The purpose of this study was to investigate the effect of the two different types of chairs on trapezius muscle activation during dictation tasks. Seventeen university students, each of whom were within standard deviation of the mean Korean standard body size, voluntarily participated in this study. Surface electromyography was used to collect electrical signals from both the upper and lower trapezius muscles. Amplitude Probability Distribution Function (APDF) was performed to analyze the muscle activity. The findings of this study were 1) The backrest-point height of the auditorium chair and the height, length and width of the connected desk were shorter than what was suggested by the KS. Another difference was that the auditorium chair had a bigger angle of the backrest compared to the classroom chair. 2) Regarding within-subject effect the sole statistically significant difference was found between activation of the upper trapezius muscle. The upper trapezius muscle's %RVC in the APDF 10th-50th-90th percentile was statistically higher for participants sitting in the auditorium chair than for participants sitting in the classroom chair (p<.05). 3) There was an interaction effect between the 'two chair-types' and the 'two muscle-sides' in the APDF 10th-50th percentile (p<.05). 4) There was an interaction effect between the 'two chair-types' and the 'three gaze-direction' in the APDF 90th percentile (p<.05). The findings of this study indicated that maintaining a writing posture for a prolonged period of time in an auditorium chair significantly increased the left upper trapezius muscle activation compared to a classroom chair.

The purpose of this study was to determine the effect of contralateral hip adduction (CHA) on thickness of lumbar stabilizers during hip abduction in side-lying. Twenty healthy subjects without back pain were recruited for this study. The thickness of transverse abdominis (TrA), internal oblique (IO) and quadratus lumborum (QL) were measured by ultrasonography. Pelvic lateral tilting motion was measured using a three-dimensional motion analysis system. Measurements were performed at rest position (RP), preferred hip abduction (PHA) and abduction with contralateral hip adduction (CHA) in side-lying at the end of expiration. During the measurements, subjects were asked to maintain steady trunk alignment without hand support. Thickness of TrA and IO was significantly greater in CHA than in PHA and RP conditions. There was no significant difference in thickness of TrA and IO between PHA and RP conditions. Medio-lateral (M-L) thickness of QL was not significant between PHA and CHA conditions. Anterio-posterior (A-P) thickness of QL in PHA and CHA significantly decreased compared to RP condition. Angle of pelvic lateral tilting was significantly decreased in CHA compared to PHA condition. In conclusion, CHA can be recommended for increasing trunk stability without compensatory pelvic motion during hip abduction exercise in side-lying.

Myositis ossificans traumatica(MOT) in head and neck area is a rare non-neoplastic, heterotopic bone formation within a muscle, arising after trauma or surgery. Although the several case reports have described the occurrence of MOT in other muscles of oro-facial musculature, MOT has never been reported in mentalis muscle. We demonstrate a case of MOT occurred in mentalis muscle of a 64 years old male. He recently complained of a movable mass with no pain. He had experienced a hitting trauma on his right anterior mandible about 25 years ago. Since then, the trauma area has been asymptomatic. The lesion showed severe muscular degeneration, resulted in a pseudocystic change without epithelial lining. The ectopic ossification was closely associated with the fibrous fascia of adjacent muscles. The lesion contained a lot of basophilic materials admixed with atrophying cells, which were supposed to be derived from muscle parenchyma injured previously. It was presumed that the basophilic materials induced callus-like ossification in the fibro-muscular lesion, also recruited macrophages and fibroblasts. However, the ossification processes in MOT were predominantly characterized by dystrophic calcification without osteoblastic differentiation of mesenchymal cells. Even more, there appeared some skeletal muscle bundles which were calcified dystrophically. Therefore, we suggest the present case of MOT might be initiated by dystrophic calcification in the degenerating muscle tissue

