• 대한의용생체공학회:의공학회지
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• 제21권2호
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• pp.213-218
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• 2000

Pressure distributions of the soft tissue are valuable for understanding and diagnosing the disease characteristics due to the mechanical loading. Our system measures dynamic pressure distributions in real-time under the general PC environment, and analyzes various foot disorders. Main features of the developed system are as follows: (1) With the resistive pressure sensor matrix of 40${\times}$40 cells, the data is sent to the PC with the maximum sampling rate of 40 frames/sec. (2) For each frame, contact area, pressure and force are analyzed by graphic forms. Thus, various biomechanical parameters are easily determined at specific areas of interests. (3) A certain stance phase can be chosen for the analysis from the continuous walking, and the detailed biomechanical analysis can be done according to an arbitrary line dividing anterior/posterior or medial/lateral plantar areas. (4) The center of pressure (COP) is calculated and traced from the pressure distribution data, and thus the movement of the COP is monitored in detail. A few experiments revealed that our system successfully measured the dynamic plantar distribution during normal walking.

• 대한기계학회논문집A
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• 제35권10호
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• pp.1237-1242
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• 2011

족저부의 압력 분포를 해석하기 위하여 인체에 근접한 족부 상세 해석용 모델을 개발하였다. 이 상세 해석용 모델은 족부의 단층촬영 영상(CT scan image)으로부터 밀도 차이에 따라서 골격부와 피부 및 피하조직을 각각 3D CAD 모델로 변환한 후에 결합하여 구성하였며, 근육과 뼈, 피부 모두를 반영한 3D 족부 유한요소해석 모델로 개발하였다. 개발된 3D 족부 유한요소모델에 대하여 NASTRAN의 접촉해석을 수행하여 족저압의 분포를 계산하였으며, 이러한 결과는 균일분포압력을 작용시키는 당뇨병 환자용 신발 설계의 기초 자료로 활용될 수 있다.

• 인터넷정보학회논문지
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• 제11권6호
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• pp.13-20
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• 2010

본 논문은 걸음걸이 분석 기반의 특징 추출과 NEWFM(Neural Network with Weighted Fuzzy Membership Functions)을 이용하여 건강한 사람의 족압(foot pressure)과 파킨슨병 환자의 족압으로부터 건강한 사람과 파킨슨병 환자를 분류하는 방안을 제시하고 있다. NEWFM에서 사용할 입력을 추출하기 위해서 첫 번째 단계에서는 PhysioBank에서 제공하는 족압 데이터와 시간에 따른 족압의 변화를 이용하여 각각 4개의 특징을 추출하였다. 두 번째 단계에서는 웨이블릿 변환(wavelet transform, WT)을 이용하여 이전 단계에서 추출한 8개의 특징으로부터 웨이블릿 계수를 추출하였다. 마지막 단계에서는 추출된 웨이블릿 계수들을 이용하여 통계적 기법인 주파수 분포와 주파수 변동량을 이용하여 40개의 입력을 추출하였다. NEWFM은 족압 데이터로부터 8개의 특징을 추출하여 건강한 사람과 파킨슨병 환자를 분류하였을 때 왼쪽 족압과 오른쪽 족압의 차를 이용한 특징과 시간에 따른 족압의 변화에 대한 차를 이용한 특징의 경우에 높은 정확도(accuracy)가 나타났다. 이러한 결과를 통하여 걸음걸이에 있어서 질질 끄는 특징을 보이는 파킨슨병 환자의 양쪽 족압의 차가 건강한 사람의 양쪽 족압의 차보다는 상대적으로 적다는 특징을 본 실험을 통해 확인할 수 있었다.

