• Physical Therapy Korea
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• v.15 no.2
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• pp.73-80
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• 2008

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.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.281-289
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• 2012

Objective: The purpose of this study is to evaluate the potential risk of shoulder muscle at particular working postures in sitting. Background: The cause of shoulder pain needs to be specifically studied in relation with particular shoulder postures to prevent shoulder MSDs in workplace. Method: In this study MVC, fatigue and subjective workload were investigated depending on the change of shoulder posture. An experiment was designed to evaluate the six shoulder muscles at nine shoulder postures including the combination of 30(adduction), 0, 30(abduction) degrees and 60, 90, and 120 degrees of shoulder flexion. Surface electrodes were attached to the middle trapezius, inferior middle trapezius, anterior deltoid, posterior deltoid, serratus anterior and teres major. Thirteen subjects participated in the experiment. Dependent variables were RPE (rating of perceived exertion), MVC(maximum voluntary contraction) and MPF(mean power frequency) shift by EMG (electromyography). Results: The middle trapezius and inferior middle trapezius were not significantly fatigued at all postures. The decline of MPF slope was less than 10% at all postures. The anterior deltoid was significantly fatigued all postures. The decline of MPF slope was more than 10% at all postures. The posterior deltoid was significantly fatigued 30 degrees of adduction and 90 degrees of flexion. And, neutral and 30 degrees of abduction postures were fatigued more than 90 degrees of flexion. The serratus anterior was significantly fatigued except for 30 degrees of adduction and 60 degrees of flexion posture. The teres major was significantly fatigued except for neutral and 60 degrees of flexion, 30 degrees of abduction and 60 degrees of flexion posture. Conclusion: It was found that a certain muscle was fatigued fast at particular posture compared to other muscles, which would mean that a certain shoulder muscle at particular posture could be easily exposed to the risk of musculoskeletal disorders than other muscles. Application: It is expected that the result can be applied to design workplace using shoulder muscles.

• PNF and Movement
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• v.18 no.1
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• pp.107-116
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• 2020

Purpose: To investigate the effects of electromyography (EMG) biofeedback on the muscle activity of the trapezius, shoulder pain, function, and range of motion (ROM) in patients with subacromial impingement syndrome (SAIS). Methods: Sixteen patients (9 males and 7 females) with SAIS participated voluntarily. The main outcome measures were muscle activity of the trapezius, shoulder pain (VAS), ROM, and the shoulder pain and disability index (SPADI). Exercises with EMG biofeedback consisted of shoulder flexion in a standing position, shoulder external rotation in a side-lying position, and shoulder horizontal abduction in a prone position. Post measurements were taken immediately after EMG biofeedback training. Results: Middle and lower trapezius activity, as well as ROM, was significantly increased by exercise with EMG biofeedback (p<0.05). In addition, VAS and SPADI scores significantly decreased post-EMG biofeedback training (p<0.05). Conclusion: EMG biofeedback intervention is an effective exercise for SAIS patients to restore activity of the middle and lower trapezius and to improve pain, shoulder function, and ROM.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.443-448
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• 2013

PURPOSE: In recent years, senior friendly device is growing rapidly because of population aging The study was designed to investigate the effects of table height of electronic bed on upper extremity and trunk EMG in elderly. METHODS: Thirty right-handed elderly without history of neurological and musculoskeletal dysfunction were participated in this study. Three heights of the table (3/3 height, 2/3 height, and 1/3 height between top of the shoulder and olecranon) were provided. During the eating performance, surface electromyography (EMG) was used to measure muscle activity, and electrodes were attached to the deltoid middle fiber, serratus anterior, suprapinatus, upper trapezius, rhomboideus, cervical part of longissimus, thoracic part of longissimus, lumbar part of longissimus on right. One way ANOVA was conducted for the statistical analysis. RESULTS: There were significant differences in deltoid middle fiber, suprapinatus, upper trapezius, rhomboideus, lumbar part of longissimus in the 3 different height of table (p<.05). The deltoid middle fiber, suprapinatus, upper trapezius, and lumbar part of longissimus were significantly increased in higher table than lower table(p<.05). And the rhomboideus was significantly decreased in higher table than lower table(p<.05). CONCLUSION: This study demonstrates that different height of table affect upper extremity and trunk muscle activity. The table height of olecranon is the best for elderly.