A rapid, simple and reliable LC-MS/MS method, which can be used on a routine basis, was developed for the simultaneous detection of 8 penicillin antibiotics (amoxicillin, ampicillin, penicillin-G, penicillin-V, oxacillin, cloxacillin, nafcillin and dicloxacillin) in swine muscle and kidney. The antibiotics were extracted from samples with water and methanol. The extract was centrifuged, filtered and analyzed by liquid chromatography coupled with a tandem mass spectrometer (LC-MS/MS), using a C18 reversed phase column with water/acetonitrile gradient containing 0.05 % formic acid. Mass spectral acquisition was achieved in an electrospray positive ion mode by applying multiple reaction monitoring (MRM) of 2 fragment ion transitions to provide a high degree of sensitivity and specificity. The ion rations were consistent and could be used for confirmation of identity of the penicillin antibiotics. Recoveries of eight penicillins at three fortification levels (10, 20 and 40㎍/㎏) ranged from 79.8 to 102.4% and 72.8 to 103.4% in swine muscle and kidney, respectively. The coefficient of variation was than 9% in all samples. The estimated limits of quantification (LOQs) ranged from 1.0 to 3.2㎍/㎏ in swine muscle and kidney, respectively. The LOQs of this method are below the MRLs of penicillin antibiotics in animal tissues established in Korea and other countries.

This study was carried out to investigate the effect of muscle part and aging period on free amino acids and aroma compounds of Hanwoo (Korean cattle) cow beef. The M. longissimus (ML) and M. semitendinosus (MS) from 101 mon-old-cows were aged at 2℃ for 14 d. The free amino acids concentration increased in both ML and MS on 14 d of aging. In ML, asparagine, glutamine, histidine, glycine, threonine, arginine, tyrosine, phenylalanine, isoleucine, leucine and lysine were significantly (p<0.05) higher than those in MS. Varieties of aldehydes, ketones, alcohols, hydrocarbons, nitrogen and sulfur compounds were detected in both ML and MS and majority of these compounds showed increasing trend on aging. The ML had higher 14 aldehydes (acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2- methylbutanal, pentanal, hexanal, heptanal, E-2-heptanal, octanal, 2-octenal, 2-nonenal, E-2-decenal, E,E-2,4-decadienal and 2-undecenal), 5 ketones (2-propanone, 2,3-butanedione, 2-butanone, 2-heptanone and 2,3-octanedione), 4 alcohols (ethanol, 1-pentanol, 1-hexanol and 1-octanol), 3 hydrocarbons (3-ethyl-2-methyl-1,3-hexadiene, 3- methyldecane and 2,2-dimethyloctane) significantly (p<0.05) compared with MS. However, the MS had higher 5 nitrogen and sulfur compounds (methanethiol, dimethyldisulfide, fufural, 2,5-dimethylpyrazine and 2-octylfuran) significantly (p<0.05) compared with ML.

The purpose of this study was to assess visual biofeedback's influence on trunk muscles' (EMG) activity and endurance holding time for correct position during whole-body tilt exercise. For the study, we recruited 14 volunteers who showed no symptom of lumbar disease during medical tests. We measured the EMG activity of their rectus abdominis, external abdominal oblique, internal abdominal oblique and erector spinae muscles, and their endurance holding time for correct position during anterior and posterior whole-body tilt under two conditions: whole-body tilt with and without visual biofeedback. Resistance with gravitational force on the trunk during whole-body tilt was applied by using a device that had a monitor on which the subjects could check their alignment and that sounded an alarm if a subject's alignment collapsed. The study showed an increase in the EMG activity of external abdominal oblique, internal abdominal oblique/rectus abdominis ratio and endurance holding time for correct position during both anterior and posterior whole-body tilt with visual biofeedback compared with without visual biofeedback (p<.05). We suggest that the whole-body tilt exercise with visual biofeedback could be a beneficial strategy for selectively strengthening the internal abdominal oblique muscle and minimizing the rectus abdominis muscle's activity while maintaining correct alignment during whole-body tilt exercise.

