• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.728-733
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• 2001

The subject of this paper is to perform the basic research to make design guide as finding out the structural characteristics of polypropylene Ankle Foot Orthosis(AFO) for hemiplegics. Target shape of AFO is a solid standard type. In this study we measure ridity as dorsiflexion and thicknesses of AFO with three types of ankle widths and analyze correlation between rigidity and ankle widths, thicknesses. As a result, the rigidity characteristic is specified complex effect of ankle widths and thicknesses.

• 대한통합의학회지
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• 제4권4호
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• pp.33-39
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• 2016

Purpose : The aim of this study was to investigate the effects of plastic ankle foot orthosis on adult post-stroke hemiplegic patients walking ability and balance. Method : The searched for the case controlled clinical trials about the effects of plastic ankle foot orthosis(pAFO) for walking ability and balance using quantitative gait analysis in adult post-stroke patients. Ten trials were selected from Riss4U databases published until June 2016 in Korea. The selected trials contained a control group with pre-test and post-test design, measured walking ability and balance as a dependent variable. Result : The selected ten trials involved a total of 180 patients. The walking speed, cadence, the portion of double limb supporting, stride length on affected side were improved by plastic ankle foot orthosis. Conclusion : The plastic ankle foot orthosis has some evidence to improve the walking ability and balance in post-stroke hemiplegic patients.

• 대한인간공학회지
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• 제30권2호
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• pp.291-296
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• 2011

This study was designed to investigate the effects of an ankle foot orthosis(AFO) with variable ankle joint angles on balance performance in healthy adults. Eighteen healthy adults were recruited in this repeated measures design with subjects as their own controls. An AFO with four kinds of ankle joint angles(-5, 0, 5, and 10 degree) were used and balance performance was measured during single limb standing. Three trials were obtained and then averaged for data analysis. Foot pressure was measured using an F-scan system and muscle activity was measured using an MP150 system. There were significant differences in balance performance with ankle joint angles. An AFO with -5 degrees was associated with significant increases in postural sway(anterior-posterior), and in muscle activity for the medial gastrocnemius and tibialis anterior compared with other degrees of angle. Findings of this study show that angles of an AFO are related to balance performance and a joint angle of 10 degree is effective for promoting joint stability and postural control. This information can be used by clinicians to prescribe AFOs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.193-195
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• 2006

In this study, we developed an active controlled ankle-foot orthosis(AAFO) which can control the dorsiflexion/plantarflexion of the ankle joint during gait to prevent foot drop and toe drag for paralysis patients. To prevent dropping foot after heel strike, ankle joint was actively controlled to minimize forefoot collision with the ground. It was also controlled to provide toe clearance and to help push-off during late stance. The 3D gait analysis was performed on two healthy subjects equipped with the developed AAFO to compare with the normal gait and the conventional AFO gait. In the developed AAFO gait, differently from the conventional AFO gait, significant push-off was observed during pre-swing and the maximum flexion moment during pre-swing phase was similar to that of normal gait. A remarkable dorsiflexion also occurred during initial swing. These results indicated that the developed AAFO could have certain clinical benefits to prevent foot drop for paralysis patients, compared to conventional AFOs.

• 한국전문물리치료학회지
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• 제22권2호
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• pp.52-58
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• 2015

Balance control deficits have been indicated to be a primary problem among cerebral palsy (CP) patients. Fabric ankle foot orthosis (AFO) can allow more efficient balance control by facilitating proprioception. The purpose of this study was to investigate the immediate effect of fabric AFO on balance, compared to a barefoot condition in children with unilateral CP. Twelve children with unilateral CP participated in this study. Their balance ability was evaluated using pediatric balance scale and bubble test. Both pediatric balance scale and bubble test showed significant improvement with the use of the fabirc AFO (p<.05). The fabric AFO could improve functional balance ability, and promote better balance among children with unilateral CP. We demonstrated that fabric AFO contributed to improving balance among children with unilateral CP, classified as Gross Motor Function Classification System level I and II. Consequently, fabric AFO might be an assistive device leading to the improvement of balance instead of the typical AFOs.

• 대한기계학회논문집A
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• 제26권1호
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• pp.7-14
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• 2002

In this study, a stress analysis is made fur an ankle foot orthosis (AFO) in the view point of structural stability. The investigated AFO is a solid and standard type. To analyze the stress distribution on the neck of AFO, the maximum AFO angular translation data is obtained by gait analysis. The material test of polypropylene is made to obtain the mechanical properties of AFO. The maximum dorsiflexion appears at the midstance in the gait analysis. The experimental angular translation at the top of AFO is about 10.3$^{\circ}$ at mid stance. Three models of AFO with different width of neck are made and analyzed with ABAQUS 6.1. The stress levels and distributions of 3 different width(W$_1$, W$_2$=0.85W$_1$, W$_3$=0.60W$_1$) AFO are investigated. As a result, the standard type(W$_1$) appears to the maximum stresses at the medial edge of cutout area surrounding ankle joint. The maximum stresses of the narrower type(W$_2$) are occured on medial edge and center of ankle. The narrowest type(W$_3$) appears to the maximum stresses at center of ankle. The maximum stresses become smaller as ankle width of AFO is narrower.

