• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.7
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• pp.785-790
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• 2011

The goal of this study is to estimate the force acting on the knee joint in the human body by using the Hilltype muscle model based on a musculoskeletal model of the human lower extremity in the sagittal plane. For estimating the force applied, the human leg is modeled using multi-body modeling. This leg model comprises biarticular muscles acting on two joints of the upper and lower limbs, and the muscles include some of the major muscles such as the hamstring. In order to analyze the uncertainty of the applied forces acting on the knee joint, statistical distributions of human body, leg part, parameters are required and to obtain the parameter's statistical characteristic of the part sample survey method is employed. Finally, by using the sensitivity information of the parameters, the force acting on the knee joint can be estimated.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.224-231
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• 2020

The purpose of this study was to analyze the effect of ankle joint taping treatment on lower extremity joint and center of pressure(COP) factors during the Uchi-mata. Twenty college judo athletes (age, 20.9 ± 0.8 years; height, 168.6 ± 7.4cm; weight, 73.5 ± 11.6kg; body mass index, 25.7 ± 2.6kg/㎡) participated, and two types before and after ankle joint taping treatment when the during the Uchi-mata was exhibited under conditions, the angle and COP factors of the support leg joints were analyzed to show the following results. At the time of E2 (t = 2.411, p = .027) E4 (t = 2.388, p = .029), the ankle joint angle was statistically less after the treatment than before the taping treatment, and E2 (t = -2.343, p = .032) At E3 (t = -4.531, p = .000), the angle of the hip joint was statistically large. And after the ankle joint taping treatment, the medial/lateral COP movement after the ankle joint taping treatment was statistically large in the P3 phase of throwing the opponent (t = 2.670, p = .016), and the anterior/posterior COP movement showed a statistically small number in the P1 phase where the opponent was tilted (t = 2.846, p = .011). Therefore, it was suggested that judo athletes who use thighs as a special technique should be used considering the movement function of the support joint and the range of movement of the COP caused by tapping of the ankle joint.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.137-148
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• 2006

The purpose of this study was to compare muscle activity in the lower extremity during walking wearing jogging and roller shoes. Twelve male middle school students (age: 15.0 yrs, height 173.7 cm, weight 587.7 N) who have no known musculoskeletal disorders were recruited as the subjects. Seven pairs of surface electrodes (QEMG8, Laxtha Korea, gain = 1,000, input impedance >$1012{\Omega}$, CMMR >100 dB) were attached to the right-hand side of the body to monitor the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), tibialis anterior (TA), and medial (GM) and lateral gastrocnemius (GL) while subjects walked wearing roller and jogging shoes in random order at a speed of 1.1 m/s. An event sync unit with a bright LED light was used to synchronize the video and EMG recordings. EMG data were filtered using a 10 Hz to 350 Hz Butterworth band-passdigital filter and further normalized to the respective maximum voluntary isometric contraction EMG levels. For each trial being analyzed, five critical instants and four phases were identified from the recording. Averaged IEMG and peak IEMG were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p<.05). The VM, TA, BF, and GM activities during the initial double limb stance and the initial single limb stance reduced significantly when going from jogging shoe to roller shoe condition. The decrease in EMG levels in those muscles indicated that the subjects locked the ankle and knee joints in an awkward fashion to compensate for the imbalance. Muscle activity in the GM for the roller shoe condition was significantly greater than the corresponding value for the jogging shoe condition during the terminal double limb stance and the terminal single limb stance. Because the subjects tried to keep their upper body weight in front of the hip to prevent falling backward, the GM activity for the roller shoe condition increased. It seems that there are differences in muscle activity between roller shoe and jogging shoe conditions. The differences in EMG pattern may be caused primarily by the altered position of ankle, knee, and center of mass throughout the walking cycle. Future studies should examine joint kinematics during walking with roller shoes.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.399-406
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• 2009

The purpose of this study was to compare the effect of wearing roller shoes and jogging shoes on kinematic characteristics in lower extremity during walking. Eight male middle school students(age: $15.0{\pm}0.0^{\circ}$ yrs, height $175.9{\pm}6.6cm$, weight: $616.3{\pm}84.9$ N) who have no musculoskeletal disorder were recruited as the subjects. Temporal parameters, step length, stride length, center of mass, velocity of CM, angle of segment, angular velocity and range of motion were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions(p < .05). The results showed that stride length and velocity of CM in wearing roller shoes were significantly less than those found in wearing jogging shoes. These indicated that walking patterns may be changed by different shoe conditions and unstable braking condition because of wheel. Angle of ankle joint at LHC1 and LHC2 in wearing roller shoes was greater than the corresponding value for wearing jogging shoes. It seems that the ankle joints are locked in an awkward fashion at the heel contact to compensate for imbalance. Otherwise, dorsi flexion was not produced at the heel contact point in wearing roller shoes.

