• 한국전문물리치료학회지
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• 제27권4호
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• pp.227-232
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• 2020

Background: Hallux valgus (HV) is a foot deformity developed by mediolateral deviation of the first metatarsophalangeal joint. Although various foot-toe orthoses were used to correct the HV angle, verification of the effects of kinetics variables such as ground reaction force (GRF) through three-dimensional (3D) gait analysis according to the various type of orthoses for HV is insufficient. Objects: This study aimed to investigate the effect of soft and hard types of foot and toe orthoses to correct HV deformity on the GRF in individuals with HV using 3D motion analysis system during walking. Methods: Twenty-six subjects participated in the experiment. Participants had HV angle of more than 15° in both feet. Two force platforms were used to obtain 3D GRF data for both feet and a 3D motion capture system with six infrared cameras was used to measure exact stance phase point such as heel strike or toe off period. Total walk trials of each participant were 8 to 10, the walkway length was 6 m. Two-way repeated measures ANOVA was used to determine the effects of each orthosis condition on the various GRF values. Results: The late anteroposterior maximal force and a first vertical peak force of the GRF showed that the hard type orthosis condition significantly increased GRF compared to the other orthosis conditions (p < 0.05). Conclusion: There were significant effects in GRF values when wearing the hard type foot orthosis. However, the hard type foot orthosis was uncomfortable to wear during walking. Therefore, it is necessary to develop a new foot-toe orthosis that can compensate for these disadvantages.

• Journal of Trauma and Injury
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• 제32권3호
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• pp.187-193
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• 2019

Many techniques have been developed for reconstruction of the hand; however, less attention has been paid to foot reconstruction techniques. In particular, reconstruction of the forefoot and big toe has been considered a minor procedure despite the importance of these body parts for standing and walking. Most of the weight load on the foot is concentrated on the forefoot and big toe, whereas the other toes have a minor role in weight bearing. Moreover, the forefoot and big toe are important for maintaining balance and supporting the body when changing directions. Recently, attention has been focused on the aesthetic appearance and functional aspects of the body, which are important considerations in the field of reconstructive surgery. In patients for whom flap reconstruction in the forefoot and big toe is planned, clinicians should pay close attention to flap survival as well as functional and cosmetic outcomes of surgery. In particular, it is important to assess the ability of the flap to withstand functional weight bearing and maintain sufficient durability under shearing force. Recovery of protective sensation in the forefoot area can reduce the risk of flap loss and promote rapid rehabilitation and functional recovery. Here, we report our experience with two cases of successful reconstruction of the forefoot and big toe with a sensate anterolateral thigh flap, with a review of the relevant literature.

• 한국정밀공학회지
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• 제28권4호
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• pp.446-454
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• 2011

In terms of the anatomy and mechanics of the human foot, a flexible robot foot with toes and heel joints is designed for a bipedal walking robot. We suggest three design considerations in determining foot design parameters which are critical for walking stability. Those include the position of the frontal toe, the stiffness of toes and heels, and the position of the ankle joint. Compared with the conventional foot with flat sale, the proposed foot is advantageous for human-like walking due to the inherent structural flexibility and the reasonable parameter values. Simulation results are provided to determine the design parameters and also show that the proposed foot enables smaller energy consumption.

• 한국전문물리치료학회지
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• 제13권2호
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• pp.16-25
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• 2006

