• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.467-479
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• 2009

The purpose of this study was to present the quantitative data which riders can utilize teaching field by comparison analysis of kinematics according to skill level of rider during 2 strides rising trot with the JeJu's-Horse. Participated subjects was consisted of total 10 riders(unskilled: n=5, skilled: n=5). The method of experiment & analysis was based on 3D cinematography. Variables were consisted of temporal, linear & angular kinematics by each event & phase. The skilled assigned more ratio of elapsed time in air than support phase, had the less range of motion in up-down direction and more consistent velocity in lateral & forward direction and performed periodic up-down movement with alignment in vertical direction according to elapsing of phases. The skilled more flexed at elbow and extended backwardly according to elapsing of phases, while more flexed forwardly at hip & knee and plantarflexion at ankle. The skilled postured backward extension but the unskilled do forward flexion. That is, It was considered that the unskilled continued more unstable posture than the skilled during 2 strides in rising trot.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.435-448
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• 2009

The purpose of this study was to investigate the kinemaitc gait parameter of lower extremities with different gait conditions(level walking, stairs, ramp) in old adults. Fourteen healthy older adults participated in this study and kinematic data were measured using 3D motion analysis system(Vicon, Oxford Metrics, England). Statistical analysis was used one-way ANOVA to know the difference of lower extremities angle at each gait phase with a different gait conditions. In sagittal plane, pelvic anterior tilt increased in stairs and ramp climbing and hip and knee flexion increased in stairs climbing but ankle dorsiflexion increased in ramp climbing. In frontal plane, pelvic was up in stairs and hip abduction and adduction more changed in stairs climbing than level walking. Knee varus and ankle inversion increased in stair climbing. In horizontal plane, pelvic internal rotation increased in stairs and ramp climbing and knee internal rotation increased in stairs climbing but ankle external rotation increased in stairs climbing. This results was shown that the stairs and ramp climbing changed the kinematic gait parameters of lower extremities in healthy old adults.

• Journal of Navigation and Port Research
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• v.46 no.3
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• pp.168-178
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• 2022

In this study, the resistance test, the vertical static angle of the attack test and VPMM test will be conducted to estimate the maneuverability of underwater vehicles with ahead propeller. The vertical static test will be conducted within the range of -40deg to 40deg, to investigate the cross-flow drag at high incidence angles. The tests will be conducted by dividing the propeller rotation into a case in which the propeller rotates at a specific rpm, and a case in which the propeller rotates naturally, according to the towing speed. Hydrodynamic coefficients of vertical direction will be estimated by the captive model tests. Additionally, the vertical dynamic stability index based on estimated hydrodynamic coefficients will be calculated and the impact of the propeller revolution state on the index will be investigated. The results are expected to be used as reference test data for underwater vehicles with ahead propeller.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2008.11a
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• pp.99-108
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• 2008

견관절 전방 탈구의 치료 방법을 결정하는데 있어서 중요한 점은 탈구를 유발한 병태 생리에 대한 충분한 숙지와 함께 적절한 환자의 선택과 치료 결과에 대한 환자의 기대치를 파악하여 그에 맞는 치료를 선택하는 것이 중요하다. 탈구의 횟수에 있어서 첫 탈구이거나 아주 적은 횟수의 탈구로 환자가 일상 생활에 어려움을 호소하지 않는다면 보존적 치료를 시행해야 할 것이며, 수술적 치료의 경우에 환자의 병변 상태나 그 원인 인자에 대한 평가가 정확히 이루어진 후 시행되어야 한다. 환자의 기대치는 일반인의 경우 수상 이전의 활동도의 회복보다는 안정성이 중요할 것이며, 운동 선수인 경우에는 안정성이 회복 되었더라도 운동에 다시 복귀하지 못한다면 만족도는 매우 떨어질 것이다. 이렇듯 의사의 능력이나 욕망 보다는 환자의 활동 정도와 견관절의 병적 상태, 환자의 요구에 맞는 치료방법을 선택해야 할 것이다.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.5
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• pp.65-73
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• 2001

In this paper, a mobile system using multi-wheel steering and driving mechanism is proposed to maximize maneuverability of the wheeled mobile system. Among various possible configurations, the two-wheel steering and driving systems, which is minimal in structural requirement, is proposed to reduce the complexity in actual design and difficulties in control. The system possesses three or four degrees of freedom depending on the orientations of two wheels, one or two for driving and two for steering, which implies that the system's mobility is always less than three DOF. The proposed system, nonetheless, can exactly emulate characteristics of the omnidirectional motion as long as the planned path is smooth i.e., the curvature changes continuously while velocity is not zero. Efficient kinematic and dynamic control algorithms are proposed for position and orientation control of the proposed wheeled mobile system.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.102-108
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• 1999

