• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.131-139
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• 2013

Naejirgi is one of the fastest, most forceful and most often being used kicks in Taekkyon games, The purpose of this study was to investigate kinetic factors on two types of Naejirgi kick, one of which uses knee bending of supporting leg and the other uses little it. 12 taekkyoners (11 males and one female) who are the students of Y University participated in this study. They have been practicing on Taekkyon for five years or more. Positions of CoM, the elapsed time of each phase, vertical ground reaction forces, joint moments and impulses of supporting leg were analyzed for this study. The results were as follows; in Naejirgi with knee bending of supporting leg than without knee bending of supporting leg, the vertical motion range of whole body CoM was larger during phase 2 and 3, the elapsed time of phase 4 were longer, players stayed longer in the nearest location to opponent, during phase 4 the vertical ground reaction forces of supporting foot were larger, and joint extension moments and angular impulses of supporting leg (especially knee) were larger. In conclusion supporting knee bending is not a useful strategy for Naejirgi, because players stay longer in the nearest position to opponent and consumed more muscle force and energy for producing the vertical momentum which is unnecessary for pushing down the opponent.

• 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.

• PNF and Movement
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• v.22 no.2
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• pp.171-180
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• 2024

Purpose: This study aimed to investigate the use of insoles in patients with temporomandibular joint disorders to assess the function and changes in pain when walking in daily life. Methods: Sixty-five patients with temporomandibular joint disorder, were selected, with 34 assigned to the control group and 31 to the experimental group. The control group walked more than 7,000 steps per day in their daily life, while the experimental group wore insoles and was instructed to take at least 7,000 steps every day. To evaluate the effect on temporomandibular joint pain, steady-state pain, maximum mouth opening, average pain, and the most severe pain were measured before and after the experiment. In addition, to determine function, mouth opening in a comfortable state, mouth opening pain, and the point of sound and the maximum degree of mouth opening were evaluated before and after the experiment. Results: After the experiment, pain, mouth opening, and sound points showed significant differences compared to the control group. However, there was no significant difference in the maximum mouth opening range. Conclusion: The application of air insoles to patients with temporomandibular joint disorder confirmed the function of the temporomandibular joint and its positive effects on pain.

• Journal of the Korean Arthroscopy Society
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• v.4 no.1
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• pp.25-31
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• 2000

Introduction : This study compared the clinical results with biceps rerouting fer the isolated posterolateral instability (PLI) and for the PLI combined with PCL injuries. Methods : 21 cases of isolated PLI (group I) and 25 cases of PLI combined with PCL rupture were included in the study. The PLI was reconstructed by modified biceps femoris rerouting technique with PCL reconstructions performed prior to the PLI correction in cases of combined injury The clinical results were reviewed and analyzed. Results : Pre-operatively positive reverse pivot shift test turned negative in 43 cases post-operatively. Increased preoperative external rotation thigh foot angle (ERTFA) showed significant differences between the two groups and all fell within normal limits post-operatively At a mean follow-up of 40.3 months, the average Lysholm knee score and. The Hospital for Special Surgery Knee Ligament Score for group I and group II revealed above 90 points without statistically significant difference between the groups. 3 cases of tenodesis failure developed and re-operation was performed. Discussion and Conclusion : The advantages of modified Clancy technique include reduced surgical damages to the iliotibial band and fixation of the biceps tendon at the isometric position. The modified biceps rerouting technique is recommended for the reconstruction of both isolated and combined PLI except in patients with severe damages at the attachment of biceps tendon.

• Journal of Haehwa Medicine
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• v.22 no.1
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• pp.23-36
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• 2013

J$\bar{i}$n ji$\acute{e}$(根結) has been recognized as one of a meridian pathway. If you want to study a defense qi(衛氣) and nutrient qi(營氣)'s nature, function and operation, you could find a relationship of J$\bar{i}$n ji$\acute{e}$(根結) and the defense qi(衛氣). We proposed that, especially, J$\bar{i}$n ji$\acute{e}$(根結) has got a close relationship with a operation of the defense qi(衛氣). The ji$\acute{e}$(結) of three yang(三陽) located in ears and eyes, that are a starting point of the defense qi(衛氣) operation in the daytime and a one of five sense organs(五官). Gin, Liu, Zou and Ru (根, 溜, 注, 入) of the three yang(三陽) distinguished between the three yang(三陽) in the extremities. and in the symptoms of a disease of the three yang(三陽) on the bolt - leaf - hanges(關闔樞) theory, Greater yang(太陽) is related to the skin and flesh, Yang brightness(陽明) is related to the flesh and Lesser yang(少陽) is related to the muscle or bone. These skin, flesh, muscle and bone belonged to the five bodies(五體). The five bodies(五體) have relationship with the defense qi(衛氣)'s operation and function part. The ji$\acute{e}$(結) of three yin(三陰) located in neck, chest and abdomen. If we could catched the concepts on the ji$\acute{e}$(結) of three yin(三陰) and The Gin, Liu, Zou, Ru and ji$\acute{e}$(根, 溜, 注, 入, 結) position of three yang(三陽) altogether, we could suggested the theory of the entire area completed in the surface of body. so the defense qi(衛氣)'s protecting function of the whole body surface is achieved. In the symptoms of a disease of the three yin(三陰)'s the bolt - leaf - hanges(關闔樞) theory, greater yin(太陰) and reverting yin(厥陰)'s symptoms indicates the defense qi(衛氣)'s main action of a chest and abdomen. And lesser yin(少陰)' symptoms is about a vessle, that is not to mention on the five bodies(五體) of the three yang(三陽)'s symptoms, so here is mentioned the relationship of the defense qi(衛氣) and the five bodies(五體) strengthened. In the "J$\bar{i}$n ji$\acute{e}$ chapter(根結編) of Lin Shu(靈樞)", as the meridians of the foot (足經) was described, except the meridians of the hand(手經), it is reasonable to infer that the defense qi (衛氣) is relevant to the meridians of the foot(足經) than the meridians of the hand(手經).