본 연구에서는 유머를 경험하는 동안 나타나는 아동의 안면근육반응을 확인하고 유머 정서에 의해 유발된 안면근육반응과 우울 수준과의 관계를 연구하였다. 실험에 앞서 또한 아동의 우울 수준을 측정하기 위하여 12~13세의 아동 43명(남 22명)에게 한국판 PIC 검사의 우울 척도를 평가하도록 하였다. 실험이 시작되면, 자극이 제시되기 전 60초 동안 안정 상태를 측정한 후, 유머를 유발하는 시청각 동영상 자극을 제시하는 동안 안면근육반응(양측 추미근, 구륜근)을 측정하였다. 자극 제시가 끝나면 자신이 경험한 정서를 정서평가척도 상에 평가하도록 하였다. 아동의 95.3%(41명)이 유머를 경험하였다고 보고하였고 그 강도는 3.81(5점 만점)로 나타났다. 안면근육반응은 안정 상태에 비하여 유머 자극이 제시되었을 때 유의하게 증가하였다. 안면근육반응과 우울 수준과의 상관을 확인한 결과, 우측 추미근에서 유의한 부적 상관이 나타났다. 이는 우울 점수가 높은 아동일수록 유머를 경험할 때 안면근육을 적게 움직임을 의미한다.

In this study, the effects of psychosocial stress (box color and precision demand) on muscle activity were evaluated in laboratory setting. Eight subjects performed sagittally symmetric lifting tasks. Box color (yellow, black), precision demand (yes, no), and box weight (5%MVC, 10%MVC, 15 %MVC) were varied and surface EMG signals from seven muscles(medial deltoid right, biceps brachii right, lateral triceps right, latissimus dorsi right, erector spinae right, external oblique right, internal oblique right) were recorded. EMG signals were band-pass filtered(10~400 Hz), rectified, RMS smoothed and normalized (NEMG). Analysis of variance tests were conducted on the total NEMG (TNEMG: the sum of the seven muscles' NEMGs) and on the individual muscle's NEMGs. Box color had no effect on the TNEMG and on the seven muscles activities(p〉0.05). When precision demand was required at the end point of lifts, the mean NEMG showed higher values than no precision demand conditions: TNEMG (14% increase) and medial deltoid(40% increase), biceps brachii(10% increase), lateral triceps(26% increase), latissimus dorsi(25% increase) muscles. Those increases showed more conspicuous as the box weight increased in the muscles of medial deltoid, lateral triceps, and latissimus dorsi.

The purpose of this study was to investigate the effects of a repetitive lifting task on the level of activation and median frequency of the paraspinal muscles, and to provide basic data of the maximal acceptable duration of the lifting task to avoid muscle fatigue. Ten healthy male subjects were recruited as participants and they repetitively (12 lifts/min) lifted a box (46 ㎝ × 30 ㎝ × 30 ㎝, 15 kg) for 10 minutes. Electromyographic data (muscle activation and median frequency), heart rate, and Borg CR10 score were recorded at 1, 3, 5, 7, and 9 minutes after the lifting task. Electromyographic data was recorded from the elector spinalis, mutifidus, external oblique abdominis, and rectus abdominis for 1 minute. The results showed that as the repetitive lifting task progressed, the heart rate and Borg CR10 score significantly increased. In addition, activation of the muscles increased. The median frequency significantly decreased over time in the elector spinalis, mutifidus, and external oblique abdominis (right side), except for the external oblique abdominis (left side) and rectus abdominis. It is suggested that the median frequency recorded from a dynamic task is used to monitor muscle fatigue. Furthermore, the repetitive lifting task (15 kg, 12 lifts/min) should not continue for more than 3 minutes in order to avoid muscle fatigue.