• Journal of the Korean Burn Society
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• v.24 no.2
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• pp.64-67
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• 2021

Free flap surgery is commonly used for extensive facial burn. However, free flap surgery requires long operation time and difficult technique. Also, it requires further procedure to prepare the recipient vessels. Hence, applying pedicle flap surgery instead of free flap surgery is effective for patients with facial burn. Among a wide range of pedicle flaps, we performed lower trapezius myocutaneous pedicle flap to patients with third degree facial burn and got satisfactory results without complications. Lower trapezius myocutaneous pedicle flap has a wide arc of rotation so that it can cover middle and lower part of the face. Furthermore, it is thinner than other myocutaneous pedicle flap that can be used for facial reconstruction. Due to these advantages, lower trapezius myocutaneous pedicle can be an attractive option for the reconstruction of facial burn.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.1
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• pp.91-103
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• 2015

Purpose: The purpose of this study was to investigate the effects of home exercise program and exercise program of round shoulder adjustments on the level of trapezius muscle activity and attention capacity for middle school students. Method: The participants in this study were composed of 21 middle school students. We made the students lie on the floor in prone position, then measured the height of their acromion from the floor. We chose participants for our study whose measurement values were over 2.5cm. We divided them into two groups, one is for the experimental group, and the other is for the control group. The experimental group exercised three days a week for 6 weeks, including home training, and the control group didn't exercise. We used EMG to measure the trapezius muscle's activity and used a Stroop test for the measurement of the students' attention capacity. Results: The results of our study are as follows. There was no significant difference between the experimental group and the control group. However, there was a significant difference within the experimental group when comparing pre and post training results for Trapezius muscle activity and attention capacity. Conclusion: We found that correcting round shoulder symptom increases the Trapezius muscle activity and students' attention capacity. Future experiments should investigate with systemical management. Also, we need to increase the frequency of the exercise and participants.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.325-331
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• 2015

Purpose: This study attempts to understand the effect of stabilization exercise of biofeedback scapular on muscle activity and functional evaluation of the upper extremity in stroke patients. Methods: Patients were divided into two groups; a biofeedback scapular stabilization exercise group comprised of 8 patients and a task-oriented training group including another 8 patients, and 30-minute exercise was performed 5 times a week for 8 weeks. Electromyogram was used to measure muscular activity of lower trapezius, deltoid middle, and serratus anterior. Fugl-Meyer Assessment and Manual Function Test were used to evaluate functions of the muscles mentioned. Results: Significant difference was observed in the comparison group before and after exercise in muscular activity of lower trapezius, deltoid middle, and serratus anterior, Fugl-Meyer Assessment, and Manual Function Test. Conclusion: Therefore, we could see that biofeedback scapular stabilization exercise is more effective than task-oriented training in facilitating muscle activation and functional capacity of upper limb.

• The Journal of Korean Physical Therapy
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• v.30 no.3
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• pp.84-89
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• 2018

Purpose: Therapeutic climbing has become very popular today, with it being reported as a new method for preventing and treating orthopedic trauma to the shoulder joint. However, objective studies on its effects on the musculoskeletal system are still lacking. The objective of the present study was to investigate the effects of wall inclination during therapeutic climbing on the muscle activity around the shoulder joint. Methods: In this study, the participants performed movements at three different inclination angles of $0^{\circ}$, $+15^{\circ}$, and $-15^{\circ}$. sEMG was performed to measure the activities of five different muscles around the shoulder joint (biceps brachii, serratus anterior, upper trapezius, middle trapezius, and lower trapezius muscles). Results: Biceps brachii muscle showed a significant increase at $-15^{\circ}$, as compared to $0^{\circ}$ (p<0.01), and the serratus anterior also showed a significant increase at $-15^{\circ}$, as compared to $0^{\circ}$ (p<0.05). Moreover, the middle and lower trapezius muscles also showed a significant increase at $-15^{\circ}$, as compared to $0^{\circ}$ (p<0.001). Compared to $0^{\circ}$, all muscles showed decreased values at $15^{\circ}$, but the differences were not statistically significant (p>0.05). Conclusion: Therapeutic climbing may be a new therapeutic approach that can increase muscle strength and coordination in the sensory nervous system, since it can be used as a tool that promotes active movement by altering wall inclination and causing the user to generate movements according to the existing situation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.1
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• pp.17-25
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• 2016

