• Title/Summary/Keyword: muscle shortening

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Muscle Model including Muscle Fatigue Dynamics of Stimulated Skeletal Muscle (전기자극에 의한 골격근의 근육피로를 고려한 근육모델)

  • Lim, Jong-Kwang;Nam, Moon-Hyon
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.11
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    • pp.1476-1478
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    • 1999
  • A musculotendon model is proposed to predict muscle force during muscle fatigue due to the continuous functional electrical stimulation(FES). Muscle fatigue dynamics can be modeled as the electrical admittance of muscle fibers and included in activation dynamics based on the{{{{ { Ca}^{2+ } }}}} kinetics. The admittance depends on the fatigue variable that monotonically increase or decrease if electrical pulse exists or not, and on the stimulation parameters and the number of applied pulses. In the response of the change in activation the normalized Hill-type contraction dynamics connected with activation dynamics decline the muscle shortening velocity and thus its force under muscle fatigue. The computer simulation shows that the proposed model can express the muscle fatigue and its recovery without changing any stimulation parameters.

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Septal Approach on Upper Blepharoplasty in Elderly Person (노화된 안검에서 상안검 교정술 시 안와 격막 접근법)

  • Oh, Eui-Sun;Yun, In-Sik;Park, Beyoung-Yun
    • Archives of Plastic Surgery
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    • v.37 no.5
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    • pp.659-666
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    • 2010
  • Purpose: Blepharoplasty plays a vital role in facial rejuvenation. Aging eyelids are the result of relaxation of lid structures as the skin, the orbicularis muscle, and mainly the septum, with subsequent protrusion or pseudoherniation of intraorbital fat contents. Traditional blepharoplasty has often involved the excision of excessive lax skin and muscle and removal of fat, leaving the eyelid unnatural and even causing the brow ptosis. The authors propose the septal approach through which the amount of skin excision can be decreased and solid fixation can be achieved in the upper blepharoplasty. Methods: From November 2007 to February 2010, total of 15 patients underwent upper blepharoplasty with septal approach. In 9 patients, orbital septum anchored into the orbital periosteum only. But in 6 patients, the attenuated septum was strengthened through shortening and fixing into orbital periosteum with non-absorbable suture. Results: Pleasing results were obtained from most of the patients. But one patient who had septum anchoring procedure complained of slight undercorrection, therefore secondary operation with septum shortening procedure was followed. Conclusion: We found that the method using orbital septum fixation into orbital periosteum has several advantages: less amount of skin excision, less recurrence rate, and more natural appearance. And the results were reliable and satisfactory.

Effects of Carcass Treatments on Sarcomere Length, Drip Loss and Protein Solubility of Porcine Longissimus Muscle (사후 도체처리가 돈육 등심근의 근절길이와 육즙감량 및 단백질 용해성에 미치는 영향)

  • 강근호;이정일;주선태;박구부
    • Food Science of Animal Resources
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    • v.21 no.3
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    • pp.192-199
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    • 2001
  • The objective of this study was to investigate the effects of hot- and cold-boning on sarcomere length, drip loss and protein solubility of post-rigor porcine longissimus muscle. A total of ten pigs(borrow, 100$\pm$5 kg) were randomly selected at a commercial plant and the carcasses were split in half after slaughter. The longissimus muscle of the left side was dissected and chilled at 0$^{\circ}C$ after trimming of subcutaneous fat whereas the right side carcasses were served for cold-boning after chilling for 24 hrs. The temperature, pH and sarcomere length of porcine longissimus muscle were measured at postmortem 1, 3, 6, 12 and 24 hours. Drip loss, cooking loss, Minolta L*a*b*, shear force and protein solubility were measured at postmortem 24 hrs. The pH of cold-boning samples was rapidly decreased whereas temperature and sarcomere length of hot-boning samples were rapidly decreased during 24 hrs of chilling. Hot-boning muscles showed significantly (P<0.05) higher pHu and shorter sarcomere compared with cold boning muscles because of cold shortening. However, there were no significant differences in drip loss, cooking loss and shear force value between hot- and cold boned samples. The samples of hot-boning showed lower Minolta L* value and higher sarcoplasmic protein solubility compared with cold boned samples. These results suggest that the pale color changing of porcine longissimus muscle could be inhibited by hot-boning due to rapid chilling of the muscle although sarcomere length could be shortened because of cold shortening. Also these results show that hot-boning of porcine carcass could have a high protein solubility without negative effects of drip loss or tenderness of porcine longissimus muscle.