본 연구는 뇌졸중 후 발생한 삼킴 장애 환자를 대상으로 목근육에 표면 전극을 이용한 전기 자극 치료가 삼킴 장애에 미치는 영향을 알아보고자 하였다. 연구방법 : 본 연구는 연세대학교 원주의과대학 부속 원주기독병원에서 뇌졸중으로 진단 받은 사람으로서 삼킴 장애가 비디오투시검사를 통해 확인된 18명을 대상으로 하였다. 자연회복 여부를 확인하기 위하여 2주 동안 삼 킴 장애 치료를 목적으로 한 어떠한 처치도 받지 않았고, 그 후 전기 자극 치료를 하루 1시간, 일주일에 5회, 4주간 실시하였다. 삼킴 기능의 변화를 알아보기 위하여 2주 통제 기간 전후와 전기 자극 치료 2주후, 전기 자 극 치료 4주 후에 비디오투시검사를 실시하여 각 대상자별 4회의 검사가 실시되었다. 녹화된 동영상을 바탕으 로 연하 곤란 척도와 인두 통과 시간을 측정하였다. 결과 : 대상자들은 통제기간동안 삼킴 기능의 변화가 없었지만(p>.05), 2주간의 전기 자극 치료 후 유의한 삼킴 기능의 향상을 보였으며(p<.05), 4주 전기 자극 치료 후에도 2주 전기 자극 치료 후보다 유의한 삼킴 기능의 향 상이 있었다(p<.05). 그러나 인두통과시간은 2주 치료 후, 4주 치료 후 모두 유의하게 변하지 않았다(p>.05). 삼 킴 후 인두기의 잔여물은 양배꼴동, 후두개곡에서 유의하게 줄어들었다(p<.05). 결론 : 본 연구 결과 대상자들은 2주 기간 동안 삼킴 기능의 자연 회복을 보이지 않았고 전기 자극 치료 후에 유의 한 기능 향상을 보여 전기 자극 치료의 효과를 증명하였다. 대상자들은 2주 전기 자극치료에서 뿐만 아니라 4주 치료 후에도 계속적인 기능 상승을 보였는데 앞으로는 본 연구보다 장기적인 치료의 효과와 이의 지속여부를 확 인하는 연구가 필요할 것으로 생각된다. 또한 인두통과시간은 삼킴 기능의 변화를 민감하게 나타내지 못하였으 므로 인두 통과 시간만을 측정하는 삼킴 기능의 평가는 추후 연구에서도 주의가 필요할 것으로 생각된다.

This study investigated the irradiation pattern of muscles on the affected side in stroke patients after application of diagonal 2 extension (D2 ex) proprioceptive neuromuscular facilitation in the unaffected upper extremity. Seven stroke patients participated. Electromyographic activities were recorded in the iliopsoas, biceps brachii, and triceps brachii were recorded by surface electrodes at rest, D2 ex with knee extension, and D2 ex with knee 90 flexion, normalized by maximal voluntary isometric contraction (MVIC) values. The medial frequencies of biceps brachii in both sides were also measured to compare muscle type recruited. %MVIC of biceps brachii and triceps brachii were significantly higher in D2 ex than at rest (p<.05). There was no difference in median frequency of biceps brachii between the affected and unaffected side (p>.05). This suggests that proprioceptive neuromuscular facilitation using D2 ex may improve muscle activities of the paretic side and that the irritation pattern of the affected side may respond to maintain body equilibrium according to movement of the sound side.

Anticipatory postural adjustments is an example of the ability of the central nervous system to predict the consequence of the mechanical effect of movement on posture and helps minimize a forth coming disturbance. The aim of this study was to evaluate the sequence of activation of the trunk muscles during the performance of hip and shoulder movement and to determine the relationship between anticipatory activity and subjects' motor and functional status in subjects with hemiplegia post stroke. Twenty-four poststroke hemiparetic patients enrolled in this study. Electromyographic activity of the lumbar erector spinae, latissimus dorsi, and of the obliquus internus muscles was recorded bilaterally during flexion of both arm and from the rectus abdominis, obliquus externus, and obliquus internus muscles during flexion of both hip. Onset latencies of trunk muscles were partially delayed in the subjects with hemiplegia post stroke (p<.05). With upper limb flexion, the onset of erector spinae muscle and latissimus dorsi muscle activity preceded the onset of deltoid on both side respectively (p<.05). A similar sequence of activation occurred with lower limb flexion. Also the onset of external oblique muscle and rectus abdominis muscle activity preceded the onset of rectus femoris muscle on both side (p<.05). Major impairments in the activity of trunk muscles in hemiparetic subjects were manifested in delayed onset between activation of pertinent muscular pairs. These problems were associated with motor and functional deficits and warrant specific consideration during physical rehabilitation of post stroke hemiparetic patients.

