• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.452-460
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• 2005

Based on an introduced optimal trajectory planning method, this paper mainly deals with the accuracy analysis during the function approximation process of the optimal trajectory planning method. The basis functions are composed of Hermit polynomials and Fourier series to improve the approximation accuracy. Since the approximation accuracy is affected by the given orders of each basis function, the accuracy of the optimal solution is examined by changing the combinations of the orders of Hermit polynomials and Fourier series as the approximation basis functions. As a result, it is found that the proper approximation basis functions are the $5^{th}$ order Hermit polynomials and the $7^{th}-10^{th}$ order of Fourier series.

• 한국전문물리치료학회지
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• 제24권3호
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• pp.1-9
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• 2017

Background: The method of measuring the walking function of patients with chronic stroke differs depending on patients walking capability and environmental conditions. Objects: This study aimed to demonstrate the influences of walking capacity and environmental conditions on the results of short- and long-distance walk tests in patients with chronic stroke. Methods: Forty patients with chronic stroke volunteered for this study, and allocated to group-1 (<.4m/s, household walking, $n_1=13$), group-2 (.4~.8m/s, limited community ambulation, $n_2=16$), and group-3 (>.8m/s, community ambulation, $n_3=11$) according to their walking capacity. The 10-meter walk test (10MWT) and 6-min walk tests, (6MWT) were used to compare the short- and long-distance walk tests results, which were randomly performed under indoor and outdoor environmental conditions. Results: The comparison of the results obtained under the indoor and outdoor conditions revealed statistically significant differences between the groups in the 6MWT and 10MWT (p<.05). Post-hoc tests' results showed significant differences between groups-1 and -2 and between groups-1 and -3 in the 10MWT, and between group-1 and -3 in the 6MWT. Furthermore, in group-2 the 10MWT and 6MWT results significantly differed between the indoor and outdoor conditions, and the values measured under the indoor and outdoor conditions significantly differed between 10MWT and 6MWT (p<.05). Group-3 showed a significant difference in 10MWT results between the indoor and outdoor conditions (p<.05). Conclusion: These findings suggest that the results of the short- and long-distance walk tests may differ depending on the walking capacity of patients with chronic stroke and the environmental condition under which the measurement is made, and these effects were greatest for the patients with the limited community ambulation capacity.

• 한국운동역학회지
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• 제17권4호
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• pp.27-36
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• 2007

The purpose of this study was to investigate the effect of the upper body in order to increase a propulsive force in the old's walking. The subjects were each 10 males, the latter term of the aged and former term of the aged. There were three walking speeds of slow(about 5km/h), medium(about 6km/h), and maximum speed(about 7km/h). The subjects walking 11m were filmed the 5m section (from 3m to 8m) by 2-video cameras using three dimensional cinematography. And we computed different mechanical quantities and especially computed the relative momentum in order to achieve this study's aim. In this study, we was able to acquire some knowledge. The step length and step frequency increased in proportion to the walking speed, and the faster walking speed, the shorter ratio of supporting time( both legs supporting time/one step length time). When it was one leg support phase, the torso was indicated to generate the momentum in order to produce the propulsive force of walking. The upper and lower body had a cooperative relation for walking such as keeping step rate with the arms to legs and maintaining the body balance. The opposition phase for upward-and-downward direction of the torso and arms in walking was functioned to prevent the increase rapidly toward vertical direction of the center of gravity. The arms had contributed to coordinate the tempo of legs and the posture maintenance of the upper body. And by absorbing the relative momentum from the upper torso with arms to the lower torso, it had the rhythmical movement on upward-and-downward direction reducing the vertical reaction force. On account of the relations of absorption and generation of the propulsive force and the production of vertical impulse in the lower torso when walking by maximum speed, it was showed that the function of lower torso was come up as important problem for the mechanical posture stability and propulsive force coordination.

