• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.265-276
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• 2003

The objective of this research is to provide basic data for improving athletic performances, suggesting methods that can be utilized at games and coaching movements in the snatch, by analyzing the level of contribution of muscles to the movements of the snatch lift through three-dimensional imaging and EMG analysis between skilled and unskilled lifters. To this end, three high school students (the skilled group), three middle school student (the unskilled group) were selected; two digital video cameras and electromyography were used. The muscles measured by an EMG include gastrocnemius muscle, biceps femoris muscle, erector spinae, latissimus dorsi muscle, trapezius muscle, and brachioradialis. Based on the Ariel Performance Analysis System (APAS) program, the results of the analysis are summarized as follows. 1. In performing snatch pulls, the skilled lifters were found to simultaneously move the weight centers of the body and the barbell close to vertical, close to the shoulders in the pulling portion; in snatching and grabbing the barbell from a sited position, it was observed that the shorter the time for adjusting to change in the height of the barbell by using rotational inertia, the better it is to perform the movements. 2. The skilled lifters were observed to perform stable and efficient movements in grabbing the bar in a sited position, by moving the barbell and weight center of the body close to vertical and moving the shoulder joint under the bar fast. 3. The results of the EMG analysis of the entire movements from the snatching portion to the portion of grabbing the bar in a sited position show that when the skilled lifters lifted the barbell vertically during the pulling portion, their shoulder joints were extended to put more weight on biceps femoris muscle and brachioradialis; and in snatching and grabbing the bar from a sited position, it was found desirable to increase the myoelectrical activity of erector spinae in order to achieve a balance in the movements of the hip joint between font and rear, as the weight centers of the body and the barbell move higher. On the other hand, the unskilled lifters were found that in response to change in posture, they increase their muscular strength inefficiently in performing the movements throughout the entire lifting process.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.356-362
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• 2012

This study examined the effects of vocalization on upper extremity muscle activity during reaching task in patients with hemiplegia. Thirteen persons with right brain stroke performed reaching to a cup under four concurrent speech conditions of vocalizing the word "Ah" with hemiplegic side. These four conditions are self-vocalization, external vocalization, imaginary vocalization, and no vocalization. The muscle activity(Biceps brachii, Triceps brachii, Middle deltoid, and Upper trapezius) were measured using MP150. Muscle activity was significantly higher under self-vocalization and external vocalization conditions compared to the muscle activity under imaginary vocalization and no vocalization conditions on triceps brachii muscle.(p<0.05). Triceps brachii muscle was highly correlated with biceps brachii muscle(r=0.777, p<0.05). The results suggest that self-vocalization and external vocalization can be used in facilitating upper extremity movements in patients with stroke. When working with patients with right hemispheric stroke, therapists might explore possibilities of using patient's self-speech to enhance the quality of upper extremity movement performance.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.29-41
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• 2020

PURPOSE: The aim of this study was to provide evidence for the treatment of Forward Head and Rounded Shoulder Posture (FHRSP) using posture correction exercises by comparing muscle activity and onset time around the neck and shoulder area during an arm elevation task. METHODS: The subjects were divided into FHRSP (21 persons) and non-FHRSP (19 persons) groups to measure muscle activity and onset time of muscle contraction. Wireless surface electromyography was used to assess the muscle activity and onset time of the right and left sternocleidomastoid (SCM), splenius capitis, anterior deltoid, middle deltoid, serratus anterior, upper trapezius, pectoralis major, and infraspinatus during an arm elevation task. After the pre-measurement, the participants performed the postural correction exercises, and then the post-measurement was conducted. RESULTS: After the posture correction exercises, there were significant differences in the muscle activity and onset time of all muscles in the FHRSP group. The results of the comparison of the muscle onset time during an arm elevation task demonstrated that after the postural correction exercises, the muscle onset time was significantly reduced in the right and left SCM and left splenius capitis, but there were no significant changes in the onset time of other muscles. CONCLUSION: The results of this study help us understand the change in muscle activities and muscle contraction onset time in a person with FHRSP when lifting the arm and suggest the relevant basis to apply the posture correction exercise in clinical settings.

• Journal of Korean Physical Therapy Science
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• v.19 no.4
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• pp.53-59
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• 2012

Background : The purpose of the study was: to investigate muscle activation of upper arm according mouse shape. Methods : Twenty person(mean age : 23. 7) who have healthy condition was participated this study, we collected data of muscle activation using by EMG from upper trapezius(Tr), deltoid middle fiber(De), extensor digitorum(Ed), first dorsal interosseous(Di) during participants was performed click and drag according various mouse. Mouse shape was divided 4 level as follow shape 1 was very small, 2 was small, 3 was moderate, 4 was large. Data was analyzed ANOVA, independent t-test using by SPSS ver18.0. Results : There was significantly difference of muscle activation among each muscle according mouse shape in drag and click. In shape 1, 4, there was significantly difference of muscle activation of Tr, De, Ed between drag and click except Di. In shape 2, 4, there was significantly difference of muscle activation of all muscle between drag and click. Conclusion : We knew that extensor digitroum showed more higher muscle activation than other muscle in drag, first dorsal interoseous showed more higher muscle activation that other muscle in click. We suggest that mouse shape was very important factor in order to prevent skeletal muscular disorder for computer user, and mouse shape can reduce muscle fatigue during computer work.

