• Physical Therapy Korea
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• v.27 no.4
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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.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.81-94
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• 2007

The purpose of this study was to critically review biomechanical studies on foot orthoses (FO) in normal and diseased foot and provide beneficial information obtained from researches until now and future researching focus. The search was performed by Medline and Embase database including studies published in English from January 1980 to April 2007. The searching terms were foot orthoses, foot orthotics, insoles and shoe insert. 57 studies including 54 journal articles and 3 abstracts were finally selected under the conditions of having clinical trials, FO, control condition, movement, scientific measuring system. The reviewed studies were divided into 10 categories according to subject characteristics; healthy normal, excessive pronation or flexible flat foot, rheumatoid arthritis, diabetes, medial knee osteoarthritis, forefoot varus, plantar fasciitis, patellofemoral syndrome, cavus foot and finite element model. In summary, first, soft and semirigid FOs with some degree of cushioning showed much higher comfort and efficacy than rigid FO. Second, no big differences between prefabricated and custom FO were shown. Third, the full length's FO was preferable to the half length's FO or simple arch supports. Fourth, the wearing of FO combining medial arch supports and metatarsal dome made positive roles to enhance comfort and functionality and redistribute plantar pressure under the foot. Fifth, for patients with knee-related diseases lateral wedges were preferable. Sixth, measuring systems were properly applied according to the types of foot diseases.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.47-52
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• 2011

The functional loot orthoses, when wearing shoes, are in the direct contact with bottom of foots to improve and recover the correctness of abnormal lower limb musculoskeletal imbalance and the primary role of foot and also, it can act to keep the balance and weight of body and support the weakened region, so that it is very helpful to keep body balance for the standing position. In this paper, it was researched that foot orthoses which is accommodable for the function of impact absorption including the gait stability affect on the balanced performances of body in according to the formation and the material of foot part. Taking into account the balanced performances by using the sway velocity, the estimation and comparison of the effects on the balanced performances by each formation and material for foot orthoses was evaluated into significant values(p<0.006) in only the eye-opening posture with Firm state, In this posture, the static process performed by each foot formation reveals in order of normal foot(p<0.010), flat foot(p<0.000) and hollow foot(p<0.003) and then, on the base of each formation of foot part, the result that analyze the effects of the materials of foot orthoses on the balance performance appeared showing that soft materials is more effective on the normal foot and, on the other hand, rigid materials is more effective in balancing on flat foot and hollow foot.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.888-892
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• 2003

This study was tested for the bending stress analysis of Experimental stress analysis on various ankle foot orthoses(AFOs) was fulfilled. Stress was measured by Strain gages which were attached on 8 region in AFOs Results revealed that the peak compressive/tensile stress in the orthoses occured in the lateral region of neck. The Stress Analysis system was made by the electronic oscilloscope, strain gage sensors, amplifier, A/D converter, PC with C program It will be able to using the important data in splint design. Selected AFOs were some different materials but all have same shape except one type(orthosis with joint). C program Is used for managing data. Thus lateral side of the neck region is failed easily.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.349-350
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• 2012

본 연구에서는 경첩 발목 보조기(Hinged Ankle Foot Orthoses, HAFO)의 착용이 경직성 뇌성마비 아동의 보행 시 신체 질량 중심점(Center of Mass, COM)에 미치는 영향을 알아보고자 한다. 실험은 보조 기구의 사용 없이 독립적인 보행이 가능한 경직성 뇌성마비 아동(하지마비 아동 8명, 편마비 아동 5명) 13명이 참여하였다. 34개의 적외선 반사 마커를 신체에 직접 부착한 뒤, 6대의 동작분석 카메라로 맨발 보행과 HAFO착용 보행을 각 5회 촬영하였다. 전-후방, 내-외측, 수직 방향으로의 COM의 이동과 COM 속도를 계산하여 HAFO착용 전 후를 대응표본 T검정으로 분석하였다. HAFO 착용은 양하지 마비 아동 그룹은 COM의 전방 이동이 유의하게 증가하였고(p<0.01), COM 속도는 내-외측과 수직 방향에서 유의하게 증가하였다(p<0.01). 반면 편마비 아동 그룹은 COM 이동과 속도가 모든 방향에서 유의하게 증가하였다(p<0.01). 따라서 HAFO는 뇌성마비 아동의 보행 기능을 개선시킨다고 할 수 있다.

