• Journal of Life Science
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• v.14 no.3
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• pp.484-489
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• 2004

Artificial joint replacement is one of the major surgical advances of the 21th century. The primary purpose of a TKA (Total Knee Arthroplasty) is to restore normal knee Auction. Therefore, ideally, a TKA should: (a) maintain the natural leverage of the knee joint muscles to ensure generating adequate knee muscle moments to accomplish daily tasks such as rising from a chair or climbing stairs;(b) allow the same range of motion as an complete knee; and (c) provide adequate knee joint stability. Four individuals (2 peoples after surgery one year and 2 peoples after surgery three years) participated in this study. All they were prescreened for health and functional status by the same surgeon who performed the operations. Two days of accommodation practice occurred prior to the actual strength testing. The isometric strength (KIN-COM III) of the quadriceps and hamstring were measured at 60$^\circ$ and 30$^\circ$ of knee flexion, respectively. During isokinetic concentric testing, the range of motion was between 10$^\circ$ to 80$^\circ$ of knee flexion (stand-to-sit) and extension (sit-to-stand). for a given test, the trial exhibiting maximum torque was analyzed. A 16-channel MYOPACTM EMG system (Run Technologies, Inc.) was used to collect the differential input surface electromyographic (EMG) signals of the vastus medialis (VM), vastus lateralis(VL), rectus femoris (RF) during sit-to-stand and stand-to-sit tests. Disposable electrodes (Blue SensorTM, Medicotest, Inc.) were used to collect the EMG signals. The results were as follows; 1. Less maximum concentric (16% and 21% less for 1 yew man and 3 years mm, respectively) and isometric (12% and 29%, respectively) quadriceps torque for both participants. 2.14% less maximum hamstrings concentric torque for 1 year man but 16% greater torque for 3 years mm. However, 1 year man had similar hamstring isometric peak torque for both knees. 3. Less quadriceps co-contraction by 1 year man except for the VM at 10$^\circ$-20$^\circ$ and 30$^\circ$-50$^\circ$ range of knee flexion.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.407-415
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• 2014

The purpose of this study is to identify the relation between isokinetic strength of knee extensors and angular velocity of knee joint during fente motion in elite fencers by three disciplines and gender, and to provide the preliminary data for developing the training program and rehabilitation program to enhance sports-performance by three disciplines and gender. Total 31 elite fencers who trained at the national training center of the Korean Olympic Committee (KOC) participated in this study.; 10 fleuret (4 males), 10 epee (6 males) and 11 sabre (5 males). Subjects were measured eccentric and concentric isokinetic strength (PT/BW, WK/BW) of the knee extensors at angular velocity of $60^{\circ}/s$, $180^{\circ}/s$ and $300^{\circ}/s$, and flexion (P1) and extension (P2) angular velocity of knee joint during fente motion. To examine the relationship between isokinetic strength of knee extensor and angular velocity of knee motion, Pearson's correlation coefficient (r). ${\alpha}=.05$ was considered significant. In conclusion, the relationship of isokinetic strength of knee extensors and angular velocity of knee was different depending on three disciplines and gender.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.323-330
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• 2009

Objectives: There are many reasons to restrict extension of knee. Unless we can find any structural deformities from patients, we don't have any clue of helping this condition except give them some instruction of exercise of strengthening anterior thigh muscles and releasing extensor muscle group of lower extremities. In this study, the author reports new case, using technique of releasing restriction of knee movement based on Sacro Occipital Technique. Method: From the day of notifying 14yrs. old patient's extension restriction of knee, it had have 7 trials of having S.O.T category Ⅰ. technique procedure. Result: The patient can stand without extension restriction of knee. Conclusion: In many case, muscle soft tissue work helps releasing hamstring tension so that we can make patient stand with straightly extended knee position but if this method is not working then S.O.T category Ⅰ. technique procedure may be considerable to improve this condition.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.75-83
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• 2008

The purpose of this study was to evaluate the correlation between joint moment and joint position angle according to the different walking speeds. According to the different walking speeds(1.5m/s, 1.8m/s, 2.1m/s), experiments were terminated by 8 male subjects. In conclusion, 1. The peak extensor moment of knee joint increased by increasing walking speed, however, walking speed didn't have an effect on peak flexor and abductor moment of knee joint. 2. The position angle of knee joint increased movement of flexion, but other position angles of knee joint didn't have difference when the peak extensor moment generated. 3. The peak joint moment of hip significantly increased in extension, flexion and abduction by increased walking speed. 4. The hip position angle showed more flexible at the hip peak flexor/extensor moment generated. 5. The co-ordination pattern between peak knee joint moment and knee position angle were mathematically modeled by using a least square method. We could get the high level value of R2. We expect to apply this results for evaluating the physical faculty of knee joint.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.83-92
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• 2008

