• 한국컴퓨터그래픽스학회논문지
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• 제1권2호
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• pp.201-212
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• 1995

This paper presents a new method of dynamics-based synthesis of bipedal, especially human, walking. The motion of the body at a time point is determined by ground reaction force and torque under the support foot and joint torques of the body at that time point. Motion synthesis involves specifying conditions that constrain ground reaction force and torque, and joint torques so that a given desired motion may be achieved. There are conditions on a desired motion which end-users can think of easily, e.g. the goal position and orientation of the swing foot for a single step and the time period of a single step. In this paper, we specify constraints on the motion of the support foot, which end-users would find difficult to specify. They are constraints which enforce non-sliding, non-falling, and non-spinning the support foot. They are specified in terms of joint torques and ground reaction force and torque. To satisfy them, both joint torques and ground reaction force and torque should be determined appropriately. The constraints on the support foot themselves do not give any good clues as to how to determine ground reaction force and torque. For that purpose, we specify desired trajectories of the application point of vertical ground reaction force (ground pressure) and the application point of horizontal ground reaction (friction) force. The application points of vertical pressure and friction force are good control variables, because they are indicators to kinds of walking motions to synthesize. The synthesis of a bipedal walking motion, then, consists of finding a trajectory of joint torques to achieve a given desired motion, so that the constraints are satisfied under the condition of the prescribed center of pressure and center of friction. Our approach is distinguished from many other approaches, e.g. the inverted-pendulum approach, in that it captures and formulates dynamics of the support foot and reasonable constraints on it.

• 한국운동역학회지
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• 제25권4호
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• pp.401-412
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• 2015

Objective : The purpose of this study is to evaluate the effects of hip joint exercises and orthotics on RCSP, ankle's range of motion, and core muscle strength of middle school students with pes planus. Method : Out of the original pool of 200 students, 60 students with pes planus (RCSP < -2) were selected for the study. The selected 60 students were then divided into four groups. The first group was a combined orthotics and exercise group (12 students), the second was the orthotics-only group (9 students), the third was the exercise-only group (8 students), and the last was the control group (10 students). Exercise groups worked out twice a week for 60 minutes per session over 8 weeks. The independent variables were corrective hip joint exercises and orthotics. The dependant variables consisted of kinematic and kinetic variables. The kinematic variables were RCSP, and ankle's range of motion (dorsiflexion and plantarflexion). The kinetic variables were muscles forces that consist in core muscle strength, which are hip joint adduction, abduction, and flexion muscles forces. Statistical analysis was performed via SPSS 18.0 with multivariate analysis of covariance (MANCOVA) and a paired t-test was used. Results : The left foot was more responsive to the treatments, both exercise and orthotics, than the right foot. RCSP improved significantly in the left foot for the first and third groups. Only the first group significantly improved hip joint adduction, abduction, and flexion muscles' strengths. As for the ankle's range of motion of the left foot, plantarflexion showed improvement when treated with exercise, orthotics, or both. Conclusion : This study found that exercise is more effective in correcting RCSP and foot orthotics is more effective in reinforcing core muscle strength. Future studies should expand on these results to examine the relationship between the ankle, hip, and pelvis.

• 한국운동역학회지
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• 제28권1호
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• pp.45-54
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• 2018

Objective: The purpose of this study was to investigate the effect of foot strengthening exercise program and functional insoles on joint angle and plantar pressure in elderly women. Thirteen elderly women who were enrolled in a university senior citizens academy of a metropolitan city in 2017 were divided into two groups: exercise group with functional insole (n=7) and exercise group without functional insole (n=6). Method: Three-dimensional motion analysis and Pedar-X were performed to compute the joint angle and the foot plantar pressure, respectively. Two-way repeated measure ANOVA was conducted to compare dependent variables within and between groups. The significance level was set at ${\alpha}=.05$. Results: The range of motion (ROM) of the ankle, knee, and hip joints in the exercise group with functional insole increased significantly more than the exercise group without functional insole. In both the experimental group and the comparison group, the maximum foot plantar pressure and the mean foot plantar pressure were decreased, but the comparison group without functional insole showed more decrease. Since the experimental group demonstrated greater pressure than the comparison group in the contact area (forefoot, midfoot), it was distributed over a greater area. Conclusion: The results of this study suggest that participation in foot strengthening exercises and using a functional insole has more positive effects than foot strengthening exercises alone on the joint angle and plantar pressure in elderly women. Increased foot plantar pressure led to an increased contact area (forefoot, midfoot) for distribution of the foot plantar pressure, but the effect of reducing the maximum and average plantar pressures was incomplete. However, wearing functional insoles along with exercise, could help in improving the stability of the joints, by increasing the range of motion, and could help the elderly in movement of the muscles more effectively, leading to an improvement in gait function.

