• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.421-429
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• 2007

Some researchers suggested that tactile sensor system would be useful in evaluating masticatory muscles of TMD patients, but there were few studies on the effects of chewing with time. The aim of this study was to investigate the change of elasticity and stiffness for masseter and temporal muscles of normal subjects before, during and after gum chewing and to obtain the baseline data for further researches on the elasticity and stiffness for masticatory muscles of TMD patients. Stiffness and elasticity of their anterior temporalis and inferior masseter muscle were measured bilaterally by a tactile sensor system. Each subject was instructed to sit on a chair for evaluation of masticatory muscles. Before operating the sensor, the thickest skin area over anterior temporalis and inferior masseter muscles were selected as the points to be pressed by a tactile sensor, and marked with a pen. While the teeth of subjects were lightly contacted, the probe of the tactile sensor was placed perpendicularly over the marked point over the skin, followed by computer-controlled movement including gently pressing straight down on the muscle for a second and retracting. All subjects were instructed to chew gum (Excellent Breath, Taiyo Co., Japan) bilaterally with a velocity of 2 times per second for 40 minutes after the first measurement had been performed for the baseline data of all subjects. The measurements had been repeated during chewing with 10 minutes of interval and continued for 40 minutes with same interval after chewing. Resultantly, the decrease of elasticity and the increase of stiffness in masticatory muscles can be seen significantly within 10 minutes after chewing and those were maintained during chewing without significant change with chewing time. The elasticity of muscles was recovered within 10 minutes after stopping chewing, but the stiffness was recovered more lately than elasticity by about 10 minutes. Based on these results, it can be concluded that elasticity and stiffness of muscles would be good indicators to evaluate the masticatory muscles objectively, when more supported by further researches.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.229-230
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• 2008

• The korean journal of orthodontics
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• v.22 no.2 s.37
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• pp.389-412
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• 1992

Along with form and function relationship of craniofacial growth comes a concern for the masticatory muscles with postnormal occlusion. It is the aim of this study to grope the certain differences upon the electromyographic activities of the masticatory muscles between normal occlusion and class II malocclusion during the varieties of oral functions. 26 persons of normal occlusion whose mean age were 18.9-25.6 years and another 26 persons of class II malocclusion whose mean age were 19.0-28.9 years served for this study. The electromyographic recordings processed by $Medelec^{\circledR}$ MS 25 EMG apparatus were taken from the anterior and posterior temporal, and anterior and posterior masseter muscles of both sides, and suprahyoid muscles as well. Analyses of the data toward such specific activities as mandibular rest, maximal biting, chewing gums and swallowing peanuts turned out the following summary and conclusions. 1. The maximal mean amplitude of the posterior temporalis showed significant augmentation in class II malocclusion, however the anterior temporalis, posterior masseter, and suprahyoid muscles manifested meaningful diminutions. 2. Stronger posterior temporalis and weaker anterior masseter and suprahyoid muscles were arranged in maximal biting with parameters of maximal mean amplitude. 3. The anterior temporalis of working side expressed smaller maximal mean amplitude in class II malocclusion. Significant swelling in duration were shown at anterior and posterior temporalis of working side, and posterior temporalis of balancing side in class II malocclusion, and marked reduction at anterior masseter of balancing side and posterior masseter of working side as well. The lessened latency were expressed at anterior masseter of working side, and anterior and posterior masseter of balancing side. Class II malocclusion group had significant prolongation of silent period duration. Mean silent period duration of 10.75 msec in normal occlusion and 24.37 msec in class II malocclusion were calculated. 4. Significant augmentations of maximal mean amplitude while swallowing peanuts were yielded at right anterior temporalis and posterior temporalis of both sides, however left anterior masseter and right posterior masseter showed diminution. No significant differences in duration showed at every muscle examined in class II malocclusion group.5. Weaker masseter and stronger temporalis were suggested as characteristics of class II malocclusion.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.138-143
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• 2008