Y. W. KIM, Y. J. KIM, Mechanical Properties of Unilateral & Bilateral Movements in Isokinetic Knee Extension and Flexion. Korean Journal of Sport Biomechanics, Vol. 18, No. 3, pp. 83-92, 2008. The purpose of this study was to examine the mechanical properties and patterns of bilateral and unilateral movement under varying velocities and movement patterns. The unilateral and bilateral isokinetic knee extension and flexion were taken for three speeds of 13 healthy male subjects. Although there was bilateral facilitation at the speed of $450^{\circ}$/s for the bilateral movement of knee extension, as a whole there was less resultant torque and power of bilateral movement than summed unilateral under knee flexion and extension of 3 velocity condition. There was significant correlations between bilateral deficits within individuals observed for an the same movement($120^{\circ}-240^{\circ}$ flexion, $120-240^{\circ}$ extension, $240^{\circ}-450^{\circ}$ extension), which means that same agonist was recruited. On the contrary, although there was a tendency of a similar pattern of the individuals bilateral deficit according to the varying velocities, there was not a significant correlations between bilateral deficits of flexion and extension within individual, which means that different agonist was recruited. With the analyses of this results the individuals neuromuscular characteristics and the effecting factors for bilateral movement can be speculated upon.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.161-169
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• 2008

The purpose of this study was to investigate kinetic variables of the lower extremity during walking on three different stair widths in healthy adults. Ten healthy college-aged adults($23.5{\pm}3.5$) recruited for this study. Each stairs with the same height and length(l8cm and 90cm) under the Korean Constructional Law but three different widths(26cm, 31cm and 36cm) were conducted for this study. One force plate(9286AA, Kistler Co.) was put on third stairs. One-way ANOVA was performed to find the stair width effects during stair walking and the following findings ware obtained. There was significantly decreased in ankle resultant joint moment at Pull-Up phase(p<.05) and, significantly increased in knee extension moment during mid-stance phase as stair width increase(p<.05), but there was no significance in ankle resultant joint moment was found at Forward Continuance Phase in Ascending Stair Walking and There was significantly increased in ankle resultant joint moment as stair width increase during mid-stance phase(p<.05) and no significance in knee and hip resultant moments among the stair width in descending stair walking.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.3
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• pp.153-160
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• 2017

Gait analysis has been conducted in various environments, but the biomechanics during the transition from uphill walking to downhill walking have not been reported. The purpose of this study is to investigate the knee and ankle joint kinematics and kinetics during walking on a triangle-shaped slope compared with those during level walking. Kinematic and kinetic data of eighteen participants were obtained using a force plate and motion capture system. The greater peak ankle dorsiflexion angle and moment and the peak knee extension moment were observed (p<0.05) during both uphill and downhill walking on the triangle-shaped slope. In summary, uphill walking on a triangle-shaped slope, which showed a peak knee flexion of more than $50^{\circ}$ with greater peak knee extension moment, could increase the risk of patellofemoral pain syndrome. Downhill walking on a triangle-shaped slope, which involved greater ankle dorsiflexion excursion and peak ankle dorsiflexion, could cause gastrocnemius muscle strain and Achilles tendon overuse injury.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.449-455
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• 2003

일어서는 동작은 일상생활에서 하는 가장 일반적인 행동 중의 하나이며, 다른 동작으로의 전환을 위한 준비자세이기도 하다(Riley PO 등 1991). Corrigan D 등(2001)에 따르면 1987년 65세 이상의 공공시설(병원, 재활시설 등)에서 기거하지 않는 약 2백만 명의 노인이 일어서는 동작에서 어려움을 느낀다고 한다. 또한 무릎의 신근(신전을 담당하는 근육)이 약화된 환자들에게도 앉은 자세에서 일어서는 동작은 무릎에 가장 무리를 주는 동작 중의 하나로 작용한다. (중략)

• 한국체육학회지인문사회과학편
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• v.51 no.4
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• pp.419-425
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• 2012

The purpose of the study was to investigate the effects of knee brace on anterior cruciate ligament injuries risk factors during one-legged landing of female gymnasts. Eleven female gymnasts were recruited and performed randomly one-legged drop landing in height of her's knee with (3times) and without (3times) knee brace. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. Data were analyzed with paired samples t-test. Female gymnasts with knee brace showed more reduced the distance from ankle joint center to knee joint center in sagittal plane and knee maximum joint torque than without knee brace. In conclusion, Female gymnasts with knee brace reduced anterior cruciate ligament stress.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1423-1424
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• 2011