• 국제물리치료학회지
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• 제3권1호
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• pp.364-369
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• 2012

The purpose of this study was to analyze lower limb muscle activity and 3D motion analysis according to change foot arch height during walking. We selected 9 young and healthy people who have been normal foot. And we selected 7 young and healthy people who have been flatfoot. So, people were divided into 2 groups and walked platform during 2 minutes twice for checked by 3D motion analysis. These data were characterized by EMG measurements of three muscles( tibialis anterior, medial and lateral gastrocnemius) while they were walking. The collected data were analyzed by Independent t test using the SPSS statistics program(Ver 12.0). In foot arch change, there were no significant difference in three muscles 3D motion analysis also found that there were no significant difference in joint angles. In this study was to analyze lower limb muscle activity and 3D motion analysis according to change foot arch, but there were no significant difference in 6 muscles neither joint angles.

• 국제물리치료학회지
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• 제8권1호
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• pp.1084-1089
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• 2017

The purpose of this study was to compare and analyze the difference of the ankle joint movements during landing. Seven adult males voluntarily participated in the study and the average foot size of the subjects was 269.8 mm. Image analysis equipment and the ground reaction force plate (landing type) was used to measure th kinetic variables. As a result of this study, it was confirmed that the vertical ground reaction force peak point appeared once in the barefoot with forefoot, while two peak points appeared in the barefoot and functional shoe foot with rear foot landing. About ankle angle, fore foot landing ankle angle, the average with bare foot landing was $-10.302^{\circ}$ and the average with functional shoe foot landing was $-2.919^{\circ}$. Also about rear foot landing, ankle angle was $11.648^{\circ}$ with bare foot landing and $15.994^{\circ}$ with functional shoe landing. The fore foot landing, ankle joint force analysis produced 1423.966N with barefoot and 1493.264N with functional shoes. But, the rear foot landing, ankle joint force analysis produced 1680.154N with barefoot and 1657.286N with functional shoes. This study suggest that the angle of ankle depends on the landing type and bare foot running/functionalized shod running, and ankle joint forces also depends on landing type.

• The Journal of Korean Physical Therapy
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• 제27권1호
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• pp.24-29
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• 2015

Purpose: The purpose of this study was to investigate the effect of lower limb training using a sliding rehabilitation machine on the foot motion and stability in stroke patients. Methods: Thirty participants were allocated to two groups: Training group (n=15) and Control group (n=15). Subjects in the control group received physical therapy for 30 minutes, five times per week, and those in the training group received lower limb training using a sliding rehabilitation machine for 30 minutes, five times per week, with physical therapy for 30 minutes, five times per week, during a period of six weeks. Heel rotation, hallux stiffness, foot balance, metatarsal load, toe out angle, and subtalar joint flexibility were measured by RS-scan. Results: Significant improvement of the foot motion (hallux stiffness, meta load) and the foot stability (toe out angle, subtalar joint flexibility) was observed in the training group. Conclusion: This study demonstrated that lower limb training using a sliding rehabilitation machine is an effective intervention to improve the foot motion and stability.