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Positional Release Muscle Energy Technique Method for Psoas Major Muscle: Case Study (대요근에 대한 근에너지기법을 이용한 자세이완기법 적용: 사례연구)

  • Choi, Sung-hwan;Hong, Hyun-pyo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.23 no.1
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    • pp.59-62
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    • 2017
  • Background: Positional release muscle energy technique (PRMET) is a method joined positional release technique and muscle energy technique. Methods: Subjects those who have low back pain from the acute to chronic phase, were applied PRMET method on psoas major muscle and measured the changes in pain and disfunction. Results: PRMET method is effective for reducing pain and disfunction on psoas major muscle. Conclusions: The advantages of PRMET method are minimized patient inconvenience, shortening of treatment time and effective for improvement. In the future research, methods need to be improved so that this can be applied to other muscles.

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A CASE REPORT OF RECONSTRUCTION OF FACIAL PARALYZED PATIENT (안면신경마비 환자의 재건에 관한 증례보고)

  • Choi, Moon-Gi
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.27 no.3
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    • pp.288-297
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    • 2005
  • Rehabilitation of the paralyzed face as a result of trauma or surgery remains a daunting task. Complete restoration of emotionally driven symmetric facial motion is still unobtainable, but current techniques have enhanced our ability to improve this emotionally traumatic deficit. Problems of mass movement and synkinesis still plague even the best reconstructions. The reconstructive techniques used still represent a compromise between obtainable symmetry and motion at the expense of donor site deficits, but current techniques continue to refine and limit this morbidity. In chronically paralyzed face, direct nerve anastomosis, nerve graft, or microvascular-muscle graft is not always possible. In this case, regional muscle transposition is tried to reanimate the eyelid and lower face. Regional muscle includes maseeter muscle, temporalis muscle and anterior belly of the digastric muscle. Temporalis muscle is preferred because it is long, flat, pliable and wide-motion of excursion. In order to reanimate the upper and lower eyelid, Upper eyelid Gold weight implantion and lower eyelid shortening and tightening is mainly used recently, because this method is very simple, easy and reliable.

The Effect of Stretch-Shortening Cycle on the Joint Power of the Jireugi in the Taekwondo Juchumseogi Stance (태권도 주춤서 지르기에서 Stretch-Shortening Cycle 이 관절파워에 미치는 효과)

  • Choi, Chi-Sun;Chung, Chul-Soo;Shin, In-Sik
    • Korean Journal of Applied Biomechanics
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    • v.24 no.1
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    • pp.1-9
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    • 2014
  • The purpose of this study was to investigate the muscle mechanical properties of the pelvic axial pre-rotational movement for the Jireugi in the Taekwondo Juchumseogi stance. Eleven elite Taekwondo Poomsae athletes participated. Each participant performed 5 right hand Jireugi in Juchumseogi stance as fast and strong as possible while their motion was recorded by a 3D motion analysis system and the ground reaction forces by two force plates. The power and work of the muscular group surrounding the waist were analyzed to verify the effect of the stretch-shortening cycle (SSC) theory. The cause of the greater power seems to be the application of the SSC by the muscles surrounding the waist during the preparation phase of the pre-rotation group. For the none pre-rotation group, they only used the concentric contraction of the muscles surrounding the waist. Because the pre-rotation group used the SSC theory, they had the effect of shortening of the range of movement, creating a fast and more powerful rotation, thus anticipating the increase the magnitude of impact.

식육의 연화증진에 관한 최근의 연구동향 - 적색육의 연도 증진에 이용되는 전기자극의 작용 -

  • 황인호
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2002.05a
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    • pp.17-25
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    • 2002
  • Application of electrical stimulation in the red meat species (eg. beef and sheep) processing has been erratic around the world and this may reflect an incomplete knowledge of how to optimise the technology. Although it is well established that stimulation increases the rate of post-mortem glycolysis other biochemical and biophysical effects have been implicated with the use of this technology. On the basis of currently available knowledge, this mini-review seeks to examine the current theories about the effect of stimulation on post-mortem muscle. The classical view that stimulation prevents muscle from shortening excessively during rigor development has been expanded to include the possibility that it also results in physical disruption of muscle structure. The interaction of these effects with the acceleration of the rate of proteolysis through activation of the calpain protease system has not been comprehensively reviewed in the past. As a result of conclusion driven, this article highlights several areas that may prove fruitful for further research. The challenge for further development of electrical stimulation systems is optimisation of the activation of the enzyme systems in parallel with manipulation of chilling regimes so as to ensure rigor mortis is achieved at temperatures which minimise shortening. The potential of regional stimulation of sections of the carcass to achieve this outcome is worthy of study given the different fibre composition of muscles and temperature gradients.

