• Clinics in Shoulder and Elbow
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• 제23권1호
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• pp.27-30
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• 2020

Osborne-Cotterill lesion is an osteochondral fracture located in the posterolateral margin of the humeral capitellum, which may be associated with a defect of the radial head after an elbow dislocation. This lesion causes instability by affecting the lateral ulnar collateral ligament over its capitellar insertion, which is associated with a residual capsular laxity, thereby leading to poor coverage of the radial head, and hence resulting in frequent dislocations. We present a 54-year-old patient, a physician who underwent trauma of the left elbow after falling from a bike and suffered a posterior dislocation fracture of the elbow. The patient subsequently presented episodes of instability, and additional work-up studies diagnosed the occurrence of Osborne-Cotterill lesion. An open reduction and internal fixation of the bony lesion was performed, with reinsertion of the lateral ligamentous complex. Three months after surgery, the patient was asymptomatic, having a flexion of 130° and extension of 0°, and resumed his daily activities without any limitation. Currently, the patient remains asymptomatic 2 years after the procedure. Elbow instability includes a large spectrum of pathological conditions that affect the biomechanics of the joint. The Osborne-Cotterill lesion is one among these conditions. It is a pathology that is often forgotten and easily overlooked. Undoubtedly, this lesion requires surgical intervention.

• 자원환경지질
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• 제33권1호
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• pp.51-59
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• 2000

As a part of natural hazard assessment, regional slope stability analysis was conducted using Geoscientific Information System (GIS) in the northern area of Chungju Lake. Selected factors which affect the slope stability in the study area were lithology, soil, density of lineament, groundwater level, dip of slope, aspect of slope, and geological engineering properties. Geological structural domains were determined by collected data of joint orientation from about 200 sites in order to produce a slope instability map. Potential type of failure and its direction could be expected through the domains. And a slope instability map was produced, comparing the representative orientations of the domains with the orientations of the slopes which were made through TIN module in ARC/INFO. Under the consideration of environmental geological characteristics of the study area, rating and weighting of each factor of slope stability analysis were decided and spatial analysis of regional slope stability was couducted through overlaying technique of GIS. The result of areal distribution of slope stability showed that the most unstable area was the area between Mt. Pudae and Mt. Jubong, and the northern area of the railway station, Samtan.

• 한국공간구조학회논문집
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• 제14권3호
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• pp.47-56
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• 2014

This paper investigates the characteristics of unstable behaviour and critical buckling load by joint rigidity of framed large spatial structures which are sensitive to initial conditions. To distinguish the stable from the unstable, a singular point on equilibrium path and a critical buckling level are computed by the eigenvalues and determinants of the tangential stiffness matrix. For the case study, a two-free node example and a folded plate typed long span example with 325 nodes are adopted, and these adopted examples' nonlinear analysis and unstable characteristics are analyzed. The numerical results in the case of the two-free node example indicate that as the influence of snap-through is bigger; that of bifurcation buckling is lower than that of the joint rigidity as the influence of snap-through is lower. Besides, when the rigidity decreases, the critical buckling load ratio increases. These results are similar to those of the folded-typed long span example. When the buckling load ratio is 0.6 or less, the rigidity greatly increases.

• 대한족부족관절학회지
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• 제22권1호
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• pp.8-15
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• 2018

Ankle osteoarthritis is a debilitating condition that causes severe pain associated with functional impairment and decreased activity. Ankle osteoarthritis, unlike that of the knee or hip joint, is rare in primary arthritis. Most cases are traumatic arthritis that occur after ankle sprain or fractures or chronic ankle instability. Although ankle fusion has been regarded as the standard treatment of ankle osteoarthritis in the past, total ankle arthroplasty (TAA) is increasing due to the development of the implant design and surgical techniques. TAA is biomechanically superior to ankle fusion by preserving the movement of the ankle joint. In particular, it is functionally superior to ankle fusion because it enables normal joint motion during gait. In addition, there is an advantage of preserving the movement of the hindfoot and reducing the abnormal stress applied to the adjacent joints after ankle fusion to prevent the occurrence of long-term adjacent joint arthritis. Although the short-term and mid-term results of TAA have been reported to be excellent, long-term follow-up has a relatively low survival rate and high complication rate compared to total knee or hip arthroplasty. Therefore, continuous and further research is needed.

