• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.239-245
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• 2007

The purpose of this study was to compare the electromyography signal's power spectrum mean and median tendencies appearing in the lower extremity during walking while wearing roller shoes. 9 male subjects volunteered who have no experience riding inline-skate or roller-skate, and have no record of musculoskeletal disorder. Subjects walked on treadmill twice for an hour (Once a week, one trial with the roller on and the other without roller, Walking velocity = 1.39 m/s). Electromyography was measured every 15 minute (0, 15, 30, 45, 60 minutes). Surface electrode sticked muscle at rectus femoris(R.F.), vastus lateralis(V.L.), vastus medialis(V.M.), biceps femoris(B.F.), tibialis anterior(T.A.), gastrocnemius lateralis(G.L.), gastrocnemius medialis(G.M.). At Rectus femoris, Vastus Lateralis, Vastus medialis, and Biceps femoris showed no statistically significant decrease of median frequency or mean edge frequency as time passes. Also, between two treatments (wearing the roller shoes vs not wearing the roller shoes), no statistically significant difference. After 60 minutes, mean edge frequency showed statistically significant decrease at tibalis anterior and after 45 minutes, mean edge frequency showed statistically significant decrease compared to wearing roller shoes without the wheels at gastrocnemius lateralis. At gastrocnemius medialis after 30 minutes, median frequency showed statistically significant decrease, and showed statistically significant difference compared to the control group. Wearing the roller shoes with wheels for a long time resulted in statistically significant decrease of mean edge frequency and median frequency in lower extremity, especially in shank muscles. Increase of wearing time of roller shoes and walking on a bumpy road wearing roller shoes with wheels result fatigue and thus, danger of injury.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.2
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• pp.39-46
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• 2015

Background: The purpose of this study was to investigate the influence of short-term treadmill walking with high-heeled shoes on electromyography activities of the medial gastrocnemius, lateral gastrocnemius and tibialis anterior in healthy young females. Methods: Fifteen healthy females were recruited for this study. To measure muscle activation, the subjects were asked in random order to walk on a treadmill using either high-heeled shoes or barefoot conditions. The shoe heel height for high-heeled walking was 7 cm. The walking speed on the treadmill was 4 km/h, and the inclination rate of the treadmill was 10%. The subjects performed treadmill walking in the barefoot and high-heeled walking conditions for 5 minutes. Electromyography data were collected from the tibialis anterior, medial gastrocnemius, lateral gastrocnemius, and soleus on both firm and foam surfaces and during eyes-open and-closed conditions while standing. Results: Tibialis anterior activity was significantly different before and after the walking task while standing on a foam surface with eyes closed (p<.05). Conclusion: This finding suggests that the activity of the tibialis anterior may be lowered after high-heeled walking. Therefore, high-heeled shoes contribute to harmful effects at the ankle joints, increasing the risks of falling and musculoskeletal injury.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.115-122
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• 2011

Recently, we have proposed a hypothesis that spinal structures have a stress sensor driving feedback mechanism, In the human spine, spinal structure could react to modify muscular action in such a way so as to equalize stress at the disc, therefore reduce the risk of injury, In this analysis, abdominal muscle and abdominal pressure, which were not included in the previous study, were added to identify those effects in spine stability during upright stance posture for the case where the intervertebral disc plays the role of mechanoreceptor, The musculoskeletal FE model was consisted with detailed whole lumbar spine, pelvis, sacrum, coccyx and simplified trunk model. Muscle architecture with 46 local muscles containing paraspinal muscle and 6 rectus abdominal muscles were assigned according to the acting directions. The magnitude of 4kPa was considered for abdominal pressure. Minimization of the nucleus pressure deviation and annulus fiber average tension stress deviation was chosen for cost function. Developed model provide nice coincidence with in-vivo measurement (nucleus pressure). Analysis was conducted according to existence of co-activation of abdominal muscle and abdominal pressure. Antagonistic activity of abdominal muscle produced stability of spinal column with relatively small amount of total muscle force. In contrast to the abdominal muscle, effect of abdominal pressure was not clear that was partly depending on the assumption of constant abdominal pressure.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.3
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• pp.49-54
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• 2016

