• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.95-96
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• 2007

• Journal of the Korean Society of Physical Medicine
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• v.9 no.1
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• pp.69-74
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• 2014

PURPOSE: The aim of this study is to compare the spatio-temporal gait parameters between paretic and non-paretic limb while stepping over the different obstacle's heights in subjects with stroke. METHODS: Nine subjects with stroke were participated in this study. Subjects were asked to step over obstacles with a different height. 8 camera motion analysis system(Motion Analysis Corporation, Santa Rosa, USA) was used to measure spatio-temporal parameters. The two way repeated measurement ANOVA was used to compare spati-temporal gait parameters between paretic and non-paretic limbs while stepping over a different obstacle's height(0cm, 10cm, 20cm). RESULTS: Step width, velocity, single supoort time, and double support time were not different among obstacle's height(p>0.05) but stride length, step length, and cadence were significantly different(p>0.05). In stride length, cadence, and double support time, the interactions between obstacle's heights and limbs were not different(p>0.05) but it was significantly different in velocity, step length, and single support time(p<0.05). Velocity, stride length, cadence, and double support times were not different between paretic limb and non-paretic limb(p>0.05) but step length and single support times were significantly different between paretic limb and non-paretic limb(p<0.05). CONCLUSION: These results show that there are differences with spatio-temporal gait parameters among obstacle's heights and between paretic and non-paretic limb during obstacle crossing in subjects with stroke.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2660-2664
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• 2003

In this study, the concept of autonomous mobility is applied to a medical service robot. The aim of the development of the service robot is for the elderly assisting walking rehabilitation. This study aims that the service robot design parameter is proposed in ergonomic view. The walking assistant path pattern is derived from analyzing the elderly gait analysis. A lever is installed in the AMR in order to measure the pulling force and the leading force of the elderly. A lever mechanism is applied for walking assistant service of the AMR. This lever is designed for measuring the leading force of the elderly. The elderly adjusts the velocity of the robot by applying force to the lever. The action scope and the service mechanism of the robot are developed for considering and analyzing the elderly action patterns. The ergonomic design parameters, that is, dimensions, action scope and working space are determined based on the elderly moving scope. The gait information is acquired by measuring the guide lever force by load cells and working pattern by the electromyography signal.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.297-302
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• 2013

Purpose: This study was conducted in order to investigate the kinematic gait parameter of lower extremities with different gait conditions (level walking, stair, ramp) in hemiplegic patients. Methods: Ten hemiplegic patients participated in this study and kinematic data were measured using a 3D motion analysis system (LUKOtronic AS202, Lutz-kovacs-Electronics, Innsbruk, Austria). Statistical analysis was performed using one-way repeated measure of ANOVA in order to determine the difference of lower extremity angle at each gait phase with different gait conditions. Results: Affected degree of ankle joint in the heel strike phase showed significant difference between level walking and climbing stairs, and toe off phase showed significant difference between level walking and climbing stairs, ramps, and climbing stairs. Affected degree of knee joint showed no significant difference in all attempts. Affected degree of hip joint in the toe off phase showed significant difference between level walking, ramps and stairs, and climbing ramps. Swing phase showed significant difference between sides for level walking and stairs, climbing ramps. Affected ankle joint of heel strike and toe off, and affected hip joint of toe off and the maximum angle of swing phase in the angle was increased. Unaffected side of the ankle joint, knee joint, and hip joint showed a significant increase in walking phase. Conclusion: These findings indicate that compared with level walking, different results were obtained for joint angle of lower extremity when climbing stairs and ramps. In hemiplegia patient's climbing ramps, stairs, more movement was observed not only for the non-affected side but also the ankle joint of the affected side and hip joint. According to these findings of hemiplegic patients when climbing stairs or ramps, more joint motion was observed not only on the unaffected side but also on the affected side compared with flat walking.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.435-448
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• 2009

The purpose of this study was to investigate the kinemaitc gait parameter of lower extremities with different gait conditions(level walking, stairs, ramp) in old adults. Fourteen healthy older adults participated in this study and kinematic data were measured using 3D motion analysis system(Vicon, Oxford Metrics, England). Statistical analysis was used one-way ANOVA to know the difference of lower extremities angle at each gait phase with a different gait conditions. In sagittal plane, pelvic anterior tilt increased in stairs and ramp climbing and hip and knee flexion increased in stairs climbing but ankle dorsiflexion increased in ramp climbing. In frontal plane, pelvic was up in stairs and hip abduction and adduction more changed in stairs climbing than level walking. Knee varus and ankle inversion increased in stair climbing. In horizontal plane, pelvic internal rotation increased in stairs and ramp climbing and knee internal rotation increased in stairs climbing but ankle external rotation increased in stairs climbing. This results was shown that the stairs and ramp climbing changed the kinematic gait parameters of lower extremities in healthy old adults.

