• 한국방사선학회논문지
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• 제6권4호
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• pp.299-303
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• 2012

자기공명 관절 조영술(Shoulder MR Arthrography)는 견관절(Shoulder joint) 의 복잡한 해부학적 구조에 관하여 정확한 영상평가를 진단하기 위해 시행 한다. 우리는 어께 상완골(Shoulder humerus) 의 다양한 position인 Neutral position, Internal rotation position, External rotation position 에 관하여 Shoulder joint의 해부학 적인 회전 변화가 견관절 자기공명(Shoulder MRI) 영상에 어떤 진단적 결과를 가져오는가에 대해 상호 비교 하였다. 또한 환자의 정확한 촬영자세 유지를 위해 촬영 보조기구를 만들었다. 이 보조기구는 Modeling 설계에 의해 우리가 직접 제작한 자기공명 견관절 조영술 보조 기구이다. 이 보조기구를 사용하여 촬영한 결과 다음과 같은 결론을 도출해 내었다. External rotation position 에 의한 Shoulder MRArthrography 검사가 Shoulder joint의 중요 해부학적 구조인 Biceps tendon, Supera-spiatus tendon, Sub-scapularis tendon, Labrum, Sub-acromial space 의 해부학적 평가에서 제일 적합하다는 진단적 평가를 얻었다.

• 한국터널지하공간학회 논문집
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• 제23권2호
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• pp.93-106
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• 2021

일반적으로 세그먼트 라이닝 터널은 프리캐스트 콘크리트 세그먼트를 연결하여 하나의 링을 구성하고 터널의 진행방향으로 링을 서로 결합하여 형성한 터널을 말한다. 세그먼트 라이닝의 구조적 특성은 세그먼트 이음부의 거동에 따라 크게 달라지므로 이음부를 적절하게 모델링해야 한다. 지반 하중을 받을 때 세그먼트 이음부는 회전에 저항하는 힌지로 작동하며, 모멘트-회전 관계는 비선형 거동을 보인다. 세그먼트 이음부가 라이닝 거동에 미치는 영향을 파악하기 위해 실제 설계에 통용되는 일본 기준 및 Janssen 모델을 적용하여 세그먼트 이음부의 모멘트-회전 관계를 설정하였다. 또한 이 논문은 지압강도를 기초로 세그먼트 이음부의 회전강성을 결정하는 방법을 제시하였다. 가상의 설계조건에서 기존 모델 및 제시된 방법을 적용해 세그먼트 이음부의 회전을 추정하고 세그먼트 라이닝과 이음부에서 발생하는 단면력을 계산하였다. 세그먼트 이음부의 회전이 증가할수록 이음부의 접촉 면적이 감소하므로 세그먼트 이음부의 지압강도를 확인해야 한다. 이 논문은 세그먼트 이음부의 지압강도를 검토하기 위해 세그먼트 이음부의 회전강성을 결정하고 지압강도를 계산하는 일관된 방법을 제시하였다.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.420-426
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• 2018

Background: The tibial tuberosity-trochlear groove (TT-TG) distance is used to determine the necessity of tibial tubercle osteotomy. We conducted this study to determine the extent to which each of the tibial tuberosity lateralization, trochlear groove medialization, and knee rotation angle affects the TT-TG distance in both normal and patella dislocated patients and thereby scrutinize the rationale for tuberosity transfer based on the TT-TG distance. Methods: Retrospective analysis of rotational profile computed tomography was done for patella dislocated and control group patients. Femoral anteversion, tibial torsion, knee rotation angle, tuberosity lateralization, and trochlear groove medialization were assessed in all patients. Relationship of these parameters with the TT-TG distance was investigated to evaluate their effects on the TT-TG distance. Results: We observed that the patellar dislocation group, compared to the control group, had increased TT-TG distance (mean, 19.05 mm vs. 9.02 mm) and greater tuberosity lateralization (mean, 64.1% vs. 60.7%) and tibial external rotation in relation to the femur (mean, $7.9^{\circ}$ vs. $-0.81^{\circ}$). Conclusions: Tuberosity lateralization and knee rotation were factors affecting patellar dislocation. These factors should be considered in addition to the TT-TG distance to determine the need for tibial tubercle osteotomy in patients with patellar dislocation.

• 한국운동역학회지
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• 제27권1호
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• pp.67-74
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• 2017

Objective: The purpose of this study was to apply a general linear model in statistics to marker position vectors used to study human joint rotational motion in biomechanics. Method: For this purpose, a linear model that represents the effect of the center of hip joint rotation and the rotation of the marker position on the response was formulated. Five male subjects performed hip joint functional motions, and the positions of nine markers attached on the thigh with respect to the pelvic coordinate system were acquired at the same time. With the nine marker positions, the center of hip joint rotation and marker positions on the thigh were estimated as parameters in the general linear model. Results: After examining the fitted model, this model did not fit the data appropriately. Conclusion: A refined model is required to take into account specific characteristics of longitudinal data and other covariates such as soft tissue artefacts.

• 한국생산제조학회지
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• 제19권6호
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• pp.797-803
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• 2010

A method has been developed to tune the static stiffness at a rotation joint considering the whole machine tool system by interactive use of finite element method and experiment. This paper describes the procedure of this method and shows the results. The method uses the static experiment on measurement model which is set-up so that the effects of uncertain factors can be excluded. For FEM simulation, the rotation joint model is simplified using only spindle, bearing and spring. At the rotation joint, the damping coefficient is ignored, The spindle and bearing is connected by only spring. By static experiment, 500 N is forced to the front and behind portion of spindle and the deformation is measured by capacitive sensor. The deformation by FEM simulation is extracted with changing the static stiffness from the initial static stiffness considering only rotation joint. The tuning static stiffness is obtained by exploring the static stiffness directly trusting the deformation from the static experiment. Finally, the general tuning method of the static stiffness of machine tool joint is proposed using the force stream and the modal analysis of machine tool.

