• Journal of Institute of Control, Robotics and Systems
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• v.11 no.1
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• pp.58-66
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• 2005

Usual human gait can be modeled as continual impact phenomenon that happens due to the topological change of the kinematic structure of the two feet. The human being adapts his own control algorithm to minimize the ill effect due to the collision with the environment. In order to operate a Humanoid robot like the human being, it is necessary to understand the physics of the impact and to derive an analytical model of the impact. In this paper, specially, we focus on impact analysis of the kicking motion in playing soccer. At the instant of impact, the external impulse exerted on the ball by the foot is an important property. Initially, we introduce the complete external impulse model of the lower-extremity of the human body and analyze the external impulses for several kicking postures of the lower-extremity. Secondly, a trajectory-planning algorithm of a ball, in which the initial velocity and the launch angle of the ball are calculated for a desired trajectory of the ball, will be introduced. The aerodynamic effect such as drag force and lift force is also considered. We carry out numerical simulation and experimentation to verify the effectiveness of the proposed analytical methodology.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.4
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• pp.9-14
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• 2013

Purpose : The purpose of this study was to investigate the effect of visual Auditory rhythmic stimulation(VARS) in gait ability and proprioception with chronic stroke patients. Twenty-one persons after six months post stroke participated in pre test-post test control. Method : The subjects were randomly assigned to a visual Auditory rhythmic stimulation(VARS) group (n=10) and control group (n=11). Training process was practiced with exercise on thirty minutes a day, three days a week for four weeks. To find out the effect, inspected the FRT(functional reach test) by static balance and TUG(timed up and go test) by dynamic balance. Results : In static balance, FRT distance was significantly different between two group. In dynamic balance, TUG time was significantly different between two group. This study showed that the VARS training increase a balance by postural adjustment of chronic stroke patients more than control group. And so, the VARS training of hemiplegic patients was very important to successive rehabilitation. Conclusion : A continuous examination of VARS training could practical used of physical therapy with exercise.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.223-228
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• 2011

In this paper, we proposed a technique to recognize three states in stance phase of gait cycle. Walking assistive devices are used to help the elderly people walk or to monitor walking behavior of the disabled persons. For the effective assistance, they adopt an intelligent sensor system to understand user's current state in walking. There are three states in stance phase; Loading Response, Midstance, and Terminal Stance. We developed a foot pressure sensor using 24 FSRs (Force Sensing/Sensitive Resistors). The foot pressure patterns were integrated through the interpolation of FSR cell array. The pressure patterns were processed to get the trajectories of COM (Center of Mass). Using the trajectories of COM of foot pressure, we can recognize the three states of stance phase. The experimental results show the effective recognition of stance phase and the possibility of usage on the walking assistive device for better control and/or foot pressure monitoring.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.132-137
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• 2011

The walking mobility with stability of 4 legged robots is the distinguished skills for many application areas. Planning gaits of efficient walking for quadruped robots is an important and challenging task. Especially, autonomous generation of locomotion is required to manage various robot models and environments. In this paper, we propose an adaptive locomotion control of 4 legged robot for irregular terrain using HyperNEAT. Generated locomotion is executed and analysed using ODE based Webots simulation for the 4 legged robot which is built by Bioloid.

• Physical Therapy Rehabilitation Science
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• v.7 no.1
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• pp.6-12
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• 2018

Objective: The purpose of this study was to investigate the effects of an additional weight aquatic exercise program on the balance and lower extremity strength on aquatic environment in persons with stroke. Design: Randomized controlled trial. Methods: All subjects were randomly divided into three groups where thirteen subjects were in the additional weight aquatic exercise group, twelve subjects in the aquatic exercise group, and fifteen subjects in the control group. Subjects received a graded aquatic exercise program for 30 minutes, with 3 sessions per week for 6 weeks, and subjects in all groups received conventional physical therapy. All subjects were assessed with the Medical Research Council (MRC), the Berg Balance scale (BBS), Timed Up and Go test (TUG), and 10-meter walk test (10MWT) pre and post intervention. Results: The MRC, BBS, TUG, and 10MWT scores significantly improved post-intervention (p<0.05), and the control group also had significantly improved in all areas post-treatment (p<0.05). In addition, it has been confirmed that the additional weight aquatic exercise group had significantly improved in MRC, BBS, and TUG scores compared with the aquatic exercise and control group (p<0.05). Conclusions: The findings of this study suggested that the additional weight aquatic exercise program improves lower extremity and balance in persons with stroke.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.4
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• pp.1903-1906
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• 2019

Background: Foot drop is a common symptom after stroke and causes walking disorders. Therefore, its proper treatment is important for improving the walking ability of patients with foot drop. Objective: This study aimed to investigate the effects of electrostimulation during walking on the walking ability of patients with foot drop after stroke. Design: Quasi-experial study. Methods: The study enrolled 18 patients with foot drop after stroke. All subjects were assigned to the experimental or control group. The experimental group underwent electric stimulation during walking, while the control group used ankle foot orthoses. Both groups received treatment 20 minutes a day 5 times a week for 4 weeks. Outcome measures were assessed for walking and balance ability using the 10-m walking test (10MWT), 6-min walking test (6MWT), and Timed Up and Go test (TUG) Results: After the intervention, both groups showed significant improvements in 6MWT and TUG results. However, the experimental group showed significantly better improvement on all tests than the control group. Conclusion: The foot drop stimulator effectively improved the walking and balance ability of patients with foot drop after stroke.