A study was conducted to evaluate nutritional value for twenty-one pork muscles. Ten market-weight crossbred pigs (five gilts and five barrows) were used for evaluating proximate chemical composition, cholesterol, total iron, calorie and fatty acid contents. As preliminary analysis revealed no noticeable sex effect, pooled data from both sexes were used for the final analysis. M. rectus femoris had the highest moisture content, while m. latissimus dorsi was lowest in moisture content (p<0.05). Protein content was highest for m. longissimus dorsi and lowest for m. supraspinatus (p<0.05). The tensor fasciae and latissimus dorsi muscles contained the highest intramuscular fat (p<0.05), while rectus femoris, adductor and vastus lateralis were lowest in intramuscular fat content. When simple correlations between chemical values were computed for the pooled dataset from all muscles, intramuscular fat had significant (p<0.05) negative linear relationships with moisture (r = -0.85) and protein (r = -0.51) contents. Calorie levels were not significantly affected by fat content, while rectus femoris and latissimus dorsi muscles showed lowest and highest calorie contents, respectively (p<0.05). Polyunsaturated fatty acid content was highest (p<0.05) for both m. adductor and m. rectus femoris, while it was lowest for m. longissimus dorsi. Collectively, the current study identified a large amount of variation in nutritional characteristics between pork muscles, and the data can be used for the development of muscle-specific strategies to improve eating quality of meats and meat products.

• Physical Therapy Korea
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• v.16 no.3
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• pp.9-15
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• 2009

The purpose of this study was to examine contraction of abdominal muscles on surface electromyographic (EMG) activity of superficial cervical flexors, rib cage elevation and angle of craniocervical flexion during deep cervical flexion exercise in supine position. Fifteen healthy subjects were participated for this study. All subjects performed deer cervical flexion exercise with two methods. The positions of two methods were no volitional contraction of abdominal muscles in hook-lying position with 45 degree hip flexion (method 1) and 90 degrees hip and knee flexion with feet off floor for inducing abdominal muscle contraction (method 2). Surface EMG activities were recorded from five muscles (sternocleidmastoid, anterior scaleneus, recuts abdominis, external oblique, internal oblique). And distance of rib cage elevation and angle of craniocervical flexion were measured using a three dimensional motion analysis system. The EMG activity of each muscle was normalized to the value of reference voluntary contraction (%RVC). The EMG activities, distance of rib cage elevation. and angle of craniocervical were compared using a paired t-test between two methods. The results showed that the EMG activities of sternocleidmastoid and anterior scaleneus during deep cervical flexion exercise in method 2 were significantly decreased compared to method 1 (p<.05). Distance of rib cage elevation and angle of craniocervical flexion were significantly decreased in method 2 (p<.05). The findings of this study indicated that deep cervical flexion exercise with contraction of abdominal muscles could be an effective method to prevent substitute motion for rib cage elevation and contraction of superficial neck flexor muscles.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.669-673
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• 2011

Purpose: The authors have conducted a series of anatomic studies on the factors affecting shape of a lower vault in Asian noses. The results of the studies showed that prominence of alar lobule is mainly affected by the volumes of the dilator naris anterior and posterior muscles and the insertions of the dilator naris posterior muscles. However, information on its clinical availability is yet insufficient. The present study was undertaken for clinical purpose to find out the effect of dilator naris muscle resection on the correction of prominent alar lobule. Methods: Six patients who were treated by dilator naris muscle resection with a long-term follow-up of more than 1 year were involved in this study. Rhinoplasties were performed via endonasal approaches with resecting dilator naris anterior and posterior muscles by sharp scissor. The effect of the dilator naris muscle resection on alar prominence was investigated by measuring ratio of the short axis to the long axis of a nostril (SA/LA) pre-and postoperatively. The visual analog scale (VAS) was also used to evaluate satisfaction of patients. An average follow-up time was $15.6{\pm}3.7$ months. Results: Having lost the dilating and lateral pulling effects of the dilator naris muscles, the alar lobule shifted medially and alar lobule shapes improved. SA/LA significantly improved (preoperatively $0.71{\pm}0.11$ and postoperatively $0.58{\pm}0.08$; $p$ <0.05). The VAS score was also increased postoperatively (preoperatively $3.2{\pm}1.8$ and postoperatively $8.7{\pm}1.2$; $p$ <0.05). A mild degree of hyperpigmented scar was noted in one alar lobule. Otherwise, there was no case of postoperative complication. Conclusion: Our results suggest that prominent alar lobule could be modified by resecting the attachment of the dilator naris muscles. This maneuver removes the function of dilator naris muscles, then may produce a more aesthetically acceptable alar lobule shape.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.475-482
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• 2020