• 대한인간공학회지
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• 제32권3호
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• pp.245-252
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• 2013

Objective: This paper analyzes the changes on stride parameters, joint angles, and trajectories of the body parts due to high heels during walking and explains the causal relationship between the changes and high heels. Background: This study aims to indicate the comprehensive gait changes by high heels on the whole body for women wearing high heels and researchers interested in high-heeled walking. Method: The experiment was designed in which two different shoe heel heights were used for walking (1cm, 9.8cm), and twelve women participated in the test. In the experiment, 35 points on the body were tracked to extract the stride parameters, joint angles, and trajectories of the body parts. Results: Double support time increased, but stride length decreased in high-heeled walking. The knee inflexed more at stance phase and the spine rotation became more severe. The trajectories of the pelvis, the trunk and the head presented outstanding fluctuations in the vertical direction. Conclusion: The double support time and the spine rotation were changed to compensate instability by high heels. Reduced range of motion of the ankle joint influenced on the stride length, the knee flexion, and fluctuations of the body parts. Application: This study can provide an insight of the gait changes by high heels through the entire body.

• Geomechanics and Engineering
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• 제23권6호
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• pp.587-600
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• 2020

Shear-induced instability of jointed rock mass has greatly threatened the safety of underground openings. To better understand the failure mechanism of surrounding rock mass under shear, the flawed specimens containing a circular opening and two open joints are prepared and used to conduct direct shear tests. Both experimental and numerical results show that joint inclination (β) has a significant effect on the shear strength, dilation, cracking behavior and stress distribution around flaws. The maximum shear strength, occurring at β=30°, usually corresponds to a unifrom stress state around joint and an intense energy release. However, a larger joint inclination, such as β=90°~150°, will cause a more uneven stress distribution and a stronger stress concentration, thus a lower shear strength. The stress distribution around opening changes little with joint inclination, while the magnitude varys much. Both compression and tension around opening will be greatly enhanced by the 30°-joints. In addition, a higher normal stress tends to enhance the compression and suppress the tension around flaws, resulting in an earlier generation and a larger proportion of shear cracks.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권1호
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• pp.33-40
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• 2022

Objectives: Prolotherapy is a method that has gained popularity in recent years and has been reported to have positive short-term and long-term clinical results in maxillofacial surgery, especially temporomandibular joint (TMJ) hypermobility. This study aimed to evaluate the changes in the trabecular structure of mandibular condyles in patients who underwent prolotherapy due to TMJ hypermobility using the fractal analysis method. Materials and Methods: Forty-five patients who received dextrose prolotherapy at a concentration of 20% and fifteen control patients were included in the study. All patients had panoramic radiographs just before (T0) and six months after treatment (T1). The patients who received treatment were divided into three groups according to the number of prolotherapy injections. The regions of interest were selected from bone areas close to the articular surfaces of the condyles. The fractal dimension (FD) values were calculated. Results: The main effect of time on the FD value was significant [F (1, 56)=86.176, P<0.001]. This effect was qualified by a significant time×group interaction effect [F (3, 56)=9.023, P<0.001]. The decreases in FD values in all treatment groups between T0 and T1 times were significant (P=0.004). However, changes in FD values were not significant in the control group (P=0.728). Conclusion: Dextrose prolotherapy without the effect of the number of injections caused a decrease in FD values in the mandibular condyles over time.

• 대한정형외과스포츠의학회지
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• 제10권2호
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• pp.47-53
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• 2011

목적: 전방십자인대 재건술의 수가 증가하면서, 재건술의 실패로 인한 재재건술의 빈도 또한 증가하고 있다. 따라서 저자는 전방십자인대 재건술 후 발생한 이식건 실패의 원인 및 전방십자인대 재재건술 후의 임상적 결과를 분석하였다. 대상 및 방법: 1998년 2월부터 2010년 7월까지 전방십자인대 재건술 실패에 대하여 전방십자인대 재재건술을 시술받은 후 최소 12개월 이상 추시가 가능하였던 36예를 대상으로 하였다. 재건술 후 재재건술까지의 평균기간은 60(5~334)개월이었으며, 처음 전방십자인대 재건술을 시술 시 23예(63.9%)에서 동종 이식건을, 13예(36.1%)에서 자가 이식건을 사용하였다. 전방십자인대 재건술 실패의 주증상으로 불안정성이 가장 많았으며, 전방십자인대 재건술을 한번 시행 받았던 경우가 35예(97.5%), 두 번 시행 받았던 경우가 1예(2.5%)였다. 임상적 결과는 Lysholm 슬관절 점수, Tegner activity 점수를 이용하여 평가하였으며, 안정성은 Lachman 및 pivot shift 검사와 Telos device를 이용하여 평가하였다. 결과: 환자의 평균 추시 기간은 21(12~40)개월이었으며, 전방십자인대 재건술의 실패원인으로는 외상이 19예(52.8%)로 가장 많았고, 대퇴 터널의 부정위치가 13예(36.1%), 경골부 터널의 부정위치가 1예(2.8%), 골융합의 실패 3예(8.4%)로 나타났다. 전방십자인대 재재건술을 시행할 시 34예(94%)에서 동종이식건을, 2예(6%)에서 자가 이식건을 사용하였으며, 21예에서 반월상 연골판 손상이 동반되었다(내측 반월상 연골판 손상 14예, 외측 반월상 연골판 손상 7예). Lysholm 슬관절 점수는 술전 66.5점에서 술후 최종 추시시 92점으로 호전되었다(p<0.01). 환자의 대부분은 수술 결과에 만족(92%)하고 있었다. Tegner activity 점수는 술전 2.0점에서 술후 6.2점으로 호전되었다(p<0.01). Lachman 및 pivot shift 검사에서 33예, 30예가 Gr I 이하로 호전되었으며, Telos device를 이용한 안정성 검사에서는 양측 차이 정도는 술전 평균 15.5 mm에서 술후 최종 추시시 4.5 mm로 의미있게 호전되었다(p<0.01). 환자의 대부분은 수술 결과에 만족(92%)하고 있었다. 결론: 전방십자인대 재 재건술은 1년 이상 추시 결과 약간의 전방 불안정성이 존재하였으나, 임상적 결과 및 환자의 주관적 만족도에 있어서는 우수한 결과를 보였다.

