• 한국정밀공학회지
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• 제26권5호
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• pp.96-103
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• 2009

This paper describes a humanoid robot's intelligent foot with two six-axis force/moment sensors. The developed humanoid robots didn't get the intelligent feet for walking on uneven surface safely. In order to walk on uneven surface safely, the robot should measure the reaction forces and moments applied on the sales of the feet, and they should be controlled with the measured the forces and moments. In this paper, an intelligent foot for a humanoid robot was developed. First, the body of foot was designed to be rotated the toe and the heel to all directions, second, the six-axis force/moment sensors were manufactured, third, the high-speed controller was manufactured using DSP(digital signal processor), fourth, the humanoid robot's intelligent foot was manufactured using the body of foot, two six-axis force/moment sensors and the high-speed controller, finally, the characteristic test of the intelligent foot was carried out. It is thought that the foot could be used for a humanoid robot.

• 한국정밀공학회지
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• 제31권10호
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• pp.913-922
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• 2014

This paper describes design of a robotic above-knee prosthetic leg which is powered by electrical motors. As a special feature, the robotic prosthetic leg has enough D.O.F.s. For mimicking the human leg, the robotic prosthetic leg is composed of five joints. Three of them are called 'active joint' which is driven by electrical motors. They are placed at the knee-pitch-axis, the ankle-pitch-axis, and the an! kle-roll-axis. Every 'active joint' has enough torque capacity to overcome ground reaction forces for walking and is backlashless for accurate motion generation and high-performance balance control. Other two joints are called 'passive joint' which is activating by torsion spring. They are placed at the toe part and designed by Crank-rocker mechanism using kinematic design approach. In order to verify working performance of the robotic prosthetic leg, we designed a gait trajectory through motion capture technique and experimentally applied it to the robot.

• 한국정밀공학회지
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• 제32권3호
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• pp.285-292
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• 2015

This paper presents a wireless ground reaction force (GRF) sensing system for ambulatory GRF recording. The system is largely divided into three parts: force sensing modules based on optical sensor, outsole type frame, and embedded system for wireless communication. The force sensing module has advantages of the low height, robustness to the moment interference, and stable response in long term use. In simulation study, the strain and stress properties were examined to satisfy the requirements of the GRF sensing system. Four sensing modules were mounted on the toe, ball, and heel of foot shaped frame, respectively. The GRF signals were extracted using Micrpcontroller unit and transferred to the smart phone via Bluetooth communication. We measured the GRF during the normal walking for the validation of the continuous recording capability. The recorded GRF was comparable to the off the shelf stationary force plate.

• The Journal of Korean Physical Therapy
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• 제22권3호
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• pp.49-53
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• 2010

Purpose: The purpose of this study was to investigate the plantar pressure distribution between the affected and unaffected side in adult hemiplegia during gait with the use of a quad-cane. Methods: Thirty-four stroke patients from 34 to 83 years of age were enrolled in this study, and in random order, all patients were asked to walk at their most comfortable speed three times along a walkway with the use of quad-cane over a period of three days. Plantar pressure distribution was measured with regard to foot contact pattern and center of pressure (CoP) trajectories during the stance phase, progressing from heel-strike to toe-off. The F-scan system was used to compare the foot pressure of the affected and unaffected sides. Results: A significant reduction in the total contact area, the width of fore foot (FF) and hind foot (HF), and anterior/posterior (AP) CoP trajectory of the affected side was found. However, contact pressure of the hind foot on the affected side during walking increased when compared to that on the unaffected side. Conclusion: We demonstrated that plantar pressure distribution on the affected side of adult hemiplegia patients was generally poorer than that on the unaffected side when these patients walked with cane assistance. However, the use of a quad-cane was shown to increase contact pressure of the hind foot on the affected side because weight can be borne on the affected side during heel-strike with use of the cane.