• The Journal of Korean Physical Therapy
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• v.16 no.3
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• pp.161-175
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• 2004

The purpose of this study was to determine the effect of HPAFO(Hinged Plastic Ankle Foot orthosis) and SPAFO(Solid Plastic Ankle Foot Orthosis) on standing balance and step moving in hemiplegia patients. Twenty hemiplegic patients were either inpatient or outpatient at the Rehabilitation medicine, MokPo J General Hospital and JeonJu J Medical Center from July 15, 2002 to September 15, 2002. Patients were able to ambulate independently for at least 10 meters and to stand independently for at least 10 minutes with balance measurement tool. The static balance and dynamic activity measurement was determined by SAKAI active balancer(Japan) with wearing HPAFO and wearing SPAFO. The static balance and dynamic activity analysis was analyzed by independent t-test. The results were as follows: 1. There were no significant difference in body weight bearing percent between wearing HPAFO and wearing SPAFO(p>0.05). 2. There were significant difference in whole path length between wearing HPAFO and wearing SPAFO(p<0.05). 3. There were significant difference in Effective Value Area between wearing HPAFO and wearing SPAFO(p>0.001). 4. There were significant difference in repeated functional time between wearing HPAFO and wearing SPAFO(p>0.001). 5. There were significant difference in cadence between wearing HPAFO and wearing SPAFO(p>0.001). The result of this study showed that wearing HPAFO and wearing SPAFO gave fair amount of improvement to static standing balance and dynamic movement ability of hemiplegic patients. The comparison result showed significant differences in between HPAFO and SPAHFO. The result of this study had a general limitation due to the restricted number of cases. The future study needs more detailed research and comparison with various variance between these two orthoses.

• Physical Therapy Korea
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• v.18 no.3
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• pp.16-25
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• 2011

This study aimed to evaluate factors related to the ability of ambulatory patients with cerebral palsy (CP) to walk over vertical and horizontal obstacles. Twenty patients with spastic CP who were able to walk independently for at least 10 m with or without walking devices were recruited for the study. Participants were required to walk over small obstacles (1, 4, and 8 cm in height or width; total of 6 conditions). A 'fail' was recorded when either the lower limbs or the walking device contacted the obstacle. Linear regression analyses were used to determine the effects of age, sex, walking devices, eyeglasses, subtype (hemiplegia or diplegia), ankle foot orthoses, functional level, and score of body mass index on the ability of obstacle crossing. Fifteen participants (75%) failed to adequately clear the foot or walking device over obstacles in at least 1 condition. The chance of failure in crossing vertical obstacle was affected by the use of ankle foot orthoses, eyeglasses, gender, and CP subtype (p<.05). The failure rate crossing horizontal obstacle was affected by CP subtype. These findings suggest that rehabilitation procedures should (1) consider the clinical characteristics of patients in order to prepare them to be more independent while performing daily activities, and (2) incorporate environmental conditions that patients encounter at home and in the community.

• Journal of Korean Foot and Ankle Society
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• v.20 no.2
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• pp.55-61
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• 2016

The cavus foot is a deformity characterized by an elevated medial longitudinal arch and a hindfoot varus with plantarflexed 1st ray. The etiology of cavus foot is usually related to neuromuscular disease or idiopathic cause. Thorough clinical and radiographic evaluation is required for differentiating etiology of the cavus. Most cases of cavus foot are stable and slowly progressive deformities which can initially be managed with conservative treatment including orthoses and physical therapies. Determining whether the deformity is flexible or rigid, the apex of the deformity and any muscle imbalances in foot and ankle is important for achievement of an adequately balanced plantigrade foot. Treatment should include systematic preoperative planning for selection of appropriate procedures for maintaining a functional and flexible foot with combinations of soft-tissue release, osteotomy, tendon transfer, and arthrodesis.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.3
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.260-263
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• 2005

In this study, we analyzed the plantar shear stress and pressure of diabetic foot patients during walking by using in-shoe local shear force and plantar pressure measurement system. Twelve normal subjects and three diabetic foot patients with diabetic neuropathy in lateral heel were participated in this study. The center of pressure in diabetic foot patients moved more medially and directed toward 1st, 2nd metatarsal heads and hallux during late stance period, making pressure at the medial heel and 2nd metatarsal head significantly higher than in the normal. Shear stress at the heel were changed significantly in early stance and the magnitude of shear stresses in each metatarsal head were also changed. Further studies would be very helpful to design foot orthoses in patients with diabetic neuropathy or other diseases.