PURPOSE: This study was implemented to measure the muscle activity of muscles surrounding shoulder during push-up exercise according to the slope angle. METHODS: This study has research subject consisting of 25 normal male adults without neurologic or musculoskeletal injury in shoulder part. EMG was used as a tool for measuring muscle activity and four muscles including upper trapezius (UT), middle trapezius (MT), Lower Trapezius (LT), and Serratus Anterior (SA) were chosen for measuring the muscle activity of muscles surrounding shoulder. Tilting table slope was set at $0^{\circ}$, $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$ and push-up motion was performed three time for each case to use the average value. The measured value was used after generalization process to create %RVC value where the measured value was standardized by using $0^{\circ}$ as a standard. RESULTS: There was a difference of muscle activity according to the tilting table slope during push-up exercise. In UT, MT, and SA, there was no significant $0^{\circ}$ and $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$. But there was significant $30^{\circ}$ and $45^{\circ}$. LT was significant difference between $45^{\circ}$ and $60^{\circ}$ (p<.05). CONCLUSION: There are cases where push-up exercise should be selectively implemented due to shoulder problems. According to this results between $0^{\circ}$ and $30^{\circ}$, push up will be able to more effectively exercise. Applying proper angle of tilting table for push-up to patients who have difficulties in performing motions along with physical consumption can deliver effective and easy exercise program.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.88-93
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• 1996

Neurilemmomas are the most common benign tumor of the peripheral nerve trunks, and arises from the cells in the sheath of Schwann. Neurilemmomas are well encapsulated and may be separated easily from surrounding tissue and lie completely within a larger nerve trunk, with bundles of neurofibrils spread out over the surface of the tumor. A careful dissection and retraction of the nerve bundles will allow the tumor to be enucleated from the parent nerve without any significant interference with the function of the nerve. Resection of the involved nerve is seldom necessary and should be avoided if at all possible. Our aim in microscopic excision of neurilemmoma of extremities is to reduce any disturbance of the intact neurofibrils of the parent nerve. Thirteen cases of neurilimmomas were treated by microscopic excision at the Department of Orthopaedic Surgery, Korea University Hospital between January 1990 and March 1995. The results was as follows ; 1. The average age at surgical intervention was 40.1 years. Cases in fourth and fifth decades predominated. 2. In their anatomical distribution, 8 cases were in the upper extremity and 5 cases in the lower extremity. 11 cases were on the flexor surface. 3. On the operative field, all the tumors were well encapsulated, however 1 case of 13 was adherent to the periosteum of fibula. 4. In all cases, the tumor were enucleated from the parent nerve without any injury to nerve under high-power magnification, preserving individual fascicles, and sensory and motor function.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.39-46
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• 2017

PURPOSE: The effectiveness of the stretching to increase the range of motion of the joint, reduce the risk of injury, enhance athletic performance or decrease post exercise muscle soreness. This study was to compare the effect of the stretching method applied on the shortened hamstring muscle for flexibility, strength, pressure pain threshold value and muscle tone. METHODS: This study is a two-group pretest- posttest design. Fifty-four healthy young adults were randomly assigned to a vibration-assisted stretching group (VASG, n=27) or a static stretching group (SSG, n=27). Participants performed each stretch in 4 sets of 30 seconds each. A 30-second break time was provided between the sets. The range of motion, strength, pressure pain threshold values and muscle tone of the hamstring muscle were measured to compare the effects of the stretching methods. RESULTS: Both the VASG and the SSG participants showed significant improvement in the range of motion and strength (p<.05); however, the increase in the VASG was significantly higher than that in the SSG (p<.05). The pressure pain threshold values and muscle tone were significantly decreased only in the VASG (p<.05). CONCLUSION: These findings indicate that vibration-supported stretching is an effective intervention for people with hamstring shortening, with high pain level and muscle tone decrease.