• Physical Therapy Korea
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• v.11 no.4
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• pp.31-41
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• 2004

The purpose of this study was to examine the effect of the angle of a wedged insole on knee varus torque during walking. Fifteen healthy subjects were recruited. Knee varus torque was measured using three-dimensional motion analysis (Elite). Knee varus torque was normalized to gait cycle (0%: initial contact; 100%: ipsilateral initial contact) and stance phase (0%: initial contact; 100%: ipsilateral toe off). The average peaks of knee varus torque during the stance phase of the gait cycle according to the different insole angles (10 or 15 degrees) were compared using one-way ANOVA with repeated measures. The results showed that in the early stance phase, the average peak knee varus torque increased significantly for both the medial 10 and 15 degree wedged insole conditions and decreased significantly for both the lateral 10 and 15 degree wedged insole conditions as compared with no insole (p<.05). However, there were no significant differences between the 10 and 15 degree wedged insole conditions with either the medial or lateral wedged insole (p>.05). In the late stance phase, the average peak knee varus torque increased significantly for the medial 10 and 15 degree wedged insole conditions (p<.05), but not for the lateral 10 and 15 degree wedged insole conditions as compared with no insole (p>.05). We suggest that these results may be beneficial for manufacturing foot orthotic devices, such as wedged insoles, to control medial and lateral compartment forces in the knee varus-valgus deformity. Further studies of the effects of wedged insole angle on knee varus torque in patients with medial-lateral knee osteoarthritis are needed.

• The Journal of Korean Physical Therapy
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• v.27 no.6
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• pp.407-412
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• 2015

Purpose: This study aimed to evaluate changes in the balance ability of patients whose head positions were altered due to stroke. Subjects were divided into three groups to determine the effects of the training on dynamic balance and gait. Methods: Forty-two stroke patients were enrolled. The Visual Feedback Training (VFT) group performed four sets of exercises per training session using a Sensoneck device, while the Active Range of Motion (ART) group performed eight sets per training session after receiving education from an experienced therapist. The Visual Feedback with Active Range of Motion (VAT) group performed four sets of active range of motion and two sets of visual-feedback training per session using a Sensoneck device. The training sessions were conducted three days a week for eight weeks. Results: The comparison of changes in dynamic balance ability showed that a significant difference in the total distance of the body center was found in the VFT group (p<0.05) and Significant differences were found according to the training period (p<0.05). The comparison of the 10 m walk test showed that the main effect test, treatment period and interactions between group had statistically significant differences between the three groups (p<0.05). Conclusion: Head-adjustment training using visual feedback can improve the balance ability and gait of stroke patients. These results show that coordination training between the eyes and head with visual feedback exercises can be used as a treatment approach to affect postural control through various activities involving the central nervous system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3658-3665
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• 2010

As the population of elderly people and disabled people are increased, various demands for human welfare using robot system are raised. Especially autonomous rehabilitation system using robot could reduce the human effort while maintaining the its intrinsic efficacy. This study deals with mobile gait rehabilitation system which combined with BWS (Body Weight Support) for training of elderly and handicapped people who suffer the muscle force weakness of lower extremity. BWS which is designed by kinematic analysis of body lifting characteristics and walking guide system are integrated with main control system and wheeled platform. This mobile platform is operated by UCS (User Command System) and autonomous trajectory planning algorithm. Finally, through the EMG (Electromyography) signal measuring and its analysis for subject, performance and feasibility of developed system is verified.

• The Journal of Korean Physical Therapy
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• v.26 no.5
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• pp.296-301
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• 2014

Purpose: The purpose of this study was to investigate the effect of strengthening exercises of hip abductors on muscle strength and ambulation for patients with ACL reconstruction. Methods: The subjects were randomly assigned to the intervention group (general exercise plus strengthening of hip abductors) or the control group (general exercise without the strengthening of hip abductors). Both groups participated in a six-week exercise protocol after the surgery for ACL reconstruction. The knee strength test (quadriceps, hamstring, hip abductor) and gait analysis were performed in pretest and post-test. Results: Muscle strength was measured using the Biodex system III model (Biodex Medical System, Inc, NY, US). The results showed no significant difference in knee strength (quadriceps, hamstring) between the two groups (p>0.05), however, there was a significant difference in hip abductors (p<0.05). The gait analysis was measured with Gaitrite system (CIR System Inc, US). Results of comparison between groups showed a significant increase in the step length of both groups. (p<0.05), and there was a significant difference in the affected leg of the intervention group(p<0.05). Conclusion: Exercise of hip abductors for patients with ACL reconstruction provides significant benefits with respect to improvement of muscle strength in hip abductors, increasing the stride. This result indicates that a training program designed for ACL reconstruction patients should include strengthening of the hip abductor. We think that further study is needed to determine the relationship of hip muscles and knee joint for patients with ACL reconstruction.