• Journal of the Korea Convergence Society
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• v.10 no.9
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• pp.63-68
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• 2019

The purpose of this study was to investigate the effect of hyper-extended knee and asymmetric standing posture on knee joint position and lower extremity muscle activity. Thirty-three voluntary participants participated and included sixty legs in the study. The sixty legs were divided into two groups: hyper-extended knee and normal group. The muscle activity and knee extension angle were measured. In the asymmetric standing posture, the knee joint extension angle and the muscle activity of the gastrocnemius were statistically significant between the normal group and the hyper-extended knee group. Based on the results, we confirmed that the asymmetric standing posture increases the hyper-extended knee. Therefore, it will contribute to the establishment of therapeutic guide for the subjects with hyper-extended knee to maintain the symmetrical standing posture, and future studies need to be conducted including the effects of the hip joint and ankle joints.

• 한국체육학회지인문사회과학편
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• v.57 no.3
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• pp.345-356
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• 2018

Objective: The purpose of this study was to investigate the local stability of the lower extremity joints and muscle activation patterns of the lower extremity during walking between falling and non-falling group in the elderly women. Method: Forty women, heel strikers, were recruited for this study. Twenty subjects (age:72.55±5.42yrs; height:154.40±4.26cm; mass:57.40±6.21kg; preference walking speed:0.52±0.17m/s; fall frequency=1.70±1.26 times) had a history falls(fall group) within two years and Twenty subjects (71.90±2..90yrs; height:155.28±4.73cm; mass:56.70±5.241kg; preference walking speed: 0.56±0.13m/s) had no history falls(non-fall group). While they were walking on a instrumented treadmill at their preference speed for a long while, kinematic and EMG signals were obtained using 3-D motion capture and wireless EMG electrodes, respectively. Local stability of the ankle and knee joint were calculated using Lyapunov Exponent (LyE) and muscles activation and their co-contraction index were also quantified. Hypotheses were tested using one-way ANOVA and Mann-Whitey. Spearman rank was also used to determine the correlation coefficients between variables. Level of significance was set at p<.05. Results: Local stability in the knee joint adduction-abduction was significantly greater in fall group than non-fall group(p<.05). Activation of anterior tibials that acts on the foot segment dorsal flexion was greater in non-fall group than fall group(p<.05). CI between gastrocnemius and anterior tibials was found to be significantly different between two groups(p<.05). In addition, there was significant correlation between CI of the leg and LyE of the ankle joint flexion-extention in the fall group(p<.05). Conclusion: In conclusion, muscles that act on the knee joint abduction-adduction as well as gastrocnemius and anterior tibials that act on the ankle joint flexion-extention need to be strengthened to prevent from potential fall during walking.

• Physical Therapy Korea
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• v.27 no.2
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• pp.133-139
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• 2020

Background: The gastrocnemius (GCM) is one of the lower extremity muscles that tend to tighten easily. GCM tightness results in limited ankle dorsi-flexion (DF), especially when the knee joint is fully extended. Joint flexibility is determined by the morphological and physiological characteristics of joints, muscles, tendons, and ligaments. Impaired joint flexibility can be attributed to increased susceptibility to muscle injury. High-frequency diathermy is clinically used to reduce pain and muscle tightness and to improve limited range of motion. Objects: This study aimed to investigate the immediate effects of high-frequency therapy in subjects with GCM tightness. Methods: The study was designed as a one-group before-after trial. The subjects included 28 volunteers with GCM tightness (an active ankle DF angle of less than 12°) without any known neurological and musculoskeletal pathologies in the ankle and calf areas. WINBACK Transfer Electrode Capacitive and Resistive Therapy equipment was used to apply high-frequency therapy to the subjects' GCMs for 10-15 minutes. The pennation angle and the fascicle length of the GCM were measured using ultrasonography. The flexibility of the ankle joint, peak torque to the passive ankle DF (Biodex), and soft tissue stiffness (MyotonPRO) were also measured. Results: The pennation angle was significantly decreased following the treatment; however, no significant difference in the fascicle length was found (p < 0.05). The flexibility was significantly increased and both the passive peak torque to passive ankle DF and the soft tissue stiffness significantly decreased (p < 0.05). Conclusion: High-frequency therapy is immediately effective for improving the muscle's architectural properties and functional factors in subjects with GCM tightness. Further longitudinal clinical studies are required to investigate the long-term effects of high-frequency therapy on subjects with GCM tightness from various causes.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.2 no.1
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• pp.99-114
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• 2007

