• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.85-94
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• 2006

The purpose of this study was to analyze the kinematics variables of during forehand stroke by stance patterns. Eight high school tennis players were chosen for the study, who have never been injured for last six months, in Busan. They performed horizontal swing and vertical swing that it was done each five consecutive trial in the condition of square, open and semi-open stance. It was filmed by 6 video camera and used with 3-dimensional motion analyzer system. The following kinematic variables were analyzed in relation to angle of segment( shoulder, hip and knee joint). The conclusion were as follow: 1. The angle of hip joint represented at impact that horizontal swing was not significant difference by stance patterns but vertical swing was increased in open stance than square and semi-open stance. 2. The angle of both knee was not significant difference between all stance types and swing patterns. 3. The angle of shoulder, hip and knee joint rotation showed that open stance was increased than square and semi-open stance in all swing types and event.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3991-3998
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• 2012

The aim of this study was to effect of muscle activity on muscle architectural of medial gastrocnemius in chronic stroke patient based on ankle joint degree. The subjects of this study were 10 chronic stroke patients modified Ashworth scale(MAS) 2. Ultrasonographic and dynamometer was measured during resting and maximum voluntary isometric contraction(MVIC) on muscle thickness, pennation angle, fascicle length, MVIC. Result from analysis showed that muscle thickness was thinner in the paretic side than in the non-paretic side(p<.001) and the more plantarflexion increased, the thinner muscle thickness became. And at the time of resting rather than of MVIC significant(p<.001). Result from analysis showed that penneation angle was smaller in the paretic side than in the non-paretic side(p<.001) and the more plantarflexion increased, the larger pennation became. And at the time of resting rather than of MVIC significant(p<.001). Result from analysis showed that fascicle was shorter in the paretic side than in the non-paretic side(p<.001) and the more plantarflexion increased, the shorter fascicle length became. And at the time of resting rather than of MVIC significant(p<.001). The results of this study showed that effect of muscle activity on muscle architectural of medial gastrocnemius in chronic stroke patient based on ankle joint degree. Therefore, Ultrasonographic evaluation of chronic stroke patients according ankle joint degree and muscle activity in the clinical diagnosis and therapy is considered a very useful data.

• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.109-116
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• 2023

The purpose of this study was to investigate the influence of gender and load carriage difference on the lower extremity kinetics during stair descent. Ten healthy males and 10 healthy females were recruited (n=20). In the Maximum resultant velocity, it showed more velocity was decreased with difference by the change of gender (males>females) and load carriage (30%, 20%, 10%> 10%). And, resultant velocity showed interaction between gender and a load (load>gender). Main effect by gender during stair descent showed leg length was decreased in females than that of males at initial contact phase. Also, main effect by gender during stair descent showed more hip, knee flexed and plantar flexion of ankle joint in females than that of males. In the kinetics variables, main effect by gender during stair descent showed more higher reaction force of medial-lateral direction, and leg stiffness in males than that of females. We found that females successfully accommodated a load during stair descent by decreasing the range of motion of the hip joint angle and resultant velocity of movement. Males, on the other hand, require greater medial-lateral, vertical reaction force, and leg stiffness to accommodate a load, and control of momentum.

• Journal of Korean Foot and Ankle Society
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• v.1 no.1
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• pp.11-14
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• 1997

Hallux valgus is a complex deformity which contains static subluxation of the first metatarsophalangeal joint with lateral deviation of the great toe and medial deviation of the first metatarsal bone. Among the several parameters, radiographic indices are the important ones in the choice of the treatment method. Even though, the normal values of the western peoples are already estabilished, there was no standard values for Korean who has different genetics, and cultural background, till now. So, we tried to estimate the noraml values of the HVA (hallux valgus angle ), IMA ( Intermetatarsal angle) and DMAA (Distal Metatarsal Articular surface Angle) in a normal adult. Fifty normal adult (each 25 male and female) were chosen and took 100 cases of foot radiograph and radiologic indices of the hallux valgus were measured. Average age at the investigation was 34.5 years old. The average HVA is $13.3^{\circ}$, IMA is $8.5^{\circ}$ and DMAA is $34.6^{\circ}$.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.312-318
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• 2003

The purpose of this study were to determine the effect on grip and pinch strength with elbow and wrist angle change. 112 college students, 88 males, and 24 females aged 19 to 34 years, participated in the study. A Grip and pinch strength was measured in two elbow position($0^{\circ}$ and $90^{\circ}$) and three wrist position($80^{\circ},\;0^{\circ},\;23^{\circ}$). The data were analyzed by mean and deviation, and t-test using the PC/SAS system. These results were obtained as follows; 1. There was a more strength grip and pinch power in $0^{\circ}$ than $90^{\circ}$ elbow flexion at three wrist angle. 2. There was a significant high grip and pinch strength in $23^{\circ}$ dorsiflexion among three wrist angle(p<0.01). 3. The grip and pinch strength power was measured higher in male than female every elbow and wrist angle(p<0.01).