• 대한족부족관절학회지
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• 제19권4호
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• pp.142-150
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• 2015

Purpose: Restoration of ankle stability through the strengthening exercise of peroneus muscles is considered an important factor for achievement of successful outcomes, in the rehabilitation program following ankle ligament injuries. However, there were few definitive data on normal muscle strength, including eversion power by peroneus muscles. This study was conducted to evaluate the muscle strength of ankle joint measured using an isokinetic dynamometer in normal Koreans. Materials and Methods: Sixty adults (120 ankles) were recruited and divided into three groups (20 in their twenties, 20 in thirties, and 20 in forties). Each group consisted of 10 males and 10 females. The selection criteria were no history of ankle injury and no evidence of instability. The peak torque, total work, and deficit ratio were measured using the Biodex$^{TM}$ (Biodex Medical Systems). Differences in muscle strength by age, gender and dominant versus non-dominant side were analyzed. Results: The peak torque of dorsiflexion was average 31.5 Nm at $30^{\circ}/s$ of angular velocity and 18.8 Nm at $90^{\circ}/s$; average 69.3 Nm ($30^{\circ}/s$) and 42.4 Nm ($90^{\circ}/s$) on plantarflexion; average 19.6 Nm ($30^{\circ}/s$) and 10.8 Nm ($90^{\circ}/s$) on inversion; average 12.9 Nm ($30^{\circ}/s$) and 8.0 Nm ($90^{\circ}/s$) on eversion. The deficit ratio of strength in women was average 61.1% of men on dorsiflexion; average 66.2% on plantarflexion; average 48.5% on inversion; average 55.4% on eversion. The deficit ratio in non-dominant foot was average 88.6% of dominant foot on dorsiflexion; average 90.1% on plantarflexion; average 85.1% on inversion; average 85.6% on eversion. Conclusion: The muscle strength of the ankle joint showed a tendency to weaken with age. There were significant differences in muscle strength by gender and dominancy. Further studies for comparison of patients with ankle instability, a comparison between before and after surgery for instability, the correlation between clinical outcomes and the recovery in muscle strength will be needed.

• 한국운동역학회지
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• 제20권4호
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• pp.395-406
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• 2010

The purpose of this study was to analyze the changes in kinematic and kinetic parameters of lower extremity joint according to rehabilitation period. Fourteen collegiate male athletes(age: $22.1{\pm}1.35$ years, height: $182.46{\pm}9.45cm$, weight: $88.63{\pm}9.25kg$) and fourteen collegiate athletes on functional ankle instability(age: $21.5{\pm}1.35$ years, height: $184.45{\pm}9.42cm$, weight: $92.85{\pm}10.85kg$) with the right leg as dominant were chosen. The subjects performed drop landing. The date were collected by using VICON with 8 camera to analyze kinematic variables and force platform to analyze kinetic variables. There are two approaches of this study, one is to compare between groups, the other is to find changes of lower extremity joint after rehabilitation. In comparison to the control group, FAI group showed more increased PF & Inversion at IC and decreased full ROM when drop landing. Regarding the peak force and loading rate, it resulted in higher PVGRF and loading. FAI group used more increased knee and hip ROM because of decreased ankle ROM to absorb the shock. And it used sagittal movement to stabilize. In terms of rehabilitation period, FAI group showed that landing patterns were changed and it increased total ankle excursion and used all lower extremity joint close to normal ankle. Regarding the peak force and loading rate, FAI group decreased PVGRF and loading rate. and also showed shock absorption using increased ankle movement. And COP variable showed that proprioception training increased stability during 8 weeks. The results of this study suggest that 8 weeks rehabilitation period is worthwhile to be considered as a way to improve neuromuscular control and to prevent sports injuries.