• 한국운동역학회지
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• 제16권2호
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• pp.193-205
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• 2006

This study was to analysis the kinematic and kinetic differences between new walking shoe(NWS : RYN) and general walking shoe(GWS). The subjects for this study were 10 male adults who had the walking pattern of rearfoot shrike with normal foot. The movement of one lower leg was measured using plantar pressure and Vicon Motion Analysis Program(6 MX13 and 2 MX40 cameras : 100 f / s) while the subjects walked at the velocity(1.5m/s. on 2m).. The results of this study was as follows : 1. The NWS was better than the GWS that caused injuries such as adduction, abduction and pronation are reduced While walking on a perpendicular surface, the landing angle and the knees angles were extensive which makes walking more safe which reduces anxiety and uneasiness. 2. The bottom of the NWS were now made into a more circular arch which supports the weight of the body and reduces the irregular angles when wearing GWS. This arch made the supporting area more wide which made the upholding the trunk of the body more effective. The whole bottom of the foot that supports the weight is more flexible in addition, increases the safeness of walking patterns and the momentum of the body. 3. The moment the heel of the foot of the NWS touch the ground, the range of the pressure were partially notable and the range of the pressure on the upper part of the thigh were dispersed The injuries that occurred while walking. primary factors when a shock related injuries are reduced Judgements of the impacts of the knees and the spinal column dispersing could be made.

• 한국운동역학회지
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• 제21권4호
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• pp.487-494
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• 2011

The purpose of this study was to evaluate the effects of metatarsal pad (MP) compared with barefoot and MP with using different insoles on gait. 15 healthy females who had no history of injury in the lower extremity with an average age of 22.7 year(SD=1.35), height of 160 cm(SD=3.4), weight of 48.8 kg(SD=5.52) and average foot size of 232.5 mm(SD=6.8) participated in this study as the subjects. The subjects walked on a treadmill under four different experimental conditions: 1) walking with barefoot, 2) walking wearing MP 3) walking wearing a soft insole with MP(SIMP), 4) walking wearing a rigid insole with MP(HIMP). During walking, foot pressure data such as force, contacting area, peak pressure, and mean pressure was collected using Pedar-X System(Novel Gmbh, Germany) and EMG activity of lower limb muscles such as tibialis anterior(TA), lateral gastrocnemius(LG), rectus femoris(RF), and musculus biceps femoris(MBF) was gathered using Delsys EMG Work System(Delsys, USA). Collected data was then analyzed using paired t-test in order to investigate the effects of each of experimental conditions. As a result of the analysis, when MP and HIMP were equipped, overall contacting area was increased while the force, peak pressure and the mean pressure were decreased. Especially, when the SIMP was equipped, every data were significantly decreased. In case of EMG, wearing MP, SIMP and HIMP made three muscles(TA, LG, RF)'s activity decrease. A result of the analysis will be able to apply for manufacturing functional shoes, diabetes shoes, senior shoes and lower extremity orthosis. Significance of the study due to a metatarsal pad and the insole is to analyze the changes in muscle strength.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4689-4696
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• 2015

본 연구에서는 F사가 맨발 보행 효과에서 착안하여 최적의 착화감과 압력 분산의 효과를 트레킹화에 접목시키기 위해 고안한 3D Bootie 공법을 적용시킨 트레킹화에 대한 생체역학적 분석을 수행하였다. 이를 위해 비교군으로써 M사, K사의 일반 트레킹화에 대하여, 신체 건강한 20대 남성 13명을 대상으로 보행 시 족저압력분포, 하지 근 활성도, 지면반발력을 측정하여 분석하였다. 연구 결과, F사의 트레킹화는 족저압력 분포에서 넓은 접촉 면적으로 인하여 최대 힘과 최대 압력의 감소를 야기했으며, 보행 시 발의 부하를 경감시켰다. 근 활성도 측면에서는 맨발 보행의 효과와 동일하게 작용했다. 지면반발력에서는 효과적으로 충격력을 흡수하여, 말기입각기 때 더욱 효율적인 보행이 가능하였다. 결과적으로 F사의 트레킹화는 맨발 보행의 장점을 이용한 3D Bootie 공법을 적용함으로써 넓은 접촉 면적으로 인해 보행 시 발생하는 발의 부하를 감소시킬 것으로 사료된다.