Purpose: This study was aimed to determine the effects of thoracic spine thrust manipulation on muscle activities of the scapular upward rotators and middle deltoid, active range of motion (AROM), shoulder pain, and rounded shoulder posture in young adults with rounded shoulder. Methods: The subjects were 30 young adults (14 males, 16 females) with rounded shoulder. Thirty subjects were randomly assigned to an experimental (manipulation) and control (placebo) groups of fifteen subjects respectively. The manipulation group received the manipulation (high velocity, low amplitude), which was performed by a physical therapist with the subject in the supine position and with the arms crossed over the chest and hands passed over the shoulders. For the sham group, the same procedure was performed, with the exception that the high-velocity thrust was not applied. Measurements were taken before and after the intervention. Muscle activity of upper and lower trapezius, serratus anterior, middle deltoid was measured using surface electromyography. Visual analog scale (VAS) was used for shoulder pain. Goniometry was used for shoulder abduction active range of motion (AROM). Straight edge was used for supine rounded shoulder posture (RSP) distance. Results: The muscle activity of the upper trapezius, lower trapezius and middle deltoid muscle increased significantly after the intervention (p<.05). However, no significant difference was observed in serratus anterior muscle (p>.05). The VAS was significantly decreased and AROM significantly increased after the intervention (p<.05). The distance of RSP were not significant (p>.05). The control group showed no differences before and after the intervention (p>.05). Conclusion: The results of this study suggest that thoracic spine thrust manipulation can be an effective component of treatment plan to improve pain and function.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.197-204
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• 2016

Objective: The purpose of this study was to analyze the kinematic factors of motion during air pistol shooting. Method: This study aimed to investigate changes in forces during movement and determine the factors that affect changes in force during the first, middle, and last periods of shooting an air pistol. Two ground reaction force systems (force platform), SCATT (a shooting training system), and EMG (electromyogram) to measure the action potentials in the muscles of the upper body were used in this study. Four university air pistol players (age: 19.75 years, height: 175.50 cm, body mass: $69.55{\pm}11.50kg$, career length: $6.25{\pm}6years$) who are training to progress to a higher rank were enrolled. Results: In terms of the actual shooting results, the mean score in the middle section was $42.48{\pm}1.74$ points, higher than those in the first and the last periods when using SCATT. The gunpoint moved 13.48 mm more vertically than horizontally in the target trajectory. With respect to action potentials of muscles measured using EMG, the highest action potentials during the aiming-shooting segments, in order higher to lower, were seen in the trapezius (intermediate region), trapezius (superior region), deltoid (lateral), and triceps brachii (long head). The action potentials of biceps brachii and brachioradialis turned out to be high during grasping motion, which is a preparatory stage. During the final segment, muscle fatigue appeared in the deltoid (lateral), biceps brachii (long head), brachioradialis, and trapezius (intermediate region). In terms of the ground reaction force, during the first period of shooting, there was a major change in the overall direction (left-right $F_x$, forward-backward $F_y$, vertical $F_z$) of the center of the mass. Conclusion: The development and application of a training program focusing on muscle groups with higher muscle fatigue is required for players to progress to a higher rank. Furthermore, players can improve their records in the first period if they take part in a game after warming up sufficiently before shooting in order to heighten muscle action potentials, and are expected to maintain a consistent shooting motion continuously by restoring psychological stability.