• Journal of Chest Surgery
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• v.46 no.2
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• pp.93-97
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• 2013

Background: Minimally invasive cardiac surgery has emerged as an alternative to conventional open surgery. This report reviews our experience with atrial septal defect using the da VinciTM surgical robot system. Materials and Methods: This retrospective study included 50 consecutive patients who underwent atrial septal defect repair using the da VinciTM surgical robot system between October 2007 and May 2011. Among these, 13 patients (26%) were approached through a totally endoscopic approach and the others by mini-thoracotomy. Nineteen patients had concomitant procedures including tricuspid annuloplasty (n=10), mitral valvuloplasty (n=9), and maze procedure (n=4). The mean follow-up duration was $16.9{\pm}10.4$ months. Results: No remnant interatrial shunt was detected by intraoperative or postoperative echocardiography. The atrial septal defects were mainly repaired by Gore-Tex patch closure (80%). There was no operative mortality or serious surgical complications. The aortic cross clamping time and cardiopulmonary bypass time were $74.1{\pm}32.2$ and $157.6{\pm}49.7$ minutes, respectively. The postoperative hospital stay was $5.5{\pm}3.3$ days. Conclusion: The atrial septal defect repair with concomitant procedures like mitral valve repair or tricuspid valve repair using the da VinciTM system is a feasible method. In addition, in selected patients, complete port access can be helpful for better cosmetic results and less musculoskeletal injury.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.167-174
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• 2008

The application of tape is being widely used for treatment of the musculoskeletal disorders and injury prevention. The techniques of the tape application has been relied on empirical evidence in preference to the neurophysiological evidence. Thus, the mechanism of taping has to be elucidated further. In this study, we assessed the effect of the elastic and non-elastic tape upon the gastrocnemius ${\alpha}$-motor neuron excitability using the gastrocnemius H-reflex. The amplitude of the M-wave and H-reflex were measured across three conditions: before tape application, with tape and with the tape removed. No significant changes of the excitability of the ${\alpha}$-motor neuron were obtained across three condition, either in the elastic and non-elastic tape. This results were quite different with other recent studies, which needs to be explored further.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.347-355
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• 2013

The purpose of this study was to determine the biomechanical effect of wearing the mouthguard on the lower limb during drop landing. Nine male university students who have no musculoskeletal disorder were recruited as the subjects. Linear velocity, angular velocity, vertical GRF, loading rate, joint moment, and lower extremity muscle activity were determined for each subject. For each dependent variable, paired t-test was performed to test if significant difference existed between with mouthguard (WM) and without mouthguard (WOM) conditions (p<.05). The results showed that linear velocity, angular velocity, vertical GRF and loading rate were no significant difference between the two groups. The inversion moment of the ankle joint was increased in WM compared to WOM. Average IEMG values from BF, TA, and LG in WM were significantly greater than corresponding values in WOM during IP phase. This indicates that wearing mouthguard played a vital role in muscle tuning for maintaining joint stability of the lower limb and preventing injury.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.2
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• pp.52-65
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• 2006

Sling exercises therapy can speak as appliable comprehensive exercises therapy technique efficiently in general exercise field for injured worker's rehabilitation process and health improvement patient or athlete, injury or disease that have pain or dysfunction to neuromuscular system using that shake. At 1990 an early stage, because physical therapist and doctors of medical treatment developed country norway of north europe cooperate sling exercises therapy's concept trend spreading worldwide establishing theory newly based on scientific basic be. Musculoskeletal system, old man and young child's nervous system injurer's treatment and exercise and industry worker's rehabilitation process, athlete's rehabilitation etc. several fields introduced in early 2000s to Korea apply. Sling exercises therapy neuromuscular system disease continuous abatement as general concept of active exercise and treatment that use sling exercises equipment by purpose know can. This review article wishes to introduce about neuromuscular activation, "Neurac" technique that can speak as step developed more concept based on application principle etc, of basic sling exercises effort's change by suspension point's change that is concept, stability exercises principle, open kinetic chain exercises and closed kinetic chain exercises. Arranged about Plateau potential's characteristic and working mechanism and Neurac technique's application method that can say as Neurac technique's neuro-physiologic base, and presented treatment method of lumbar part disease and cervical part, shoulder joint part disease to application example. Because plateau potential forward player that induce using Neurac technique in part muscles that act role that keep spine surrounding stability in this article keeps muscle's contraction continuously, between global and local muscles, presented several study findings that can cause affirmative change in insufficient muscle adjustment state such as imbalance of muscles' action order. Expect that case studies that use this Neurac technique here after consist continuously.