• 지역사회간호학회지
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• 제17권2호
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• pp.166-175
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• 2006

Purpose: This study was to evaluate the effects of a rehabilitation exercise program on physical function and mental health status in chronic stroke Patients with hemiparesis Method: This study used a single group experimental design with repeated measures. Data collection and intervention were done from August, 2004 to November. 2004 at a community. Participants were fifteen patients (mean age: 68.6), and a 100 meter walking time and box and block tests were conducted at baseline, 4weeks, and post-intervention (8weeks) Activities of daily living and the levels of depression and anxiety were measured by using SCL-90-R at pre and post Intervention. This program consisted of 1 hour individual exercise 3 times a week for 8 weeks, and it focused on stretching, walking, arm and hand exercise, and hand massage. Result: 1. ADL, IADL, and the 100m walking time in the patients were improved compared with baseline. However. box and block tests was not shown significant improvement compared with baseline. 2. Depression and anxiety scores were improved more than that of baseline. Conclusion: The rehabilitation exercise program can be effective in improving physical function and mental health status, and it has a potential for improving Physical health status in Patients with chronic stroke hemiparesis.

• International Journal of Ocean System Engineering
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• 제1권4호
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• pp.222-229
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• 2011

In this paper, we present the concept and main mission of the Crabster, an underwater walking robot. The main focus is on the modeling of drag and lift forces on the legs of the robot, which comprise the main difference in dynamic characteristics between on-land and underwater robots. Drag and lift forces acting on the underwater link are described as a function of the relative velocity of the link with respect to the fluid using the strip theory. Using the translational velocity of the link as the rotational velocity of the joint, we describe the drag force as a function of joint variables. Generalized drag torque is successfully derived from the drag force as a function of generalized variables and its first derivative, even though the arm has a roll joint and twist angles between the joints. To verify the proposed model, we conducted drag torque simulations using a simple Selective Compliant Articulated Robot Arm.

• 한국산학기술학회논문지
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• 제22권5호
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• pp.303-309
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• 2021

본 연구는 보행 훈련시 심박수의 변화에 따라 보행속도를 조절하여 뇌졸중 환자의 심폐기능의 변화를 알아보고자 하였다. 대상자는 만성 뇌졸중 환자 20명을 무작위로 실험군과 대조군으로 분류하여 연구를 진행하였다. 실험군은 심박수 측정기를 착용한 상태로 트레드밀에서 심박수의 변화에 따라 보행속도를 증가 또는 감소시키면서 보행훈련을 실시하였고, 대조군은 대상자의 주관적인 속도에 의해 보행훈련을 실시하였다. 보행훈련 사이에 10분 간격으로 1분씩 휴식시간을 부여했으며 주 3회씩 총 6주간 중재를 실시하였다. 대상자들의 중재이후의 변화를 살펴보기 위하여 폐활량(VC), 호기예비용적(ERV), 흡기예비용적(IRV) 노력성 폐활량(FVC), 1초간 노력성 호기량(FEV1), 최대 호기 속도(PEF)를 측정하여 심폐기능의 변화를 확인하였다. 연구결과 폐활량, 흡기예비용적, 호기예비용적에서 집단과 시기사이에서 상호작용을 나타내었으며 주효과인 집단 및 시기 간 유의한 차이도 나타났다(p<.05), 1초간 노력성 호기량, 노력성 폐활량, 최대 호기속도에서는 그룹과 시기사이에서 상호작용이 나타나지 않았다. 주 효과에서는 집단 간 유의한 차이를 보이지 않았으나(p>.05) 시기 간에는 유의한 차이를 보였다(p<.05). 연구결과 보행과정에서 심박수의 변화에 따라 속도를 변화시켜 훈련을 시행할 경우 심폐기능의 유의한 향상을 보인 것으로 보아 보행 훈련시 속도변화를 통해 훈련을 할 경우 심폐기능의 유의한 변화를 이끌어 낼 수 있을 것으로 판단된다.