• Structural Engineering and Mechanics
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• v.46 no.2
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• pp.179-196
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• 2013

An experimentally measured single footfall trace (SFT) from a walking subject needs to be extended into a continuous force curve, which can then be used as load for floor vibration serviceability assessment, or on which further analysis like discrete Fourier transform can be conducted. This paper investigates the accuracy, applicability and parametrical sensitivity of four extension methods, Methods I to IV, which extends the SFT into a continuous time history by the walking step rate, stride time, double support proportion and the double support time, respectively. Performance of the four methods was assessed by comparing their results with the experimentally obtained reference footfall traces in the time and frequency domain, and by comparing the vibrational response of a concrete slab subjected to the extended traces to that of reference traces. The effect of the extension parameter on each method was also explored through parametrical analysis. This study finds that, in general, Method I and II perform better than Method III and IV, and all of the four methods are sensitive to their extension parameter. When reliable information of walking rate or gait period is available in the test, Methods I or II is a better choice. Otherwise, Method III, with the suggested extension parameter of double support time proportion, is recommended.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.645-650
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• 2003

Legged robots can avoid an obstacle by crawling-over or striding, according to the obstacle’s nature and the current state of the robot. Thus, it can be observed that the mobility efficiency to reach a destination is improved by such action. Moreover, if robots have many legs like 4-legged or 6-legged types, then the robot movement range is affected by the order of swing leg. In this paper, the avoidance action of a quadruped robot is generated by a neural network (NN) whose inputs are information on the position of the destination, the obstacle configuration and the robot's self-state. To realize a free gait in static walking, the order of swing leg is determined using an another NN whose inputs are the amount of movements and the robot’s self-state. The design parameter of the latter NN is adjusted by using genetic algorithm (GA).

• The Journal of Korean Physical Therapy
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• v.21 no.3
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• pp.75-80
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• 2009

Purpose: The purpose of this study was to examine the effect of an obstacle height on the balance control of older adults while stepping over an obstacle from a position of quiet stance. Methods: Fifteen community-dwelling healthy older adults (mean age, $74.4\pm4.27$ yrs; age range, 67-82 yrs) volunteered to participate in this study. The subjects performed gait initiation (GI) and they stepped over obstacles of two different heights (10 cm and 18 cm) at a self-paced speed from a position of quiet stance. Their performance was assessed by recording the changes in the displacement of the COP in the anteroposterior (A-P) and mediolateral (M-L) directions using a force platform. Results: The M-L displacement of the COP significantly increased for an 18 cm obstacle height condition as compared to the GI and a 10 cm obstacle height condition (p<0.01). Furthermore, the M-L displacement of the COP for a 10 cm high obstacle was significantly greater for that for the GI (p<0.01). However, the mean of the A-P displacement of the COP was similar between the stepping conditions for the A-P displacement of the COP (p>0.05). Conclusion: This study suggests that the M-L COP displacement could be a better parameter to identify the dynamic balance control in older adults when negotiating obstacles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2989-2995
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• 2014

This study was to performed to get the reference data of the kinematic parameters for normal subjects according to the arm movement type. Forty-five normal subjects participated in this study and preformed four sequence according to the arm movement type : normal arm movement, one arm movement, no arm movement, fitness arm movement. The study data was collected from June to August 2010. The kinematic data were measured using Vicon motion system 6MX3 cameras while each subjects walked through a 10m walkway. There were significant differences according arm movement type in the kinematic parameters such as range of motion (ROM) of the right pelvic, hip in sagittal plane, and ROM of the pelvic, hip, lumbar in coronal plane and ROM of the pelvic, thoracic, lumbar in transverse plane. This study can be utilized as the basic reference data in gait analysis for patients with pathologic gaits.

• Physical Therapy Korea
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• v.26 no.1
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• pp.1-7
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• 2019

Background: The Microsoft Kinect which is a low-cost gaming device has been studied as a promise clinical gait analysis tool having satisfactory reliability and validity. However, its accuracy is only guaranteed when it is properly positioned in front of a subject. Objects: The purpose of this study was to identify the error when the Kinect was positioned at a $45^{\circ}$ angle to the longitudinal walking plane compare with those when the Kinect was positioned in front of a subject. Methods: Sixteen healthy adults performed two testing sessions consisting of walking toward and $45^{\circ}$ obliquely the Kinect. Spatiotemporal outcome measures related to stride length, stride time, step length, step time and walking speed were examined. To assess the error between Kinect and 3D motion analysis systems, mean absolute errors (MAE) were determined and compared. Results: MAE of stride length, stride time, step time and walking speed when the Kinect set in front of subjects were investigated as .36, .04, .20 and .32 respectively. MAE of those when the Kinect placed obliquely were investigated as .67, .09, .37, and .58 respectively. There were significant differences in spatiotemporal outcomes between the two conditions. Conclusion: Based on our study experience, positioning the Kinect directly in front of the person walking towards it provides the optimal spatiotemporal data. Therefore, we concluded that the Kinect should be placed carefully and adequately in clinical settings.