• 한국산학기술학회논문지
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• 제10권12호
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• pp.3833-3838
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• 2009

본 논문은 산업용 로봇을 이용하여 운동화의 특성을 측정하는 측정장비를 소개한다. 여기서 사용된 로봇은 6관절의 퓨마타입 로봇(삼성전자의 FARA AT2 모델)을 인간의 보행 동작을 구현할 수 있도록 보완하였다. 보행 동작은 고속카메라로 분석한 후, 로봇 관절각들을 추출하여 동작구현에 사용한다. 3가지 종류의 경도 아웃솔(신발 겉창)로 만들어진 신발 시편을 준비하고, 이 로봇 시스템을 이용하여 걸음동작을 구현하여 신발에 따른 지면 충격력을 측정한다. 걸음동작에서 발생하는 발 앞축 부분을 굽히기 위해 요구되는 굽힘 모멘트의 측정과 걸음동작에서 발생하는 요동현상의 측정에 사용한다. 동일한 압축변형을 유지하도록 시스템을 설정하고, 신발을 측정한 결과 아웃솔의 경도에 따라 지면반력의 크기는 선형적으로 증가하는 추세가 관찰되었다. 또한 굽힘 모멘트와 요동현상 역시 아웃솔의 경도에 따라 선형적으로 증가하는 추세가 관찰되었다. 상기의 몇 가지 실험을 통하여, 본 로봇 시스템은 일관성 있는 실험결과를 제공하였으며, 따라서 산업용 로봇을 이용하여 신발의 유용한 특성 정보 도출이 가능하며, 추후 신발설계의 활용에 대한 가능성을 보여준다.

• 한국운동역학회지
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• 제19권2호
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• pp.237-244
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• 2009

본 연구는 처네를 사용하고 보행을 하는 동안 처네의 사용 방법에 따른 족저 압력의 변화와 목, 허리 및 다리 근육의 활성도를 알아 보기 위하여 실시하였으며 이를 위하여 족저 영역별 최고 압력과 근육 활성도를 중심으로 자료를 수집하여 분석하였다. 영아를 양육하고 있는 허리와 다리 및 목의 근골격계 문제가 없는 20명의 건강한 젊은 여성을 대상으로 전방 처네 사용, 후방 처네 사용, 일반 보행을 하는 동안 입각기 발의 영역별 족저 최고 압력과 목, 허리 및 다리 근육의 활성도를 측정하였다. 족저 압력의 측정은 RS-scan system을 이용하였으며, 근육 활성도는 ProComp InfinitiTM를 이용하였다. 처네 사용 방법에 따라 수집된 자료를 일원배치분산분석을 이용하여 분석하였다. 본 연구를 통하여 전방 처네 사용 시 허리 근육의 활성도와 엄지 발가락 영역의 압력이 유의하게 증가한다는 것을 알 수 있었고, 후방 처네 사용 시 목 근육의 활성도와 발허리 영역의 압력이 유의하게 증가하였다. 따라서 본 연구에서는 처네의 사용 방법이 발의 구조와 기능 그리고 근육 활성도에 영향을 미친다는 것을 확인 할 수 있었다.

• 인터넷정보학회논문지
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• 제21권6호
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• pp.41-50
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• 2020

The consequences of wearing high heels can be different according to the heel height, gait speed, shoe design, heel base area, and shoe size. This study aimed to focus on the knee extension and flexion range of motion (ROM) during gait, which were challenged by wearing five different shoe heel types and two different self-selected gait speeds (comfortable and fast) as experimental conditions. Measurement standards of knee extension and flexion ROM were individually calibrated at the time of heel strike, mid-stance, toe-off, and stance phase based on the 2-minute video recordings of each gait condition. Seven healthy young women (20.7 ± 0.8 years) participated and they were asked to walk on a treadmill wearing the five given shoes at a self-selected comfortable speed (average of 2.4 ± 0.3 km/h) and a fast speed (average of 5.1 ± 0.2 km/h) in a random order. All of the shoes were in size 23.5 cm. Three of the given shoes were 9.0 cm in height, the other two were flat shoes and sneakers. A motion capture software (Kinovea 0.8.27) was used to measure the kinematic data; changes in the knee angles during each gait. During fast speed gait, the knee extension angles at heel strike and mid-stance were significantly decreased in all of the 3 high heels (p<0.05). The results revealed that fast gait speed causes knee flexion angle to significantly increase at toe-off in all five types of shoes. However, there was a significant difference in both the knee flexion and extension angles when the gait in stiletto heels and flat shoes were compared in fast gait condition (p<0.05). This showed that walking fast in high heels leads to abnormal knee ROM and thus can cause damages to the knee joints. The findings in this preliminary study can be a basis for future studies on the kinematic changes in the lower extremity during gait and for the analysis of causes and preventive methods for musculoskeletal injuries related to wearing high heels.

