• Journal of Fashion Business
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• v.27 no.5
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• pp.93-107
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• 2023

This study aimed to design a knee brace with dry electrode EMS (Electrical Muscle Stimulation) for elite badminton players suffering from knee pain and assess its effectiveness in relieving pain and improving mobility. The assessment measured knee joint range of motion (ROM), Sargent jump height, and pain perception using a visual analog scale (VAS). Four experimental groups were established: stability, pain induction after 100 squats, muscle soreness induction with a regular knee brace, and muscle soreness induction with the EMS knee brace. The most suitable knee brace was selected from four samples to design the EMS knee brace. The conductive fabric was integrated into the inner surface of the knee brace to enhance EMS conductivity for the quadriceps muscles. Tensile strength tests showed that the dry electrode did not significantly affect the physical functionality of the knee brace.Regarding knee joint ROM and Sargent jump height, the EMS knee brace outperformed muscle soreness induction with a regular knee brace and wearing a standard knee brace. VAS measurements demonstrated that the EMS braces effectively alleviated pain perception in most cases. The results indicate the potential for developing EMS braces to alleviate pain and prevent injuries for athletes across various sports.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.93-96
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• 2010

This study evaluates usefulness of the developed assistant device by taking projection of patellofemoral joint in emergency patients who were doubt posterior cruciate ligament injury in knee joint. The subjects of experiment were patients who visited Eul-Ji University Hospital due to knee injury from January 2006 to December 2006. Seventeen patients, who took the Knee post stress view, Knee merchant view, Knee Seo's view to use assistant device and Knee MRI. To make assistant device of $170{\times}50{\times}70\;cm$, we evaluated its usefulness by measuring posterior dislocation of tibia. Seo's view is more accurate to make judgment of posterior cruciate ligament injury than original knee post stress view. Interval difference of posterior dislocation of original knee post stress view is $6.17{\pm}3.04$ and Seo's view is $8.74{\pm}4.47$. The results show injury of patellofemoral joint, vertical fracture of patella and posterior cruciate ligament injury by taking a projection using Seo's view. Therefore, it is useful to take projection earlier than talometer and MRI in emergency patients who were doubt posterior cruciate ligament injury in knee joint.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1310-1315
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• 2003

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty (TKA) to yield adequate knee function. The knee joint with TKA is expected ideally to restore the characteristics, however, this is not necessarily true in the clinical cases. In this study the motions of the intact joint and the joint after TKA were investigated numerically using computer simulation. For active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension while it showed only rotation for other flexion angles. Physiologic external rotation of the tibia near full extension was also noted in the analytical model. The analysis of the tibial insert of three different shapes (flat, semicurved, and curved types) demonstrated characteristic rotational and sliding motions as well as different contact forces.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.188-195
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• 2004

Severe osteoarthrosis of the knee joint often requires total knee arthroplasty(TKA) to yield adequate knee function. The knee joint with TKA is expected ideally to restore the characteristics, however, this is not necessarily 1.ue in the clinical cases. In this study the motion of the intact joint and the joint after. TKA were investigated numerically using computer simulation. For active knee extension from 90 degrees of flexion to full extension, the intact knee joint exhibited anterior tibial translation near the full extension and it showed only rotation at other flexion angles. Physiologic external rotation of the tibia near full extension known as screw home movement was also noted in the analytical model. The analysis of the tibial insert of three different shapes (flat, semicurved, and curved types) demonstrated characteristic rotational and sliding motion as well as different contact forces.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.4
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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.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.75-81
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• 2010

Knee osteoarthritis is one of the most prevalent arthritis that weakens the muscles. This study focused on evaluating muscular functionality of knee osteoarthritis subjects. Muscular strengths of muscles around knee and hip joints of middle-aged female subjects aged over 40 suffering from knee osteoarthritis were evaluated by isokinetic dynanometer. Also, relation between the observed muscle imbalance in knee and hip joints and visual analogue scale was investigated. Subjects performed 8-weeks exercise on weakened muscles - particularly on knee extensors and hip abductors - and had their isokinetic muscular functionalities analyzed again. After the 8-weeks exercise, subjects' thigh circumferences were increased, accompanied with muscular strength improvements and decrease in visual analogue scale. Hence we emphasize the importance of exercise for muscular strength enhancement of knee extensors and hip abductors, in rehabilitation programs for knee osteoarthritis.