• 대한의용생체공학회:의공학회지
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• 제38권1호
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• pp.9-15
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• 2017

Recently, flexible cages have been introduced in an attempt to absorb and reduce the abnormal load transfer along the anterior parts of the spine. They are designed to be used with the pedicle screw systems to allow some mobility at the index level while containing ROM at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the flexible cage when combined with pedicle screws with flexible rods. The post-operated models were constructed by modifying the L4-5 of a previously-validated 3-D FE model of the intact lumbar spine (L2-S1): (1) Type 1, flexible cage only; (2) Type 2, pedicle screws with flexible rods; (3) Type 3, interbody fusion cage plus pedicle screws with rigid rods; (4) Type 4, interbody fusion cage plus Type 2; (5) Type 5, Type 1 plus Type 2. Flexion/extension of 10 Nm with a compressive follower load of 400N was applied. As compared to the Type 3 (62~65%) and Type 4 (59~62%), Type 5 (53~55%) was able to limit the motion at the operated level effectively, despite moderate reduction at the adjacent level. It was also able to shift the load back to the anterior portions of the spine thus relieving excessively high posterior load transfer and to reduce stress on the endplate by absorbing the load with its flexible shape design features. The likelihood of component failure of flexble cage remained less than 30% regardless of loading conditions when combined with pedicle screws with flexible rods. Our study demonstrated that flexible cages when combined with posterior dynamic system may help reduce subsidence of cage and degeneration process at the adjacent levels while effectively providing stability at the operated level.

• 한국운동역학회지
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• 제19권1호
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• pp.149-157
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• 2009

본 연구의 목적은 한국의 대표적인 배드민턴화(A Type)와 외국 배드민턴 브랜드제품(B Type)의 생체역학적인 변인들을 비교함으로서 한국제품의 착화감과 기능을 향상시켜 세계적인 수준의 배드민턴화 개발에 일조하는데 목적을 두었다. 분석변인들로는 동작 간 신발 안에서 발의 상대적인 움직임, 지면반력과 압력분포, 아웃솔의 마찰력등을 분석하였다. 또한 17명의 피험자를 통한 주관적인 착화감과 기능에 관련된 주관적인 실험이 실시되었다. A Type 배드민턴화의 경우 높은 뒤꿈치의 위치와 밋밋한 뒷굽의 형태로 신발 안에서 뒤꿈치를 잘 잡아주지 못하는 것으로 나타났다. 따라서 A Type 배드민턴화가 약 40%이상 발이 신발 안에서의 미끄러짐 현상이 일어났으며 충격력의 형태나 최대 압력분포도 높게 나타났다. Type A 신발의 경우 Type B와 같이 자연스러운 굴곡이 발의 볼쪽에서 일어나지 않고 전족부근에서 일어났다. 요약을 하면, 두 신발 간에 몇몇 차이점들이 발견되었고 A Type 배드민턴화의 기능을 향상하기 위해서 보완가능 요인들이 제시되었다.

• 대한의용생체공학회:의공학회지
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• 제43권5호
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• pp.308-318
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• 2022

The purpose of this study is to evaluate the biomechanical properties of fractured adjacent soft tissue during closed reduction after forearm fracture using the finite element method. To accomplish this, a finite element (FE) model of the forearm including soft tissue was constructed, and the material properties reported in previous studies were implemented. Based on this, nine finite element models with different fracture types and fracture positions, which are the main parameters, were subjected to finite element analysis under the same load and boundary conditions. The load condition simulated the traction of increasing the fracture site spacing from 0.4 mm to 1.6 mm at intervals of 0.4 mm at the distal end of the radioulnar bone. Through the finite element analysis, the fracture type, fracture location, and displacement were compared and analyzed for the fracture site spacing of the fractured portion and the maximum equivalent stress of the soft tissues adjacent to the fracture(interosseous membrane, muscle, fat, and skin). The results of this study are as follows. The effect of the major parameters on the fracture site spacing of the fractured part is negligible. Also, from the displacement of 1.2 mm, the maximum equivalent stress of the interosseous membrane and muscle adjacent to the fractured bone exceeds the ultimate tensile strength of the material. In addition, it was confirmed that the maximum equivalent stresses of soft tissues(fat, skin) were different in size but similar in trend. As a result, this study was able to numerically confirm the damage to the adjacent soft tissue due to the fracture site spacing during closed reduction of forearm fracture.

• 한국임상수의학회지
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• 제40권2호
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• pp.93-103
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• 2023

The tendon is a dense connective tissue that connects muscle to bone and plays an essential role in joint motion. The injured tendon heals slowly owing to its low cellularity and vascularity. This study aimed to evaluate and compare the effects of regenerative injection therapy (RIT), 20 % dextrose prolotherapy (DP), and platelet-rich plasma (PRP) injections that can promote tendon healing. Twenty-one New Zealand white rabbits were divided into the control, DP, and PRP treatment groups. The superficial digital flexor tendon (SDFT) of the right hindlimb of each rabbit was used. A round defect of 2 mm was induced. Approximately 0.2 mL of 20% dextrose and autologous PRP were injected into the proximal and distal ends of the SDFT mass. Radiographic and ultrasonographic examination and cross-sectional area (CSA) calculations were performed pre-operatively and at 2, 4, and 8 weeks. The SDFT of both limbs was transected for biomechanical and histomorphometric evaluations. The SDFT of the left limb was transected for intact control. Semi-quantitative analysis was performed to evaluate the histomorphometric properties. Additional analysis was performed using H&E, Masson's trichrome, and immunohistochemical staining. The biomechanical evaluation showed that the treatment groups had higher tensile strength compared to the defect control group, while the PRP group had higher tensile strength than the DP group. On histological examination, the treatment groups appeared to be relatively closer to the remodeling phase of the healing process than the defect control group; the characteristics of the PRP group were closer to the remodeling phase than those of the DP group. The ultrasonographic examination showed different tendencies. Increased values in the CSA were observed during the early period in the treatment groups. This study suggests that PRP and DP can promote the healing of tendon injury, and these effects were superior with PRP than that with DP.