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Effects of Active and Passive Hamstring Stretching on Pelvic Mobility in Low Back Pain Patients (뒤넙다리근 능동과 수동신장 운동이 요통 환자의 골반 가동성에 미치는 영향)

  • Jung, Seung-Hwa;Park, Dae-Sung
    • Journal of the Korean Society of Physical Medicine
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    • v.16 no.1
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    • pp.49-61
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    • 2021
  • PURPOSE: Hamstring muscle shortening is related to low back pain, and it is important to check the hamstring muscle flexibility and pelvic mobility to analyze the effects of the intervention. This study examined the effects of hamstring muscle shortening on flexibility and pelvic mobility according to the method of stretching the hamstring muscle in patients with low back pain. METHODS: Forty Low Back Pain Patients participated. The subjects performed the Visual Analogue Scale (VAS), Fear Avoidance Belief Questionnaire (FABQ), Korean version of Oswestry Disability Index (KODI), Myovision, and sensbalance therapy cushion (pelvic mobility, proprioception). The subjects were divided into two groups to perform the passive and active stretching protocol. The intervention was conducted three times a week for four weeks. RESULTS: Hamstring muscle flexibility was increased significantly in both groups (p < .05), and there was no difference between the groups. VAS, FABQ was decreased significantly in both groups (p < .01), and there was no difference between the groups. The left lower back muscle impedance was decreased significantly in both groups (p < .05). The passive stretching group showed a significant increase in the pelvic anterior, posterior, and left tilt ROM (p < .05). The active stretching group showed a significant increase in the pelvic anterior, posterior tilt ROM (p < .05). CONCLUSION: Both stretching methods may be useful intervention methods for pelvic mobility and pain recovery and can assess back pain recovery.

Effects of Mobilization With Movement Using Posterior Talus Glide Taping Added Myofascial Release on Kinematic Data of Dynamic Balance in Individuals With Calf Shortening (종아리근 단축 대상자에게 목말뼈 후방활주 테이핑을 이용한 관절가동술 적용과 근막이완기법의 적용이 동적 균형의 운동학적 변화에 미치는 영향)

  • Seo, Min-A;Jeong, Kyu-Na;Kim, Yu-Jin;Lee, Yu-Jin;Hwang, Young-In
    • Physical Therapy Korea
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    • v.29 no.1
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    • pp.70-78
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    • 2022
  • Background: Individuals with calf muscle shortening may have decreased dynamic balance. Objects: This study aimed to investigate the effect of mobilization with movement (MWM) and myofascial release (MFR) on kinematic changes in dynamic balance in individuals with calf muscle shortening. Methods: Thirteen participants were randomly assigned to the MWM or the mobilization with movement added myofascial release (MWM-MFR) group. The MWM group received treatment with only MWM, whereas the MWM-MFR group was treated with MWM and MFR. Pre- and post-intervention passive range of motion (PROM), maximum reaching lengths, and modified star excursion balance test (MSEBT) results were compared for all participants. Wilcoxon signed-rank test and Mann-Whitney U test were used for statistical analysis. Results: The results showed significant within-group differences in ankle PROM, but no significant between-group differences. The maximum reaching length in the MWM-MFR group in the posterolateral direction was significantly different before and after the intervention (p = 0.005). This group also showed significantly reduced ankle abduction in MSEBT during the posteromedial direction section 3 (p = 0.007) and posterolateral direction section 5 (p = 0.049) compared with the MWM group. Conclusion: Combined MWM and MFR intervention improves ankle stability in the coronal plane during the posteromedial and posterolateral forward movement in dynamic balance compared with only MWM in individuals with calf shortening.

The Role of the Cricopharyngeus Muscle in Pitch Control - Electromyographic and radiographic studies

  • Hong, Ki-Hwan;Kim, Hyun-Ki;Yang, Yoon-Soo
    • Speech Sciences
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    • v.11 no.1
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    • pp.73-83
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    • 2004
  • Electromyographic studies of the cricopharyngeus muscle using hooked wire electrodes were performed in thyroidectomized patients. The shape of the cricoid cartilage and soft tissue thickness in the postcricoid area were evaluated during pitch elevation and pitch lowering using conventional neck lateral films. The cricopharyngeus muscle simultaneously activated in the initial task of speech and continuously activated. Its activity lessened in the interrogative stress contrast of sentence terminals and increased in the pitch lowered contrast of sentence terminal. On the radiologic findings the cricoid cartilage was tilted backward during high pitched phonation and tilted forward during low pitched phonation. The soft tissue thickness of postcricoid area was thicker at the low pitch than at high pitch. At low pitch the cricoid cartilage paralleled along the vertebral column. This result suggests that the bulging of cricopharyngeus muscle in contraction induce a thickened the postcricoid area thickened, and exert pressure anteriorly exerted on the cricoid cartilage. This contraction of the cricopharyngeus muscle may result in shortening the vocal fold and lowering pitch.

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