The aim of this study was to investigate the kinematics of young adults during descent ramp climbing at different inclinations. Twenty-three subjects descended four steps at four different inclinations (level, $-8^{\circ}$, $-16^{\circ}$, $-24^{\circ}$). The 3-D kinematics were measured by a camera-based Falcon System. The data were analyzed using one-way ANOVA and the Student-Newman-Keuls test. The kinematics of descent ramp walking could be clearly distinguished from the kinematics of level walking. On a sagittal plane, the ankle joint was more plantar flexed at initial contact with $-16^{\circ}/-24^{\circ}$ inclination, was decreased in the toe off position with all inclinations (p<.001),and was decreased at maximum plantar flexion during the swing phase (p<.001). The knee joint was more flexed at initial contact with the $-24^{\circ}$ inclination (p<.001), was more flexed in the toe off position with all inclinations (p<.001), and was more flexed at minimum flexion during stance phase and at maximum flexion during swing phase with $-16^{\circ}$, $-24^{\circ}$ inclination (p<.001). The hip joint was more flexed in the toe off position with $-16^{\circ}$, $-24^{\circ}$ inclination and was deceased at maximum extension during stance phase with $-16^{\circ}$, $-24^{\circ}$ inclination (p<.05). In the frontal plane, the ankle joint was more everted at maximum eversion during stance phase with $-16^{\circ}/-24^{\circ}$ inclination (p<.01) and was decreased at maximum inversion during swing phase with $-16^{\circ}$, $-24^{\circ}$ inclination (p<.01). The knee joint was more increased at maximum varus during stance phase with $-16^{\circ}/-24^{\circ}$ inclination (p<.001). The hip joint was deceased at maximum adduction during stance phase with $-24^{\circ}$ inclination (p<.05). In a horizontal plane, only the knee joint was increased at maximum internal rotation during stance phase with $-24^{\circ}$ inclination (p<.05). In descent ramp walking, the different gait patterns occurred at an inclination of over $16^{\circ}$ on the descending ramp in the sagittal and frontal planes. These results suggest that there is a certain inclination angle or angular range where subjects do switch between level walking and descent ramp walking gait patterns.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.415-422
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• 2020

본 연구는 노인을 대상으로 상·하지 근력과 보행을 측정한 후 연령에 따른 차이와 상관관계를 살펴보았다. 2019년 6월~7월 사이 65세에서 85세 사이의 남녀 노인 107명이 측정을 끝까지 마쳤으며 기록된 근력(악력, 발가락력, 중둔근력, 대둔근력)과 보행 특성(보속, 보빈도, 보폭, 외발지지기, 양발지지기)으로 통계 분석을 실시하였다. 상·하지 근력은 악력기, 도수근력측정기, 발가락지력기로 측정하였고 관성센서 기반 보행 측정 신발 시스템으로 보행 자료를 획득하였다. 전기 노인(65~74세)과 후기 노인(75~85세) 사이에 근력과 보행 특성은 차이가 없었다. 전·후기 노인에서 악력, 발가락력, 중둔근력, 대둔근력이 일부 보행 특성과 유의한 상관관계를 보였다(p<.05). 중둔근력과 대둔근력이 두 연령대에서 보행 특성과 유의한 상관관계를 악력이나 발가락력보다 많이 보였다. 보속과 악력의 회귀계수는 전·후기 노인 간에 차이가 없었다. 결론적으로 전기 노인보다 후기 노인에서 근력 요인들이 보행 특성을 더 잘 설명하였다. 또한, 악력은 노인 체력를 손쉽게 측정할 수 있는 변인이지만 보속을 포함한 보행 특성을 설명하는데 중둔근력과 대둔근력이 더 유용할 것이다.

• 한국정밀공학회지
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• 제19권7호
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• pp.43-50
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• 2002

This paper presents the new gait implementation of a biped robot with smooth walking using 3-dimensional continuous trunk motion and kick action of ankle joints. Trajectory generation ova trunk is performed not on a unit gait but on a whole walking interval. In applying kick action such as heel-touch or toe-off, varying coordinate system was employed for the simplification of the kinematic analysis. Desired ZMP (zero moment point) is also changed to implement the efficient kick action. As a result, balancing motion of the proposed gait was much more decreased than that of conventional one. Moreover, robot\\`s walking behavior is very smooth, natural and similar to the pace of a human. The walking experiment system is composed of eight AC servo motors and a DSP controller. The walking simulation and the experimental results are shown using the proposed new walking algorithm.

• 대한기계학회논문집A
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• 제21권8호
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• pp.1250-1258
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• 1997

This paper reports on the development of a new foot for a quadrupedal jointed-leg type walking robot. The foot has 2 toes, one at the front and the other at the rear side, for stable landing on uneven ground by point contact. The toes can move up and down independantly, guided by double-wishbone shaped parallel links which enable the lower leg to rotate with respect to a remote center on the ground surface. The motion of each toe is damped by a hydropneumatic shock absorber integrated in the foot in order to absorb the dynamic landing shock. Furthermore, the new foot can reduce the maximum hip joint drive torque by shortening the moment arm length between the hip joint and the landing force vector on the ground. Intensive experiments were carried out in this study by using a one-leg walking model to investigate the soft landing performance of the foot which could be hardly offered by conventional robot feet such as a flat plate with a gimbal type ankle joint. And it was confirmed that the hip joint torque of the leg walking on the flat surface could be reduced remarkably by using the new foot.