• The Journal of Korean Physical Therapy
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• v.32 no.1
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• pp.52-57
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• 2020

Purpose: This study compared the muscle activities of the Vastus medialis oblique (VMO) and the Vastus lateralis (VL) at three different knee extension angles: 90°, 135°, and 180° in the sitting position. Methods: Twenty subjects between 20 and 30 years of age participated in the study. A mobile phone application called the Clinometer was used to measure the knee joint angle. Electromyography (EMG) was performed to measure the muscle activities of the VMO and VL muscles during knee isometric extension exercises. The pulling sensor was used to maintain 70% of the maximum strength of the knee extensor continuously in the sitting position. After attaching the EMG sensor, the subjects were asked to perform isometric knee extension exercises randomly among three knee extension angles (90°, 135°, or 180°) in the sitting position. One-way repeated measures analysis of the variance and a Bonferroni post hoc test was used to identify the VMO and VL muscle activity during knee extension angles among 90°, 135°, and 180°. Results: The VMO and VL muscle activities increased with increasing knee extension angle in the sitting position (p<0.01). Conclusions: Knee extension exercise at a 180° angle in the sitting position can be recommended to increase the muscle activity of the VMO and VL muscle activities efficiently.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.4
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• pp.433-442
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• 2012

PURPOSE: This study investigated to correlation between foot and knee posture characteristics in knee osteoarthritis patients. METHODS: The subjects of this study were 103 patients with clinically and radiographically-confirmed knee osteoarthritis was investigated using the quadriceps angle (QA), distance of both knee (DBK), ankle dorsiflexion angle (ADA), navicular drop (ND). One-way ANOVA and Pearson's correlation were used to investigate the correlation between foot and knee posture measurements. All of whom agreed to participate in the study. In order to assure the statistical significance of the results, we used for SPSS ver. 18.0 for windows. RESULTS: The results of this study were as follows : 1) There were statistically significant difference in the correlation between QA and DBK. 2) There were statistically significant difference in the correlation between DBK and ADA. CONCLUSION: According the results of this study, patients with osteoarthritis exhibit more genu varus knee posture. Moreover patients with osteoarthritis were not correlation between foot and knee Posture characteristics.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1473-1474
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• 2008

In the total knee arthroplasty (TKA), kinematic benefic of a mobile-bearing total knee prosthesis is still arguing. Main reasons for implant failure are loosening and polyethylene wear and should be solved with new designs with mob ile bearings. The kinematics of the knee prosthesis also affects the implant failure. Recently, a second generation of p rostheses with a mobile-bearing was developed. The current study aimed to assess the kinematic path of the 2nd generation mobile knee prosthesis compared to the normal knees. Using 3D/2D registration method, CT-derived 3D knee models were fitted to sequential 2D X-ray images during knee flexion. 3D kinematics of the femur and the tibia were analyzed. The 2nd generation mobile-bearing TKA prosthesis (e.motion, Aesculap, Germany) knees showed less external rotation and knee flexion range compared to the normal knee, but the trend of external rotation was similar each other.

• The Journal of Korean Physical Therapy
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• v.33 no.3
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• pp.162-167
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• 2021

Purpose: A hyperextended knee is described as knee pain associated with an impaired knee extensor mechanism. Additionally, a hyperextended knee may involve reduced position sense of the knee joint that decreases the individual's ability to control end-range knee extension movement. The purpose of this study was to investigate the effects of visual biofeedback information for plantar pressure distribution on knee joint angle and lower extremity muscle activities in participants with hyperextended knees. Methods: Twenty-three participants with hyperextended knees were recruited for the study. Surface electromyography signals were recorded for the biceps femoris, rectus femoris, gastrocnemius, and tibialis anterior muscle activities. The plantar pressure distribution was displayed and measured using a pressure distribution measuring plate. Knee joint angle kinematic parameters were recorded using a motion analysis system. The visual biofeedback condition was the point at which the difference between the forefoot and backfoot plantar foot pressure on the monitor was minimized. The Wilcoxon signed-rank test was used to determine the significance between the visual biofeedback condition and the preferred condition. Results: The knee joint angle was significantly decreased in the visual biofeedback condition compared to that in the preferred condition (p<0.05). The rectus femoris and gastrocnemius muscle activities were significantly different between the visual biofeedback and preferred conditions (p<0.05). Conclusion: The results of this study showed that visual biofeedback of information about plantar pressure distribution is effective for correcting hyperextended knees.