• 대한물리의학회지
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• 제13권1호
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• pp.99-105
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• 2018

PURPOSE: The aim of this study was to evaluate the concurrent validity and clinical usefulness of the universal plastic goniometer to measure the range of motion of the internal and external rotation of the hip joint using the three dimensional motion analysis which can analyze the joints and segment movements in the most objective and quantitative method. METHODS: Clinical and kinematic data were collected from thirty individuals using a universal plastic goniometer and a ten camera motion analysis system. Passive hip rotation range was obtained three trials for left and right hip joints using two measure methods simultaneously. RESULTS: There were significant differences between all matching measures of the two measures of internal and external rotation of the hip joint (p<.05). The relationship between the two tests for all measurements of the internal and external rotation of the hip was statistically significant with correlation coefficient form r=.87 to .96. (p<.01). CONCLUSION: Clinical measurement of the internal and external rotation of the hip using a universal plastic goniometer is effective to assess the hip condition. However, application of universal plastic goniometer requires careful attention in more accurate evaluation and research verification of the internal and external rotation of hip joint.

• 한국운동역학회지
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• 제28권2호
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• pp.127-134
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• 2018

Objective: In a statistical linear model estimating the center of rotation of a human hip joint, which is the parameter related to the mean of response vectors, assumptions of homoscedasticity and independence of position vectors measured repeatedly over time in the model result in an inefficient parameter. We, therefore, should take into account the variance-covariance structure of longitudinal responses. The purpose of this study was to estimate the efficient center of rotation vector of the hip joint by using covariance pattern models. Method: The covariance pattern models are used to model various kinds of covariance matrices of error vectors to take into account longitudinal data. The data acquired from functional motions to estimate hip joint center were applied to the models. Results: The results showed that the data were better fitted using various covariance pattern models than the general linear model assuming homoscedasticity and independence. Conclusion: The estimated joint centers of the covariance pattern models showed slight differences from those of the general linear model. The estimated standard errors of the joint center for covariance pattern models showed a large difference with those of the general linear model.

• 대한산업공학회지
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• 제25권1호
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• pp.56-66
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• 1999

Shoulder joint is the most movable joint in human body with, at least, three degrees of freedom, since there are at least three bones and five joints involved in shoulder movement. Due to the complexity of the shoulder joint and the lack of appropriate anatomical data, modeling of the shoulder joint has been known to be extremely difficult. In many biomechanical models being used, shoulder joint is considered as a fixed point and it is also assumed that the shoulder joint does not noticeably move during the shoulder movement. However, such an assumption is not valid in real applications and causes inaccuracy, especially, in the area of workspace evaluation. The reachable area generated by a human becomes somewhat different from that of current models for those models fail to appropriately reflect the movement of shoulder joint's center of rotation. In this study, the location of the shoulder joint's center of rotation was obtained in relation to the location of humerus, on which a new model for reach envelope generation was developed for workspace evaluation. From the experiments conducted for three subjects, the initial location of the center of rotation was determined for each subject and subsequent changes in the instantaneous center of rotation were drawn as a function of flexion and abduction of the shoulder. Based on the regression analysis, the study suggested a new method for the generation of reach envelope. Comparisons were also made among real reach envelopes obtained from the experiment, the ones from the model, and the ones from the new method suggested in the study. As a result, the prediction errors incurred from the new method were significantly reduced when compared to the ones from the current approach.

• 대한통합의학회지
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• 제5권4호
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• pp.41-48
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• 2017

Purpose : The purpose of this study was to verify the relationships among the knee adduction moment, hip rotation range, strength of hip rotators, and Foot Posture Index of healthy young adults. Method : Thirty-two healthy adults(24 male, 8 females) participated in this study. Subjects performed 5 walking trials to evaluate the knee adduction moments using a three-dimensional motion analysis system. Hip rotation ranges and hip rotator strengths were measured using a standard goniometer and a handheld dynamometer, respectively. The mean of three trials of clinical tests was used for data analysis. Results : The first peak knee adduction moment was significantly correlated with the hip rotation ranges and hip rotator strengths (P<.05). The second peak knee adduction moment was showed significant correlations with hip external rotation and rotation ratio. There were no correlations between Foot Posture Index and all knee adduction moments (P>.05). Conclusion : This study suggests that imbalances of the range of motion and strength of the internal and external rotation of the hip joint can affect knee adduction moments. The impact may exacerbate musculoskeletal disorders such as osteoarthritis of the knee. Therefore, further studies should be conducted to evaluate the effects of clinical interventions to correct these imbalances on the reduction of the knee adduction moments in patients with knee osteoarthritis.

• The Journal of Korean Physical Therapy
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• 제34권4호
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• pp.140-148
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• 2022

Purpose: The purpose of this study was to investigate the effects of the scapulothoracic mobilization on subject with lateral epicondylalgia. This was done through lateral slide scapular test, grip strength, visual analogue scale, glenohumeral joint external rotation range of motion. Methods: Before the experiment, Lateral slide scapular test, grip strength, visual analogue scale, glenohumeral joint external rotation range of motion were measured. Scapulothoracic joint mobilization was applied and then measurements were taken again to compared the changes. Results: After applying the scapulothoracic joint mobilization, lateral slide scapular test, grip strength, visual analogue scale, glenohumeral joint external rotation range of motion significantly improved. Conclusion: This study found that the scapulothoracic mobilization was effective in improving functional aspects and pain on subject with lateral epicondylalgia. The results suggest that the scapulothoracic joint mobilization is a significant considered intervention method that could be used for subject with lateral epicondylalgia.