• 대한인간공학회지
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• 제26권2호
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• pp.157-165
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• 2007

The Work-Related Musculoskeletal Disorders (WMSDs) can be occurred by various factors such as repetition, forceful exertions and awkward postures. Especially, occurrences of the WMSDs on the waist and lower limb are reported in workplaces, demanded standing postures for a long time, in service and manufacturing industry. The static and standing postures without movement for a long time increase work loads to the lower limb and the waist. Accordingly, anti-fatigue mat or anti-fatigue insole is used as a preventing device of the WMSDs. However anti-fatigue mats are limited in space and movement. In this study, multi-elastic insoles are designed and shown the effects of the workload reduction for a long time under the standing work. The foot pressures and EMG (Electromyography) are measured at 0 hour and after 2 hours by 6 health students in their twenties. The 6 prototype insoles are designed with three elastic (Low, Medium and High). These insoles are compared with no insole (insole type 7) as control group. The EMG measurement was conducted to waist (erector spinae muscle), thigh (vastus lateralis muscle) and calf (gastrocnemius muscle). The foot pressure is analyzed by mean pressure value and the EMG analysis is investigated through MF (Median Frequency), MPF (Mean Power Frequency) and ZCR (Zero Crossing Rate). The results of the foot pressure show that the multi-elastic insoles had smaller foot pressure value than that of no-insole. Moreover, Insole 2 and Insole 3 have the smallest increasing rate in foot pressure. The EMG results show that the multi-elastic insoles had smaller EMG shift value than that of no-insole in 2 hour, and then shift value shows the smallest value in Insole 2. Therefore, this study presents that the multi-elastic insoles have reducing effects of the work load for a long time standing work in both side of foot pressure and EMG.

• Journal of Platform Technology
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• 제9권3호
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• pp.36-43
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• 2021

뇌졸중 질환은 전세계적으로 가장 중요한 사망원인 중 하나이며, 특히 고령자에게 장애의 원인이 되는 가장 중요한 질환이다. 뇌졸중 질환이 발생하면 사망 또는 심각한 장애를 유발하기 때문에, 적극적인 일차 예방과 전조증상의 빠른 발견이 매우 중요하다. 특히, 일상생활에서의 뇌졸중 전조증상 발병을 감지 및 정확히 예측하여 전문가의 신속한 진단을 유도할 수 있어야 한다. 최근까지의 연구에서는 뇌졸중 환자의 전조증상을 예측하는 방법론으로 CT(Computed Tomography)나 MRI(Magnetic Resonance Imaging)와 같은 영상 분석이 대부분이었으나, 이러한 접근에는 오랜 검사 시간과 높은 검사 비용 등에 대한 한계점을 가지고 있다. 본 논문에서는 고령자의 뇌졸중 질환 발병이 보행 시 족압(Foot Pressure)에 어떤 영향을 미치는지 임상 데이터를 이용해 실험하였다. 실험 결과, 보행 중에 뇌졸중 고령자와 일반 고령자 간에 12개의 셀에서 * p < .05 인 유의미한 차가 있음을 분석 및 검증하였다. 결과적으로 고령의 뇌졸중 환자와 일반 고령자의 일상생활의 보행 패턴에 유의미한 차이를 발견했다는 것에 그 의미가 크다고 할 수 있다.

• 한국운동역학회지
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• 제19권2호
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• pp.197-204
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• 2009

It bas been hypothesized that foot ulceration might be internally initiated. Current instruments which merely allow superficial estimate of plantar loading acting on the foot, severely limit the scope of many biomechanical/clinical studies on this issue. Recent studies have suggested that peak plantar pressure may be only 65% specific for the development of ulceration. These limitations are at least partially due to surface pressures not being representative of the complex mechanical stress developed inside the subcutaneous plantar soft-tissue, which are potentially more relevant for tissue breakdown. This study established a three-dimensional and nonlinear finite element model of a human foot complex with comprehensive skeletal and soft-tissue components capable of predicting both the external and internal stresses and deformations of the foot. The model was validated by experimental data of subject-specific plantar foot pressure measures. The stress analysis indicated the internal stresses doses were site-dependent and the observation found a change between 1.5 to 4.5 times the external stresses on the foot plantar surface. The results yielded insights into the internal loading conditions of the plantar soft-tissue, which is important in enhancing our knowledge on the causes of foot ulceration and related stress-induced tissue breakdown in diabetic foot.