The effects of the applied stretch and MgADP binding on the structure of the actin and myosin cross-bridges in rabbit fibers in the rigor state have been investigatedwith improved resolution by x-ray diffraction using synchrotron radiation. To clarify the structure of the ATP hydrolysis intermediates formed by actin and myosin cross-bridges,the effects of various phosphate analogs in the of MgADP on the structure of the thin and thick filaments in glycerinated rabbit muscle fibers in the rigor state investigated by x-ray diffraction with a short exposure time using synchrotron radiation. These results strongly suggest that when MgADP and phosphate analogs such as metallofluorides(BeF3 and AlF4)and vanadate(VO4(Vi)) were added the rigor fibers in the presence of the ATP-depletion backup system, the intensities of the actin-based layer lines were markedly weakened. We found that the intensity of the 14.5 nm-based meridional reflections increase by 20-50% when phosphate analogs such as metallofluorides(BeF3 and AlF4) and vanadate(VO4(Vi)) was added to the rigor muscle.

Choline is important an organic compound for normal membrane function, acetylcholine synthesis, lipid transport, and methyl metabolism. In biological tissues and foods, there are multiple choline compounds that contribute to choline content. There are so many analytical methods for choline determination, such as radioisotopic, high-performance liquid chromatography, and gas chromatography/mass spectrometry. However, these existing methods are expensive, unmanageable, and time-consuming. In this study, we modified enzymatic method, which is applicable for the determination of choline in milk and infant formulas, and applied to bovine serum and muscle. The calibration curves were linear with higher correlation coefficients than 0.994 . Recoveries obtained by calibration curves from the spiked bovine serum and muscle samples varied between 70.6 and 85.2%. The method may be suitable for use as a routine method in the determination of choline for biological tissue and food samples.

With the introduction of the video display terminal (VDT), the efficiency and productivity of work has improved. However, VDT syndrome is threatening the health of workers as a side effect of prolonged use of a VDT. Among various VDT syndromes, the musculoskeletal disorder, especially, the cumulative trauma disorder (CTD) is the common research topic related with upper extremities function. The aim of this study was to investigate the effect of the wrist-hand orthosis (WHO) on fatigue in middle deltoid, anterior deltoid, serratus anterior, and upper trapezius during one-hour computer keyboard typing. Twelve healthy subjects participated in this study. Surface electromyography was used to assess the localized muscle fatigue (LMF), and the LMF was calculated at 10 minutes, 20 minutes, 40 minutes, and 60 minutes in each muscle, with and without the WHO. Data were analyzed by paired t-test with a level of significance of .05. The results of this study are as follows: 1) At 10 minutes, the LMF decreased significantly with applied WHO in the middle deltoid, anterior deltoid, and upper trapezius (p=.001, p=.026, p=.019, respectively). 2) As the computer keyboard typing period increased, there were no significant LMF differences, except for the upper trapezius. Therefore, it can be concluded that the WHO can be applied to decrease the LMF for the initial 10 minute period in the middle deltoid, anterior deltoid, and upper trapezius' but that the long term effect of WHO in reducing the LMF was proven only in upper trapezius during continued computer keyboard typing.