The abdominal drawing-in maneuver(ADIM), which is performed to strengthen the stabilization muscles of the lumbar, is an exercise method that selectively contracts the TrA and IO by increasing intra-abdominal pressure. In order to check the effect of ADIM in sitting position, which is the most frequently used posture in everyday life, on how to grip power, ADIM was conducted in a sitting position for 30 healthy adults, and then the state was not performed. In each, the grip power was measured to determine how ADIM performed in the sitting position had an effect on grip power and which muscles had the most influence. The muscles mobilized for the electromyography(EMG) measurement were RA, EO, IO/TrA, and ES, which were the most activation lumbar stabilization muscles when ADIM was applied. As a result of the study, the activity on muscles of the lumbar stabilization was significantly increased and the grip power of the muscles was significantly increased than the ADIM in the sitting position. By comparing the measured difference value of each muscle, it was found that any muscle had a greater effect on grip power, but no muscle showed a significant correlation. It is thought that the increase of intra-abdominal pressure did not affect the grip power of a specific muscle. Therefore, if ADIM is performed in a sitting position that is frequently used in everyday life through this study, it will be more effective in increasing the grip power and lumbar stabilization.

• Animal Bioscience
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• v.34 no.9
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• pp.1514-1524
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• 2021

Objective: This study investigated the meat quality characteristics, endogenous proteolytic enzymes, collagen content, and myosin heavy chain (MyHC) isoforms of different muscles of Thai native cattle (TNC). Methods: Infraspinatus (IF), Longissimus thoracis (LT), and Supraspinatus (SS) muscles were obtained from two TNC breeds, Kho-Lan (KL, n = 7) and Kho-Isaan (KI, n = 7). The muscle and meat characteristics of TNC breeds and their relationship with MyHC expression were examined. Results: Three MyHC isoforms namely MyHC I, MyHC IIa, and MyHC IIx were detected in the muscles. The KL had higher (p<0.05) MyHC IIx than the KI. The IF muscle had higher (p<0.05) MyHC I compared to other muscles. The LT muscle had the least MyHC I. The LT had higher (p<0.05) MyHC IIx than the IF and SS muscles. The IF presented the least MyHC IIx. The KL had higher (p<0.05) lightness and moisture content and lower crude protein, redness, cooking loss, shear force, and calpastatin than the KI. The glycogen, total collagen, soluble collagen, crude protein, ash contents, and troponin T degradation product of IF and SS were lower (p<0.05) than that of LT. Ether extract in LT was lower (p<0.05) than that of IF and SS. The percentage of MyHC I, MyHC IIa, and MyHC IIx were significantly correlated with muscle and meat characteristics of TNC. Conclusion: These results suggest that the differences in the MyHC isoforms may partly account for the variation in meat quality between breeds and among muscles of TNC.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1303-1308
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• 2004

The beef color stability during display of two muscles, m. longissimus thoracis and m. semitendinosus, of Japanese Shorthorn steers (n=14) was compared with that of Japanese Black steers (n=14). The beef color of each carcass was evaluated according to the Japanese Grading Standards at 24 h post mortem. Steak samples from muscles were over-wrapped with PVC film and displayed under fluorescent lights at $4^{\circ}C$ for 9 days. Metmyoglobin percentages of steak samples were determined at days 0, 3, 6 and 9. The overall grade of beef color of the carcasses of Japanese Shorthorn steers was significantly (p<0.05) lower than that of Japanese Black steers. The metmyoglobin percentages during the display of two muscles of Japanese Shorthorn steers were significantly (p<0.05) lower than those of Japanese Black steers. These results suggested that though beef color evaluation of the carcasses of Japanese Shorthorn steers was lower than that of Japanese Black steers, the beef color stability during the display of the muscle of Japanese Shorthorn steers was higher than that of Japanese Black steers.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.197-204
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• 2006

The purpose of this study was to investigate the relationship between the cumulative fatigue of trunk muscles and the period of recovery time during repetitive lifting and lowering task with two different frequencies(4 times/min and 6 times/ min). Eight healthy males with no prior history of LBD(low back disorders) volunteered for this study. Subjects had 2, 3, 4, and 5 minutes recovery time respectively while they were preforming the lifting and lowering task at 15% level of MVC. EMG signals from six trunk muscles were collected and the fatigue level was analyzed quantitatively. In results, the fatigue levels of LES(left elector spinae), RLD(right lattissimus dorsi), LLD(left lattissimus dorsi), RRA(right rectus abdominis) and LRA(left rectus abdominis) were recovered when 3 minutes recovery time was given at 4 times/min frequency. However, the fatgue level of RES(right elector spinae) was recovered when 4 minutes recovery was given. On the other hand, when 6 times/min frequency was used, the RLD, LLD, RRA and LRA were recovered at 5 minutes of recovery time. But for RES and LES, it took longer than 5 minutes to be recovered. This results can be applied to design the adequate length of recovery time to control the cumulative fatigue of trunk muscles in industry with repetitive lifting and lowering task.