Purpose : The purpose of this study was to evaluate the clinical results of bone-patellar tendon-bone(B-PTB) allograft for ACL reconstruction without mechanical tensioning device. Material and Method : Forty-six knees in 43 patients were reviewed and evaluated with subjective evaluation, objective evaluation, Telos stress arthrometer and modified Feagin Scoring System. The average age at the time of operation was 27 years(range, 18-42) and the average follow up period was 41 months(range, 22-79). Authors reconstructed ACL using B-PTB allograft which was prepared by rehydration preoperatively without tensioning by mechanical tensioning device. The tension for allograft was obtained by full flexion and extension intraoperatively. All operation were performed arthroscopically by two-tunnel method to avoid the mismatching of allograft tendon length. Result : The modified Feagin Scoring System revealed 39 cases(84.7%) with excellent or good results and 7 cases(15.3%) with fair or poor results. The mean follow-up Lysholm Knee Score was 84. Telos arthrometer revealed 41 cases had an injured-to-uninjured difference of 5 mm or less(mean 2.3mm). The range of motion of knee was nearly normal and there was no extension lag in any cases at last follow up. Conclusion : Clinical results using B-PTB allograft showed less morbidity than B-PTB autograft. The intraoperative tensioning method by full flexion and extension without mechanical tensioning device was not bad. Therefore, B-PTB allograft is a good substitute material in reconstruction of the ACL.

• Journal of the Korean Arthroscopy Society
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• v.14 no.2
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• pp.107-113
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• 2010

Purpose: To evaluate the outcome of the two-bundle anterior cruciate ligament reconstruction with single femoral tunnel and tibialis anterior tendon allograft and to determine any functional advantages. Materials and Methods: From June 2006 to March 2008, we performed single femoral tunnel and two-bundle ACL reconstruction with tibialis anterior tendon allograft in 26 cases. Mean age was 35.5 years. 20 cases were male and 6 cases were female. Average follow-up period was 2 years and 5 months, range from 1 year to 3 years and 5 months. Subjective and objective parameters were utilized in analyses, such as the mean range of motion, Lysholm knee score, Tegner activity score, Lachman test and IKDC score. Results: Postoperative mean Lysholm knee score, IKDC Evaluation Form, Tegner activity scale, Pivot shift test, and anterior displacement by the Telos stress test demonstrated statistically significant differences compared to the preoperative. Conclusion: Two-bundle anterior cruciate ligament reconstruction with single femoral tunnel showed good clinical results and was good operative technique.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.176-182
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• 2003

Purpose : The purpose of this study is to describe the surgical technique of ACL reconstruction with the flexible reamer and evaluate the clinical results of this method. Materials and Methods : Twenty four patients who followed for 12 months were included. The results were evaluated by Lachman test, KT-2000 arthrometer, Lysholm score, and postoperative roentgenogram of the knee. Results : The range of motion of the affected knee was acceptable except one case(10 to 90 degree) and at the last follow up, two cases were positive in Lachman test. Mean Lysholm knee scoring scale was 63.7 point preoperatively and 91.4 point at the last follow up. The results of KT-2000 arthrometer was 6.6mm preoperatively and 1.5mm at the last follow up. In operative time, there were decrease of mean 13.5 minute than ACL reconstruction without the flexible reamer, Conclusion : ACL reconstruction with the flexible reamer achieves the ideal isometric point of tibia and femur with no difficulty, proper notchplasty preventing from the impingement, and lessens the operative time.

• Journal of the Korean Arthroscopy Society
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• v.4 no.2
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• pp.117-122
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• 2000

Purpose : To compare the mid term with long term follow up results of the anterior cruciate ligament(ACL)> reconstruction using patellar tendon. Materials and Methods : Seventy-six cases, which could be followed up more than 2 years were included in this study. They were classified into two groups, mid-term group(41 cases) with mean follow-up periods of 2 years and 10 months and long-term group(35 cases) off years and 6 months. Clinical and radiological results and peripatellar complications were evaluated & compared. Results . There was no statistically significant difference in radiological finding and anterior instability between two groups. However, the incidence of anterior knee pain, paresthesia at incision site, kneeling pain, crepitus and quadriceps weakness was lower in long-term group than in mid-term group. Conclusion : ACL reconstruction using patellar tendon graft could successfully restone the stability of knee joint, but there are some complications in donor site and patellofemoral joint. However this complications were gradually decreased with long term follow-up.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.525-535
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• 2016

The purpose of this study was to evaluate the effect of thoracic dynamic stretching with elastic band on the ROM and ball speed for baseball player. For this purpose, 11 baseball players of the I city high school and university performed thoracic dynamic stretching with elastic band before throwing a ball. After stretching, we measured the ROM and ball speed and compared. The results were as follows. First, ROM after stretching showed a significant increase immediately compared with before stretching. Second, the speed of the ball was significantly increased after stretching compared with before. These results indicated that thoracic dynamic stretching with elastic band for baseball players might have a positive effect on ball speed as well as ROM.