• 한국멀티미디어학회논문지
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• 제11권11호
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• pp.1575-1591
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• 2008

본 논문에서는 스테레오 카메라로부터 신체 중 발의 3차원 가상 모델을 실시간으로 합성할 수 있도록 동작을 검출하는 새로운 방법을 제안한다. 발에 가상 모델을 같은 위치에 합성하려면 관절의 움직임을 일정하게 추적하는 움직임 검출 과정이 필수적이다. 복잡한 움직임 속에서의 정확한 정합 이 기술이 해결해야 할 가장 중요한 문제이다. 본 논문에서는 두 가지 형태의 마커 그룹을 사용한 동적 정합을 제안한다. 바닥의 평면 정보는 발과 3차원 가상 발 모델의 관계를 조정하고 발의 자세와 위치를 측정한다. 발의 회전은 발등의 중심 골격에 따라 부착한 두 개의 마커(Marker) 그룹을 사용하여 추정했다. 이 논문에서는 제안한 시스템을 직접 구현하고, 다양한 실험을 통해 시스템에 적용된 각 알고리즘의 정확도를 측정했다.

• 한국전문물리치료학회지
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• 제10권1호
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• pp.77-95
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• 2003

Many factors affect foot and ankle biomechanics during walking, including gait speed and anthropometric characteristics. However, speed has not been taken into account in foot kinematics and kinetics during walking. This study examined the effect of walking speed on foot joint motion and peak plantar pressure during the walking phase. Eighty healthy subjects (40 men, 40 women) were recruited. Maximal dorsiflexion and excursion were measured at the first metatarsophalangeal joints during walking phase at three different cadences (80, 100, and 120 step/min) using a three dimensional motion analysis system (CMS70P). At the same time, peak plantar pressure was investigated using pressure distribution platforms (MatScan system) under the hallux heads of the first, second, and third metatarsal bones and heel. Maximal dorsiflexion and excursion and excursion at the ankle joint decreased significantly with increasing walking speed. Peak plantar pressure increased significantly under the heads of the first of the first, second, and third metatarsal bones, and heel with increasing walking speed: three was no change under the hallux. There were no significant changes in maximal dorsiflexion or excursion at the first metatarsophalangeal joint. The results show that walking speed should be considered when comparing gait parameters. The results also suggest that slow walking speeds may decrease forefoot peak plantar pressure in patients with peripheral neuropathy who have a high risk of skin breakdown under the forefoot.

• 대한의용생체공학회:의공학회지
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• 제24권6호
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• pp.495-500
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• 2003

본 연구의 목적은 컴퓨터 그래픽 모델을 사용하여 보행 시 족부 관절의 기구학적 특성을 알아보는 것이었다. 모델에서 모든 관전은 단일중심(monocentric), 1 자유도 힌지 관절로 구성되었다. 보행 시 족부의 모션데이터는 4대의 카메라를 사용한 모션측정기로 얻었으며, 이 모션데이터를 피험자의 밭의 크기에 맞게 스케일링된 모델에 입력하여 시뮬레이션을 수행하였다. 첫 번째 발목발허리관절(tarsometatarsal joint)의 운동 범위(range of motion)는 $-8^{\circ}\;\~\;-13^{\circ}$ 이었으며, 발허리발가락관절(metatarsophanlangeal joint)에서의 운동범위는 $-13^{\circ}\;\~\;-48^{\circ}$ 이었다. 발목발허리관절과 발허리발가락관절에서의 기구학적인 데이터는 이전 연구와 비교했을 때 비슷한 경향을 나타내었다. 따라서 본 연구에서 제시하는 컴퓨터 그래픽을 기반으로 한 족부 모델링은 족부 관절의 생체역학적 해석을 위한 유용한 방법이라 할 수 있을 것이다.

• 대한기계학회논문집A
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• 제33권9호
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• pp.886-891
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• 2009

One of the important functions of prosthetic foot is the foot inversion-eversion which is so important when walking on uneven surfaces. The aim of our study was to evaluate the effect of foot eversion angle especially on knee and ankle joint for transtibial amputees by motion analysis. The experimental data were collected from three transtibial amputees and then ten healthy individuals. To simulate walking on side sloping ground, we used custom-made slope (5, 10, 15 degrees). Motion analysis was performed by 3-dimensional motion analyzer for 6 dynamic prosthetic feet. The results showed that knee abduction moments of amputated leg were decreased but those of sound leg were mainly increased as foot eversion angle increased. And ankle abduction moments of sound leg were inconsistent in magnitude and tendency between control and experimental group. Therefore foot eversioncharacteristics should be considered to develop advanced prosthetic foot.