This study investigated gait characteristics, kinematics, and kinetics in the lower extremities between two different shoe conditions (high heeled shoes (7 cm), and high heeled shoes with a total contact insert (TCI)) after lower extremity muscle fatigue. Although TCI shave been applied in high heeled shoes to increase comfort and to decrease foot pressure, no study has attempted to identify the effects of TCI in fatigue conditions. The purpose of this study was to determine the effects of walking in high heeled shoes with TCI after lower extremity muscle fatigue was induced. This study was carried out in a motion analysis laboratory at Hanseo University. A volunteer sample of 14 healthy female subjects participated. All in fatigue conditions, the subjects were divided into two groups. The muscle fatigue was induced by 40 voluntary dorsi- and plantar-flexion exercises and 40 heel-rise exercises of the dominant foot. Surface electromyography was used to confirm the localized muscle fatigue using power spectral analysis of three muscles (tibialis anterior, gastrocnemius medialis and lateralis). The results were as follows: (1) In muscle fatigue conditions, the use of TCI decreased the peak flexion angle of the hip joint significantly in the early stance phase (p<.05) and increased the peak hip flexion moment in the terminal stance phase (p<.05). (2) In muscle fatigue conditions, the application of TCI also increased peak hip power generation in the early stance phase and peak hip power absorption in the terminal stance phase (p<.05). (3) In muscle fatigue conditions, the use of TCI reduced the impact force significantly and increased the secondary peak vertical GRF. These findings suggest that the TCI may provide beneficial effects when muscle fatigue occurs for a high heeled shoe gait. Future research employing the patient population and various types of TCI materials are required to clarify the effects of TCI.

To study the relationship between elementary biochemical states and structural states of the actomyosin crossbridges in muscle, the effects of binding of MgADP to myosin heads in the rigor muscle were examined by X-ray diffraction using synchrotron radiation. X-ray diffraction studies have been made to investigate the effects of binding of ADP on the structure of glycerinated rabbit skeletal muscle in the rigor state. The intensity increase was accompanied by a slight but distinct decrease in the 5.9 am layer-line intensity close to the meridian. These results strongly suggest that myosin heads altered their attached conformation in the proximal end toward the plane perpendicular to the fiber axis when MgADP was bound to them. We found that the intensity of the 14.5 nm-based meridional reflections increase by 20-50% when MgADP was added to the rigor muscle in the presence of hexokinase and myokinase inhibitor.

The purpose of this study was to verify the effects on fine motor, muscle strength (hand-grip), explosive muscular strength (vertical jump) and muscular endurance (sit-up) after ingesting coffee. Hence this study targeted a sample group of 38 healthy men in their twenties, without cardiac disorders and muscle disorders and none of them were hypersensitive to caffeine with symptoms such as palpitation and dyspnea. Nineteen of them ingested coffee, whereas the other nineteen men ingested decaffeinated coffee at the same amount. The amount of coffee was controlled by weight so as to regulate intake to 6 mg caffeine per kg. Research material was evaluated through O'Conner's finger dexterity test, hand-grip strength test, vertical jump test and sit-up test. The data were analyzed by means of paired t-test and ANCOVA. The material was then, analyzed by means of two-way ANOVA in order to verify the effect of one or two cups of coffee on fine motor and hand-grip strength. All parameters were measured by an independent observer. The results were as follows: There were no significant differences to fine motor, hand-grip strength, vertical jump, sit-up before and after drinking decaffeinated coffee, but there was a difference to those before and after drinking caffeine coffee. There was no significant difference to hand dexterity and hand-grip strength in one or two cups of coffee. Intake of a certain dosage of caffeine effects activation of muscles working in a short period based on the results. As a consequence, intake of certain dosages of caffeine was beneficial to enhance efficiency of activity during exercises, but it is will be difficult to obtain the desired result with only one or two cups of coffee.

X-ray diffraction studies have been made to investigate the effects of binding of ADP, ADP+Vi, ADP+AIF4, ADP+BeF3 on the structure of glycerinated rabbit skeletal muscle in the rigor state. Although these phosphate analogs are known to bind actively cycling myosin heads, it is not clear whether they can bind to the attached heads in the rigor muscle. We have found that these analogs can bind to the myosin heads attached to actin filaments in the rigor state. The present results indicate that (1) bound myosin heads altered their conformation in the proximal end toward the plane perpendicular to the fiber axis when MgADP bound to them, and (2) myosin heads were dissociated substantially (up to 50%) from actin filaments but still remained in the vicinity of actin filaments when MgADP and metallofluorides (AIF4 and BeF3) or vanadate bound to them. We detected new conformations of myosin heads attached to actin filaments when they had MgADP or ADP.Pi analogs. We report here these findings on the effects of MgADP and MgADP+phosphate analogs to the rigor crossbridges.