• 대한인간공학회지
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• 제24권4호
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• pp.23-30
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• 2005

The mailman's shoes should be designed in due consideration of occupational features they spend most of times to walk. For that reason, the shoes required functions to reduce the foot fatigue and to protect body by dispersing the body weight to the whole foot. In this research, for the functional improvement of the insole, insoles are investigated and analyzed by biomechanics experimentation. Under the base of these experimental results, we develop insoles that can reduce the body load and muscular-skeletal disorder. The pressures are concentrated on the metatarsus and heel by the result of analyzing pressure distributions of the using shoes. Accordingly, we offer the prototype functional insole that is ranked from high pressure to low pressure on the base of a shock absorb function. This prototype functional insole is examined for statistical significance by pressure distribution areas. The experimental results show that pressure areas are dispersed to whole foot, for this reason, pressures of the metatarsus and heel are reduced. Results of this research can not only improve the function of insoles which is suitable for occupational features, but also be a base on constructing data bases for biomechanics gait insoles.

• 대한기계학회논문집A
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• 제36권8호
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• pp.913-920
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• 2012

단층촬영 영상정보를 이용하여 근육, 연부조직 및 골 구조 등을 포함한 발의 상세한 유한요소해석모델을 개발하여 보행과정을 모사하였고, 발과 직접 접촉하는 신발밑창 형상의 고려 여부에 따른 보행 중의 발바닥 압력의 변화를 비선형 접촉해석으로 계산하였다. 해석결과 직립 정지상태나 보행 중에는 공통으로 뒤꿈치가 지면에 닿을 때 압력집중이 가장 높았으며, 편평한 밑창보다 발바닥 곡면과 같은 밑창을 사용한 보행해석에서 뒤꿈치의 압력집중이 덜하고 접촉면이 더 넓었다. 이러한 보행모델 및 해석은 발바닥의 압력집중에 취약한 당뇨병 환자 전용 의료보조신발(압력을 넓게 분포시켜 집중의 강도를 낮출 수 있는) 개발의 수단으로 활용될 수 있음을 보였다.

• 한국운동역학회지
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• 제15권2호
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• pp.41-55
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• 2005

In this study, weight carrying pattern analysis and comparison method of four foot region were suggested. We used three types of club(driver, iron7, pitching wedge). This analysis method can compare between top class golfer and beginner. And the comparison data can be used to correct the swing pose of trainee. If motion analysis system, which can measure the swing speed and instantaneous acceleration at the point of hitting a ball, is combined with this plantar foot force analysis method, new design development of golf shoes to increase comfort and ball flight distance will be available. 1. Regional change of force acting, in address, is evenly distributed on both feet. In back swing top, 76% on right foot, 75% on left foot as impact, and 86% on left foot as finish. As regional force acting, in address, pros get high marks on rare and inside of right foot and rare and outside for amateurs. In back swing top, it is higher as fore and inside of left foot, pros as rare part of right foot and amateurs as forefoot. In impact, it is higher for pros and amateurs in outside and rare part of left foot and fore and inside of right foot. In finish, for both pros and amateurs, it is higher for outside and rare parts of left foot. 2. For each club, forces are evenly distributed on both feet in address. In back swing top, the shorter a club is, the higher impact on right foot and the higher finish distribution on left foot. For all the clubs used, in each region, pros get higher on rare and inside of right foot and as amateurs on rare and outside of left foot in address. In back swing top, for all clubs, pros get higher on rare and outside of right foot as fore and outside for amateurs. In impact acting, for all clubs, rare and outside of left foot get higher. In finish, force concentrates on rarefoot. 3. On both feet force, right foot forces of amateurs is higher than those of pros in back swing top. In impact and finish, pros get higher on left foot.

• 한국운동역학회지
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• 제19권1호
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• pp.13-25
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• 2009

Existing footwear biomechanics studies rely on simplified kinetics and kinematics, plantar pressure and muscle electromyography measurements. Because of the complexity of foot-shoe interface and individualized subject response with different footwear, consistent results regarding the biomechanical performance of footwear or footwear components can yet be achieved. The computational approach can be an efficient and economic alternative to study the biomechanical interactions of foot and footwear. Continuous advancement in numerical techniques as well as computer technology has made the finite element method a versatile and successful tool for biomechanics researchdue to its capability of modelling irregular geometrical structures, complex material properties, and complicated loading and boundary conditions. Finite element analysis offers asystematic and economic alternative in search of more in-depth biomechanical information such as the internal stress and strain distributions of foot and footwear structures. In this paper, the current establishments and applications of the computational approach for footwear design and evaluation are reviewed.