• Journal of Acupuncture Research
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• v.33 no.2
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• pp.181-187
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• 2016

Objectives : The purpose of this report is to introduce a case of osteochondral lesions of the left talus caused by ankle sprain and suggest complex traditional Korean medical care with warm needling therapy as a possible method of conservative treatment. Methods : A 20-year-old male with osteochondral lesions of the left talus complaining of ankle pain and restricted range of movement was treated mainly with warm needling therapy and other combined Korean medicine therapy from January 5, 2015 to January 12, 2015. Improvements of symptoms were measured by American Orthopaedic Foot & Ankle Society Score (AOFAS Score), Visual Analog Scale (VAS) and Range of movement (ROM). Results : During 8 days of treatment, the patient showed gradual improvement in AOFAS score, VAS at rest and at weight bearing position, as well as ROM of the ankle. Conclusion : According to the result, warm needling therapy is a possible conservative treatment for osteochondral lesions of the talus. Further studies are needed regarding possible longterm effects.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.1-10
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• 2015

Objective : The purpose of this study was to find some kinetic variable's relationships between personal records and low records in female high jump. Methods : Collected data of the subjects(N=8, ages: $25.5{\pm}1.85$, height: $173{\pm}5.83$, mass: $54.75{\pm}6.36$ personal record: $1.71{\pm}0.04$, low record: $1.62{\pm}0.03$) were used for the last three strides and take-off phase. Five video cameras set in 30frames/s were used for recording. After digitizing motion, the Direct Linear Transformation(DLT) technique was employed to obtain 3-D position coordinates. The kinematic and kinetic factors of distance, velocity, angle, impulse, jerk variables were calculated. A paired t-test was applied for the difference of variables between personal records and lower records and for correlation with performances and variables. The significance level was accepted at p<.05. Results : There was no relationship between pattern of stride and performance. However, rate of change of velocity was related with cental of mass height(CMH) at peak point(PP). Knee, hip, backward lean, foot plant, approach and take off angle showed no difference between best record and low record. Vertical impulse momentum also showed no difference between performances. Conclusion : According to a t-test result, there were significant differences in CMH at PP and jerk at touch down between best record and low record.

• Physical Therapy Korea
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• v.27 no.2
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• pp.126-132
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• 2020

Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a co-contraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.3 s.309
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• pp.16-24
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• 2006

In this paper, fault-tolerant gait planning of a hexapod robot for walking over irregular terrain is presented. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. Based on the previously proposed fault-tolerant tripod gait for walking over even terrain, fault-tolerant follow-the-leader(FTL) gaits are proposed for a hexapod robot with a failed leg to be able to walk over two-dimensional rough terrain, maintaining static stability and fault tolerance. The proposed FTL gait can have maximum stride length for a given foot position of a failed leg, and yields better ditch crossing ability than the previously developed gaits. The applicability of the proposed FTL gait is verified by using computer graphics simulations.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.1
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• pp.57-62
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• 2014

Most analytical models of the human body have focused on conscious responses. A patellar tendon reflex, a representative example of spinal reflexes, occurs without a neural command. Muscle forces and activation of the quadriceps femoris muscles in healthy adults during patellar tendon reflex are identified in this study. The model is assumed to move in the sagittal plane, and the thigh and the trunk are assumed to be fixed in a sitting position so that the shank can move similar to a pendulum. The knee joint is modeled as a revolute joint, and the ankle joint is modeled as a fixed joint so that the shank and the foot can be regarded as one rigid body. Muscle forces are calculated following the inverse dynamic approach. Kinematic data obtained from an experiment (Mamizuka, 2007) are used as input data. Muscle activations are identified using a Hill-type muscle model. The obtained simulation results are compared with experimental results for validating the model and the underlying assumptions.