purpose : The purpose of this study was to evaluate the relationship between physical performance, such as gait and postural control, and cognition on as assessed by clinical tools in individuals with chronic hemiparetic stroke. Methods : Twenty-six patients who had hemiparetic stroke participated in this study, and were evaluated four common clinical measurements, including the Berg balance scale (BBS), 10 meter walk test (10MWT), 6 minute walking test (6MWT), and Montreal cognitive assessment (MoCA). Multiple regression analysis was used BBS score, 10MWT, and 6MWT as the dependent variables; MoCA score, post-stroke duration, age, and affected side as independent variables. Results : In the regression equation of the BBS score, the correlation coefficient (r) was 0.875, the coefficient of determination (R2) was 0.786, and the MoCA score was the most important variable for determining the BBS score. In the regression equation for the 10MWT, ther was 0.888, the R2 was 0.999, and the MoCA score was the most important variable for determining 10MWT. Finally, the r was 0.777, the R2 was 0.998, and the MoCA score was the most important variable for determining 6MWT in the regression equation of the 6MWT. Conclusion : The results show that cognitive abilities affect gait proficiencies in individuals with chronic hemiparetic stroke. Therefore, these results suggest that cognitive tests are necessary for examining and evaluating the abilities of postural control and gait performance for chronic stroke patients in research and clinical environments.

• The Journal of Korean Physical Therapy
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• v.36 no.1
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• pp.27-32
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• 2024

Purpose: This study was conducted to verify the effect of applying a pressure biofeedback unit on walking ability and knee joint function while performing knee joint extensor strengthening exercises using resistance exercise equipment in total knee replacement (TKR) patients. Methods: This study was conducted on twelve patients receiving rehabilitation treatment after being admitted to a rehabilitation hospital post-TKR. Of these, six were allocated to a feedback group with a pressure biofeedback unit, and the other 6 were allocated to a control group without a pressure biofeedback unit. The subjects performed an exercise program for 45 minutes per session, five times a week, for two weeks. Walking ability and knee joint function were evaluated and analyzed before and after exercise. Results: The feedback group showed significantly better improvements in walking speed, gait cycle, step length on the non-operation side, time on the foot on the operation side, K-WOMAC stiffness, and K-WOMAC function than the control group (p<0.05). Conclusion: When strengthening the knee joint extensor muscles using resistance exercise equipment in TKR patients, the provision of a pressure biofeedback unit was found to improve walking ability and knee joint function by inducing concentric-eccentric contraction of the knee joint extensor muscles. Therefore, the study shows that exercise based on the provision of a pressure biofeedback unit should be considered when strengthening knee joint extensor muscles to improve the walking ability and knee joint function of TKR patients in clinical practice.

• ETRI Journal
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• v.35 no.6
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• pp.1029-1037
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• 2013

This paper introduces a novel and fast synthesizing method for 3D motions of quadrupedal animals that uses only a small set of motion capture data. Unlike human motions, animal motions are relatively difficult to capture. Also, it is a challenge to synthesize continuously changing animal motions in real time because animals have various gait types according to their speed. The algorithm proposed herein, however, is able to synthesize continuously varying motions with proper limb configuration by using only one single cyclic animal motion per gait type based on the biologically driven Froude number. During the synthesis process, each gait type is automatically determined by its speed parameter, and the transition motions, which have not been entered as input, are synthesized accordingly by the optimized asynchronous motion blending technique. At the start time, given the user's control input, the motion path and spinal joints for turning are adjusted first and then the motion is stitched at any speed with proper transition motions to synthesize a long stream of motions.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.959-964
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• 1992

This study treats the method for kinematic modeling of the biped walking robot, for synthesizing various gait trajectories, and for calculating adequate values of the joint torque inside the stable region. To synthesize various and anthropomorphic walking easily, the gait trajectory is specified by a set of ten walking prameters, and the trunk motion equation is derived by the zero moment point and the gait trajectory. By distributing ground reaction force and moment reduced at the zero moment point to the both feet, the joint torque equation can be derived readily, and according to this equation, the joint torque to stable walking can be computed.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.4
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• pp.33-39
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• 2016

Purpose : The aim of this study was to investigate the effects of plastic ankle foot orthosis on adult post-stroke hemiplegic patients walking ability and balance. Method : The searched for the case controlled clinical trials about the effects of plastic ankle foot orthosis(pAFO) for walking ability and balance using quantitative gait analysis in adult post-stroke patients. Ten trials were selected from Riss4U databases published until June 2016 in Korea. The selected trials contained a control group with pre-test and post-test design, measured walking ability and balance as a dependent variable. Result : The selected ten trials involved a total of 180 patients. The walking speed, cadence, the portion of double limb supporting, stride length on affected side were improved by plastic ankle foot orthosis. Conclusion : The plastic ankle foot orthosis has some evidence to improve the walking ability and balance in post-stroke hemiplegic patients.