• 대한인간공학회지
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• 제35권6호
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• pp.503-517
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• 2016

Objective: The aim of this study was to evaluate the effectiveness of 3 dimensional contoured pillow through analyzing contact pressure and to suggest its design guidelines through analyzing the posture of head and neck area. Background: The quality of sleep is a very important factor closely related with human's health. To improve the quality of sleep, the verification of design factors affecting the posture of the head and neck is needed, and a pillow design that can induce proper posture is required. Method: This study measured the contact pressures of the two reference groups (bead and cotton pillows) as a method to evaluate the design effectiveness of the contoured pillow. This study proposed 3-dimensional design guidelines by drawing anthropometry (head length) affecting cervical curvature angle (CCA) through the measurement of the participants' cervical curvature angles. Results: In the design effectiveness evaluation, the contact pressure of cervical region was higher than that of a reference group (cotton pillow), and contract area increased, and contract pressure decreased in the shape distributing the occipital region's body pressure. This study proposed pillow's cervical supporting height by percentile of a head length [head length (%tile) (cervical supporting height) affecting the posture of the head and neck: 14.6cm (5%tile) (6.2cm), 15.5cm (25%tile) (6.7cm), 16.4cm (50%tile) (7.1cm), and 19.3cm (75%tile) (8.9cm)]. Conclusion: This study confirmed the contoured pillow's design effectiveness maintaining cervical angle comfortable to sleep with the shape supporting the cervical vertebrae and by reducing the contact load of the occipital region. Also, this study proposed pillow design guidelines based on the 3-dimensional contoured pillow design effectiveness, through which the study laid the foundation for pillow design in a systematic method. Application: The results of this study are expected to be utilized as the basis data by which the optimum pillow type and pillow design according to main percentile can be standardized.

• 구강회복응용과학지
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• 제24권1호
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• pp.41-56
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• 2008

상용 임플란트의 표면을 개질하기 위해 물리적, 화학적 방법을 이용한 새로운 표면이 증가하고 있으며 이에 대한 골반응도 다를 것으로 예상할 수 있지만 대부분의 연구는 단순히 기계절삭형 임플란트와의 비교만을 하고 있다. 본 연구에서는 4종의 다른 개질된 표면을 가진 상용 임플란트를 가토의 경골에 식립한 후 생역학적, 조직형태학적으로 비교하였다. 연구 결과, 모든 임플란트는 6주 후 안정적인 골유착을 이루고 있었으며 4종의 표면개질의 차이에 의한 공진주파수 및 조직형태학적 골반응의 차이는 없었으며 표면개질을 비교하기 위해 피질골 하방으로 증식한 골을 비교하는 것이 유용하였다. 생역학적, 조직형태학적 골반응에 비해 미세단층촬영(micro-CT)를 이용하는 비교법은 유용성과 정확도가 낮은 것으로 나타났다.

• 한국산업보건학회지
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• 제18권3호
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• pp.239-247
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• 2008

Low back disorders (LBDs) have been the most common musculoskeletal problem in Korean workplaces. It affects many workers, and is associated with high costs to many companies as well as the individual, which can negatively influence even the quality of life of workers. The _evaluation of low back disorder risk associated with manual materials handling tasks can be performed using variety of ergonomic assessment tools such as National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (NLE), the Washington Administrative Code 296-62-0517 (WAC), the Snook Tables etc. But most of these tools provide limited information for choosing the most appropriate assessment method for a particular job and in finding out advantage and disadvantage of the methods, and few have been assessed for their predictive ability. The focus of this study was to _evaluate spinal loads in real time with lifting and pulling heavy cow leathers in variety of postures. Data for estimating mean trunk motions were collected as employees did their work at the job site, using the Lumbar Motion Monitor. Eight employees (2 males, 6 females) were selected in this study, in which the load weight and the vertical start and destination heights of the activity remained constant throughout the task. Variance components (three dimensional spaces) of mean trunk kinematic measures were estimated in a hierarchical design. They were used to compute velocity and acceleration of multiple employees performing the same task and to repetitive movements within a task. Therefore, a results of this study could be used as a quantitative, objective measure to design the workplace so that the risk of occupationally related low back disorder should be minimized.