• 대한통합의학회지
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• 제10권3호
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• pp.119-129
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• 2022

Purpose : The purpose of the study was to find out the effects of obstacle walking training according on gait and balance in stroke patients. Methods : Twenty-four stroke patients are randomly assigned to experimental group 1 (n=8), experimental group 2 (n=8) and control group (n=8). Experimental group 1 performed unexpected obstacle walking training, experimental group 2 performed fixed obstacle walking training and control group performed non obstacle walking training for 12 minutes per session, 5 times a week for 4 weeks. The gait analyzer G-walk were evaluated using gait cadence, gait velocity, and stride length, balance was evaluated using FES-K and BBS. Results : In within-group comparison of gait cadence, gait velocity and stride length of change, the experimental 1,2 groups showed significant improvements post intervention (p<.05) but control group showed no significant improvement. In between-groups comparison there was significant difference in the change of gait cadence, gait velocity and stride length pre and post intervention. In within-group comparison of FES-K and BBS scores, the experimental 1,2 groups showed significant improvements post intervention (p<.05) but control group showed no significant improvement. In between-groups comparison there was significant difference in the change of FES-K and BBS scores pre and post intervention (p<.05). Conclusion : Obstacle walking training can improve the gait, function and balance of stroke patients and obstacle walking training is effective for improving gait and balance compared to non-obstacle walking training.

• The Journal of Korean Physical Therapy
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• 제27권5호
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• pp.364-368
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• 2015

Purpose: Walking in the dual-task condition is a critical skill for hemiplegic patients to live in real-life situations. The purpose of this study was to compare the effect of dual-task gait training and general gait training on gait parameters and cognitive function in patients with chronic stroke during dual-task walking. Methods: The study included 23 patients with chronic hemiparetic stroke who were randomly divided into experimental (dual-task gait training) and control (general walking training) groups. The 11 subjects in the experimental group and nine subjects in the control group received dual-task gait training (walking while handling a ball, crossing obstacles, picking up various objects, and problem solving simple cognitive tasks and general over-ground gait training, respectively, for 30 minutes per day 5 days per week for 4 weeks. Spatiotemporal parameters and cognitive tasks in the dual-task gait condition were measured. Statistical analysis of the changes between the pre- and post-intervention measurement variables was performed using ANCOVA. Results: In the gait condition under cognitive tasks, the changes pre- and post-intervention in gait velocity, stride length, double support limb, and step symmetry were significantly greater in the dual-task gait training group; however, the dual-task gait training group showed no significant improvement compared to the general gait training group in terms of the assessment of cognitive tasks. Conclusion: The findings suggest that dual-task gait training may be beneficial for walking ability in dual-task walking condition.

• 한국기계가공학회지
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• 제9권6호
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• pp.87-94
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• 2010

In this paper, a new simulator of the biped robot for planning walking patterns was showed. And this simulator(MHBiped) is able to not only visualize the plan of patterns but also verify whether a biped robot design is suitable. In addition, MHBipd can modify various kinds of walking parameters and the trajectory of biped robot. Therefore, a new biped robot can be designed easily by the this simulator before you apply to a robot. As a result, a well-balanced parameters of walking patterns watching the movement of CG and ZMP can be obtained. Walking patterns should be changed according to both the existence of obstacles and conditions of ground and it can be described by the trajectory of hip and ankles. All those trajectorys can be also obtained by the cubic spline functions and the way of modeling walking patterns. The results of simulator, the movement function of CG and ZMP, the cubic spline functions and modeling of biped robot were introduced in this paper. And the effectiveness of this simulator was confirmed by the simulations.

• 대한물리의학회지
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• 제14권1호
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• pp.35-41
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• 2019

PURPOSE: This study examined the effects of a vestibular stimulation training program on the walking ability of chronic stroke patients over a six month period. METHODS: Forty stroke patients were enrolled in this study. The patients were divided randomly into a control group (n=20) and experimental group (n=20). A general exercise program was applied to Group I and vestibular stimulation training was applied to Group II(30 min, three times a week for six weeks). The changes in straight walking ability, curved walking ability, and functional walking ability were measured using a 10 m walking test figure-of-eight-walking test, and dynamic gait index, respectively. The measures before and after the program were compared using a paired t-test for a comparison of each group and an independent t-test for a comparison between groups. RESULTS: The changes in each group were examined according to the measurement period. The Experimental group showed significant functional improvement in all three tests after the vestibular stimulation training program, but the control group did not show significant improvement in any of the tests after the general exercise program. A comparison of the changes between groups revealed the experimental group to show significantly higher improvement than the control group in all tests. CONCLUSION: The vestibular stimulation training program helps improve the gait function of stroke patients. Based on the results of this study, it is expected that various vestibular stimulation training programs will be developed and applied in a range of places.