• 한국정밀공학회지
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• 제25권3호
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• pp.165-175
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• 2008

An ankle-foot orthosis(AFO) is a brace for persons with gait disabilities to support or replace the function of ankle joint. Ankle-foot orthoses(AFO's) are usually prescribed to alleviate the drop-foot by constraining the excessive plantar flexion. The shape and the strength of the AFO are often based on 'trial and error' due to a lack of knowledge of the stress distribution in the AFO. In this study, an improved stress-freezing method was proposed to measure the stress distribution characteristics in the AFO. As a result, a photoelastic material with low freezing temperature was developed to measure the stresses under a person's direct contact loading condition. The three-dimensional stress-1rozen photoelastic models of AFO's for five stages of stance phase such as heel contact, foot flat, mid stance, heel off, and toe off were produced. The results of photoelastic analysis revealed that the stresses developed in the AFO were varied considerably from tensile to compressive or vice versa, during walking. At the posterior part of ankle joint in the AFO, the maximum compressive stress of 1.81MPa was observed in the mid stance, and the maximum tensile stress of 0.74MPa was observed during heel contact. The overall stress levels in the AFO's were low in the toe off phase. The results suggested that the posterior part of ankle joint might be the most fragile part in the AFO.

• 대한물리의학회지
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• 제15권1호
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• pp.1-9
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• 2020

PURPOSE: Many patients with stroke have difficulties in walking with foot-drop. Various types of ankle-foot orthoses (AFOs) have been developed, but their weight needs to be reduced with the assistance of the ankle dorsiflexor. Therefore, an elastic AFO (E-AFO) was devised that not only improves the stability and flexibility of the ankle but also assists with ankle dorsiflexion while walking. This study examined the effects of an E-AFO, on the walking patterns of foot-drop patients with stroke. METHODS: Fourteen patients walked with and without an E-AFO, and the gait parameters were assessed using the GAITRite system. The spatiotemporal data on the gait patterns of stroke patients with foot-drop were compared using paired t-tests; the level of statistical significance was set to α<.05. RESULTS: No significant differences were observed in the velocity (p=.066) and affecte+d step length (p=.980), but the affected and less-affected stance (p=.022, p=.002) and swing time (p=.012, p=.005) were significantly different. The E-AFO produced a significant difference in the less-affected step length (p=.032). CONCLUSION: The E-AFO has a significant effect on the walking patterns of individuals with foot-drop and stroke. The E-AFO could be a useful assistive device for gait training in stroke patients.

• The Journal of Korean Physical Therapy
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• 제17권1호
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• pp.96-107
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• 2005

Objective: The purpose of this study were to investigate the standing balance, dynamic activity in hemiplegic patients according to the types of ankle-foot orthosis(AFO) and to determine the most effective type of AFO for gait training. Method: A prospective study was performed for 16 patients with hemiplegia who was able to walk independently. Static balance and dynamic activity were compared in two condition : 1) barefoot and SPAFO, 2) barefoot and HPAFO. Static balance and dynamic activity characteristics were evaluated by Active Balance while they were standing with in two condition AFO and barefoot. Results: There were significant difference in standing balance between barefoot and wearing SPAFO and HPAFO(p<0.05). There were significant difference in dynamic activity balance between barefoot and wearing SPAFO and HPAFO(p<0.05). There were significant difference in gait speed between barefoot and wearing SPAFO and HPAFO(p<0.05). Conclusion: This study showed that wearing SPAFO and HPAFO gave fair amount of improvement to balance and gait ability of hemiplegic patients.

• 대한중풍순환신경학회지
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• 제14권1호
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• pp.40-48
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• 2013

■ Objectives This study was designed to investigate the effects of an ankle foot orthosis(AFO) on gait of two hemiparetic stroke patients with foot drop. ■ Methods Gait of two hemiparetic stroke patients were analyzed during walking on the treadmill without or with AFO application. The spatiotemporal and center of pressure(CoP) intersection parameters of gait analysis were measured using a treadmill gait analysis system. ■ Results The AFO had positive effects on hemiparetic gait parameters; increasing cadence, increasing step length, decreasing step time, stride time, and lateral symmetry. ■ Conclusion Hemiparetic gait was improved by ankle foot orthosis.