Objectives : The purpose of this study was to introduce the Chuna Manual Therapy (CMT) using Bong (a type of stick which is called 'bong') as a part of Oriental Medicine. Methods : We searched several traditional methods of CMT using Bong, either individual contact to specialist of CMT using Bong or referred to publications, and summarized briefly for introduction. Authors also made a comparative study between existing CMT and CMT using the bong. Results & Conclusions : The indications of Bong CMT are regarded as acute or chronic pain syndrome, whiplash associated disorders, facet syndrome, vertebral misalignment, chronic fatigue syndrome, obesity and also lower extremity length difference caused by malalignment of vertebrae and pelvic bone. The Meridian Muscle Therapy by pressing down using the Bong can be carried out on the imbalances of the muscle by shortening and lengthening contraction. CMT with Bong is considered more effective than other existing CMT in terms of effectiveness. In the case of pelvic correction which needs a tremendous amount of force, it can reduce the force required effectively. This fact can be inferred by the theory of composition and decomposition of force during the transmission of power. We can perform Bong CMT feeling less fatigued subsequently than general CMT. Pressing down with flexed fingers to grip bong acts on the contraction of flexor digiti and extensor digiti muscle, this protects the $doctor^{\circ}{\emptyset}s$ wrist joints from injury. The bong which acts as a tool between the doctor and the patient, while being given treatment, absorbs and spreads out the direct impact from the patient to the doctor. CMT with Bong is able to apply to both existing massage therapies with the hand. The bong appliance can be used in all applications, particularly, but not limited to; Orthopedic and Manual Correction Therapy, Meridian Muscle Pressing, Exercise Therapy, and Meridian Point Manual Pressing Therapy. CMT with Bong belongs to the category of oriental rehabilitation and Chuna manual medicine.

• Archives of Reconstructive Microsurgery
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• v.7 no.2
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• pp.165-174
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• 1998

Large soft tissue defect of the ankle and foot can present a difficult reconstructive problem to the surgeon. Local musculocutaneous, local fasciocutaneous or free flap is usually the first choice for providing soft tissue coverage. However, in certain situations, local flaps from the same leg and free flap may not be suitable. These include extensive soft tissue injury, where no suitable recipient vessels can be found, previous local fasciocutaneous flap or free flap failure. In such cases, we have utilized the septocutaneous(fasciocutaneous) branch flap of posterior tibial artery from the opposite healthy limb. We present 5 cases of cross leg flaps, which have been modernized with current understanding of vascular anatomy and current fixation technology. All cross leg flaps were based on the axial blood supply of the fasciocutanous branch of the posterior tibial artery. Cross-clamping with bowel clamp was used to create intermittent periods of ischemia. Adjacent lower extremity joints were exercised during the periods of attachment. The results have been quite encouraging. We conclude that the cross leg flap using septocutaneous flap and cast immobilization can be successfully and expeditiously used to cover defects of the ante and foot.

• Korean Journal of Applied Biomechanics
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• v.23 no.1
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• pp.85-90
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• 2013

Efficient gait is compensate for a lack of exercise, but the wrong walking can cause disease that joints, muscles, brain and body structure(Scott & Winter, 1990). Also many researchers has been studied gait of positive mechanism using analytical methods kinetic, kinematic. This study is to identify nature of knee adduction moment, depending on different foot progression angle and the movement of rotation of pelvis and body. Health study subject conducted intended walking with three different angles. The subjects of this study classified three types of walking; walk erect, pigeon-toed walk and an out-toed gait. Ten university students of K without previous operation and disease record selected for this study. For accuracy of this study, three types of walking carried out five times with 3D image analysis and using analysis of ground reaction force to analyze nature of knee adduction moment and the movement of rotation of pelvis and body. Firstly, the HC(heel contact) section value of intended walk erect, pigeon-toed walk and an out-toed gait was not shown statistically significant difference but TO(toe off) section value was shown that the pigeon-toed walk statistically significant. The value of pigeon-toed walk was smallest knee adduction moment(p< 0.005). Secondly, X axis was the change of rotation movement body and pelvis when walk erect, pigeon-toed walk and an out-toed gait. Shown statistically Y axis was not shown statistically significant but Z axis statistically significant(p<0.05). These result show the significant differences on TO section when walking moment reaches HC, it decides the walking types and rotates the foot.