• 한국운동역학회지
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• 제18권2호
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• pp.1-9
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• 2008

본 연구는 장애물을 넘는 동안 장애물의 높이 변화가 보행 시 족저압에 미치는 영향을 알아보기 위해 실시하였으며 이를 위해 족저 최고 족저압과 최대 힘, 압력 중심의 이동 경로를 중심으로 자료를 수집하여 분석하였다. 근골격계에 문제가 없는 열여섯 명의 건강한 젊은 성인이 이 연구에 참여하여 맨발로 각각 평지, 10cm, 20cm 그리고 30cm의 장애물을 넘는 동안 입각기 발의 족저 최고 족저압과 최대 힘, 압력중심 이동경로를 측정하였다. 측정은 Tekscan사의 Footmat system을 이용하였으며, 대상자의 발을 일곱 개의 영역(두 개의 발가락 영역, 세 개의 전족부 영역, 한 개의 중족부와 후족부 영역)으로 나누어 수집한 자료를 일원배치분산분석을 이용하여 분석하였다. 본 연구를 통해 높이가 다른 여러 가지 장애물을 넘을 때, 입각기 동안 족저의 영역별 최고 족저압과 최대 힘은 발가락부위에서 유의하게 증가하는 것을 알 수 있었고 후족부위에서는 감소하였다. 그리고 장애물의 높이가 높아질수록 압력중심 이동경로가 짧아지면서 전족부에서 외전하는 경향을 볼 수 있었다. 따라서 본 연구에서는 장애물 보행 시 장애물의 높이가 발의 구조와 기능에 영향을 미친다는 것을 확인할 수 있었다.

• 한국운동역학회지
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• 제15권4호
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• pp.153-168
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• 2005

The purposes of this study were to determine the influence of midsole hardness and sole thickness of sports shoes on ball flex angle and position with increment of running velocity. The subjects employed for this study were 10 college students who did not have lower extremity injuries for the last one year and whose running pattern was rearfoot striker of normal foot. The shoes used in this study had 3 different midsole hardness of shore A 40, shore A 50, shore A 60 and 3 different sole thickness of 17cm, 19cm, 21cm. The subjects were asked to run at 3 different speed of 2.0m/sec, 3.5m/sec, 5.0m/sec and their motions were videotaped with 4 S-VHS video cameras and 2 high speed video cameras and simultaneously measured with a force platform. The following results were obtained after analysing and comparing the variables. Minimum angle of each ball flex position were increased with the increment of running velocity and shoe sole thickness(P<0.05), but mid-sole hardness did not affect minimum ball flex angle. The position which minimum angle was shown as smallest was 'D'. Midsole hardness and sole thickness did not affect time to each ball flex minimum angle, total angular displacement of ball flex angle, and total angular displacement of torsion angle(P<0.05). The position which minimum angle was appeared to be earliest was similar at walking velocity, and E and F of midfoot region at running velocity. Total angular displacement of ball flex position tended to increase as shifted to heel. It was found that running velocity had effects on ball flex angle variables, but shoe sole thickness partially affected. It would be considered that running velocity made differences between analysis variables at walking and running when designing shoes. Also, it was regarded that shoes would be developed at separated region, because ball flex angle and position was shown to be different at toe and heel region. It is necessary that midsole hardness and thickness required to functional shoes be analyzed in the further study.

• 한국운동역학회지
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• 제21권4호
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• pp.495-501
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• 2011

The purpose of this study was to develop the inertial sensor module system to detect gait event using single angular rate sensor(gyroscope), and evaluate the accuracy of this system. This sensor module is attached at the heel and gait events such as heel strike, foot flat, heel off, toe off are detected by using proposed automatic event detection algorithm. The developed algorithm detect characteristics of pitch data of the gyroscope to find gait event. To evaluate the accuracy of system, 3D motion capture system was used and synchronized with sensor module system for comparison of gait event timings. In experiment, 6 subjects performed 5 trials level walking with 3 different conditions such as slow, preferred and fast. Results showed that gait event timings by sensor module system are similar to that by kinematic data, because maximum absolute errors were under 37.4msec regardless of gait velocity. Therefore, this system can be used to detect gait events. Although this system has advantages of small, light weight, long-term monitoring and high accuracy, it is necessary to improve the system to get other gait information such as gait velocity, stride length, step width and joint angles.