• 대한물리의학회지
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• 제7권1호
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• pp.77-85
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• 2012

Purpose : The purpose of this study was to investigate the effects of trunk exercises on the balancing ability of elderly Hansen's disease patients with lower extremity dysfunction. Method : A total of 24 elderly Hansen's disease patients were divided into two groups: 10 without lower extremity dysfunction and 14 with lower extremity dysfunction. The groups exercised for 60 minutes, two days a week, for a total 12 weeks; balancing ability was measured with the one leg standing test, tandem walking test, and timed up-and-go test. The patients were tested and their results were compared both before and after the completion of their exercise programs. Lower extremity dysfunction was assessed according to the following criteria: unilateral foot-drop, toe-loss, and below-knee amputation. Results : After the exercises, participants in both groups showed a positive, statistically significant difference in balance, compared with before the exercises (the one leg standing test, tandem walking test, and timed up-and-go test; p<.05). For comparison purposes, the group with dysfunction and the group without dysfunction were tested before and after the completion of their exercises. Before the exercises, there was a statistically significant difference in the one leg standing test, tandem walking test, and timed up-and-go test (p<.05). However, after the exercises, there was no significant difference in the one leg standing test, tandem walking test, and timed up-and-go test (p>.05). Conclusion : Ultimately, balancing ability was improved in both of the groups after trunk exercises were performed. Although balancing ability was improved, elements of lower extremity dysfunction remained, such as unilateral foot-drop, toe-loss, and below-knee amputation.

• 대한물리의학회지
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• 제7권4호
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• pp.471-480
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• 2012

PURPOSE: The object of the present study is to investigate the effects of the insole supporting medial longitudinal arch while walking in spastic cerebral palsy with pes planus. METHODS: Ten spastic bilateral cerebral palsy children with pes planus participated in this study. The insole were custom-made for the individual child. Muscle activity was measured by surface EMGs attached on tibialis anterior (TA), gastrocnemius (GA), vastus medialis oblique (VMO), biceps femoris long head (BF). temporal-spatial parameters such as velocity, step length, stride length, stance time, toe angle were collected while the subjects walked on the GAITRite system. RESULTS: The results of the present study were summarized as follows: 1. Muscle activities in mean EMGs while walking: Left VMO, Right TA, Left BF and GA revealed significant reductions after applying insole. 2. Muscle activities in peak EMGs while walking: Left TA and BF demonstrated reductions significantly after applying insole. 3. There were improvements in temporal-spatial gait parameters with insole: velocity, both step length, Right stride length and Right toe angle were increased(p<.05). CONCLUSION: Therefore the current study demonstrated that insole supporting the medial longitudinal arch would be effective on gait of the spastic cerebral palsy with pes planus.

• 한국운동역학회지
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• 제26권2호
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• pp.161-166
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• 2016

Objective: The purpose of this study was to determine the knee and ankle joint kinematics and kinetics by comparing downhill walking with valley-shape combined slope walking. Method: Eighteen healthy men participated in this study. A three-dimensional motion capture system equipped with eight infrared cameras and a synchronized force plate, which was embedded in the sloped walkway, was used. Obtained kinematic and kinetic parameters were compared using paired two-tailed Student's t-tests at a significance level of 0.05. Results: The knee flexion angle after the mid-stance phase, the mean peak knee flexion angle in the early swing phase, and the ankle mean peak dorsiflexion angle were greater during downhill walking compared with valley-shape combined slope walking (p < 0.001). Both the mean peak vertical ground reaction force (GRF) in the early stance phase and late stance phase during downhill walking were smaller than those values during valley-shape combined slope walking. (p = 0.007 and p < 0.001, respectively). The mean peak anterior GRF, appearing right after toe-off during downhill walking, was also smaller than that of valley-shape combined slope walking (p = 0.002). The mean peak knee extension moment and ankle plantar flexion moment in late stance phase during downhill walking were significantly smaller than those of valley-shape combined slope walking (p = 0.002 and p = 0.015, respectively). Conclusion: These results suggest that gait strategy was modified during valley-shape combined slope walking when compared with continuous downhill walking in order to gain the propulsion for lifting the body up the incline for foot clearance.