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.241-246
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• 2009

Since inappropriate muscle forces mean that people cannot perform some activities related to roles of the muscle, muscle forces have been considered as an important parameter in clinic. Therefore, many methods have been introduced to estimate muscle forces indirectly. One of the methods is muscle tissue dynamics and it is widely used in commercial softwares including musculoskeletal model, such as SIMM. They, however, need motion data captured from 3-dimensional motion analysis system. In this study, we introduced an algorithm to estimate muscle forces in real-time by using joint angles. The heel-rise movements were performed for a normal with 3-dimensional motion analysis system, EMG measurement system, and electrogoniometers. Joint angles obtained from electrogoniometers and EMG signals were used to estimate muscle forces. Simulation was performed to find muscle forces using motion data which was imported into musculoskeletal software. As the results, muscle lengths and forces from the developed algorithm were similar to those from commercial software in pattern. Results of this study would be helpful to implement a tool to calculate reasonable muscle forces in real-time.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.11 no.1
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• pp.39-44
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• 2013

Purpose : The purpose of present study is to evaluate the joint angles of legs in the standing posture for six patients with unilateral knee osteoarthritis. Methods : The participants underwent unilateral total knee replacement. A motion analysis was used to measure the joint angles of the hip, knee, and ankle. The measurements were taken before the surgery, one week and two weeks after the surgery. Both sides of the legs were evaluated. Results : This result showed that after a certain healing period, both hip joint angles showed a significant difference while there was no significant difference in the knee and ankle joint angles. After surgery, the angle of ankle dorsiflexion was smaller on the operated side than the opposite side compared to the pre-surgery measurements. Conclusion : After surgery, the asymmetry in a standing position left unchanged due to contracture of the knee joint and tightness in the hamstring muscle. Therefore, when physiotherapists plan an initial exercise programs for TKR patients, it is essential to apply adequate exercises which consider the contracture of the leg joints.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1722-1729
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• 2005

In this paper, we used the quadruped walking robot Titan-VIII in order to carry out this simulation of sway compensation trajectory. The attitude angle ${\phi}_r$ and ${\phi}_p$ is obtained from 3-D motion sensor that is attached at the center of robot body and the attitude control carried out at every 10[ms] for stable gait of robot. Duty factor, that is fixed at 0.5. When we change period T into 1.5, 2.0, 3.0[sec] each and moving distance per period is changed into 0.2, 0.3(m), we sim띠ate several walking experiment of robot. and then we analyze the experiment results if there are any difference between the imaginary ZMP and actual ZMP of robot and the stable gait of robot is realized.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.127-133
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• 2024

The elbow joint is made up of three different bones. X-rays or other radiological exams are commonly used to diagnose elbow injuries or disorders caused by physical activity and external forces. Previous research on the elbow joint reported a new examination method that meets the imaging evaluation criteria in the tilt position by Z-axis elevation of the forearm. Therefore, this study aims to design an optimized instrument and develop an aid applicable to other upper extremity exams. After completing the 2D drawing and 3D modeling design, the final design divided into four parts was fabricated with a 3D printer using ABS plastic and assembled. The developed examination aid consists of a four-stage Z-axis elevation tilt angle function (0°, 5°, 10°, and 15°) and can rotate and fixate 360° in 1-degree increments. It was designed to withstand a maximum equivalent stress of 56.107 Pa and a displacement of 1.6548e-5 mm through structural analysis to address loading issues caused by cumulative frequency of use and physical utilization. In addition to X-ray exams of the elbow joint, the developed aid can be used for shoulder function tests by rotating the humerus and also be applied to MRI and CT exams as it is made of non-metallic materials. It will contribute to the accuracy and efficiency of medical imaging diagnosis through clinical applications of various devices and medical imaging exams in the future.