• Journal of the Ergonomics Society of Korea
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• v.34 no.1
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• pp.11-18
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• 2015

Objective: The aim of this study was to understand the effects of phone weight on the typing performance and muscle recruitment in the neck and upper extremity while typing a text message with dominant hand. The iPhone4 and iPhone5 were compared due to their 28-gram differences in weight. Background: Too much use of a cellular phone can lead the musculoskeletal disorders in the upper extremity. Phone makers tend to make their new models bigger, lighter, faster and smarter. Method: Fourteen healthy volunteers without any history of neuromuscular disorders or ongoing pain who used their smartphone more than one year were recruited. A 112g phone (iPhone5) and a 142g phone (iPhone4) were used for typing the lyric of the Korean national anthem with their dominant hand. Typing duration, the typing error, the perceived fatigue, and preference was investigated. Muscle recruitment and the resting gap of neck (middle trapezius and levator scapula), shoulder (infraspinatus and mid deltoid), elbow (biceps brachii and brachioradialis), thumb (extensor and abductor policis brevis) were collected using surface electromyography. Typing error was counted and typing speed was calculated in characters per min. The data were analyzed using a paired t-test and chi-square (${\chi}^2$) analysis for the effects of phone weight on the typing performance parameters and muscle recruitment. Results: Typing text message with iPhone5 took longer but had less muscle recruitment in brachioradialis, and extensor policis brevis muscles. Lighter weight of iPhone5 made biceps brachii to rest less without increasing the mean %EMG. Conclusion/Application: Findings of this study can be valuable information for phone designers to develop more productive device and for smartphone users to prevent the musculoskeletal disorders in the upper extremities.

• Physical Therapy Rehabilitation Science
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• v.10 no.2
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• pp.147-155
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• 2021

Objective: This study is to investigate the effect of real-time feedback from the therapist on posture, muscle strength, pain of subjects with forward head posture based on a non-face-to-face complex exercise program. Design: Two-group pretest-posttest design. Methods: Thirty healthy men and women in their twenties with forward head posture with a Craniovertebral angle of 52° or less were targeted, the final selection was made as 15 experimental groups who performed the non-face-to-face intervention program while receiving real-time feedback and 15 control subjects who performed the non-face-to-face intervention program without providing feedback. Six of them were eliminated, and a total of 24 were conducted as subjects. All exercise groups performed an exercise program three times a week, 30 minutes each, for a total of two weeks. Before and after exercise, Craniovertebral angle (CVA), CranioRotation angle (CRA), muscle strength, and tenderness threshold were evaluated. Results: Significant differences were shown in both groups in CVA, and tenderness threshold before and after exercise (p<0.05), and CRA, the left middle trapezius muscle strength, only in the experimental group (p<0.05). In the comparison of theamount of change between exercise groups, the group that received feedback on CVA, CRA and tenderness threshold showed a significant change than the group without feedback (p<0.05). Conclusions: As a result of this study, it can be seen that the therapist's real-time feedback is more effective in improving the forward head posture. This requires feedback from the therapist on posture correction during non-face-to-face exercise intervention.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.400-408
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• 2022

Objective: The purpose of this study is to compare EMG activity during horticulture motion and upper limb rehabilitation motion, to confirm whether horticulture motion is suitable for upper extremity rehabilitation of hemiparesis. Design: Three-group cross-sectional design. Methods: The 45 subjects were divided into three groups: hemiparesis (n=15), elderly (n=15) and healthy (n=15). We have recorded EMG signals of six upper limb muscles Upper trapezius (UT), Middle deltoid (MD), Anterior deltoid (AD), Biceps brachii (BB), Triceps brachii (TB), Brachioradialis (BR) during horticultural motions and three upper limb rehabilitative motions. The dependent variables were peak EMG, integral EMG, co-contraction ratio. A two-way repeated measures ANOVA was used to compare the horticultural motion and rehabilitation motion of the three groups. Results: The peak EMG was significantly different in MD, AD, BB, TB according to the motion(p<0.05), and the UT, BB were significant differences according to the group(p<0.05). The integral EMG was significantly different in MD, AD, BB, TB, BR according to the motion(p<0.05), and the BB were significant differences according to the group(p<0.05). The co-contraction ratio was significantly different in TB/BB according of the motion, and there was no difference between the groups. Conclusions: As a result of this study, horticultural motion alone was insufficient for upper arm rehabilitation, and horticultural motion alone was insufficient to induce continuous activity of the forearm.

• Journal of Acupuncture Research
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• v.17 no.3
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• pp.125-139
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• 2000

Study of the fourteen meridians that include name of P'ung(風) point. The results were summarized as follows. 1. Pyongp'ung(秉風) is located middle of the supraspinatous fossa(Small intestine Meridian, 手太陽小腸經). we can cute the local area disease and also use to cure the pathway of the Arm greater yang small intestine which is attacked by P'ung(風) disease. 2. Yep'ung(翳風) is located behind the lobule of the auricle, in the depression between the mastoid process and the mandible(Triple Energizer Meridian, 手少陽三焦經). we can cure the local area disease especially hyper yang disease and also use to cure the pathway of the Arm lesser yang triple energizer which is attacked by P'ung(風) and Yo'l(熱) disease. 3. P'ungmun(風門) is located 1.5 chon beside the lower end of the spine of the second thoracic vertebra(Bladder Meridian, 足太陽膀胱經). we can cure the local area disease and also use to cure the pathway of the Leg greater yang bladder which is attacked by P'ung(風) disease. 4. P'ungbu(風府) is located 1 chon above the middle of natural line of the hair at the back of the head, in the depression below the occiptal protuberance(Governor meridian, 督脈). It connects (Liver meridian, 足厥陰肝經) and Yin Link Vessel(陽維脈). we can cure the rigidity and pain in head and nape which is related Yin Link Vessel(陽維脈). 5. P'ungshi(風市) is located on the lateral part of the thigh, 7 hon above the patella(From the greater trochanter to the knee joint is 19 chon, Gallbladder Meridian (足少陽膽經). we can cure the local area disease(leg, knee, etc). 6. P'ungji(風池) is located Below the occipital bone, in the depression on the outer part of the trapezius muscle(Gallbladder Meridian, 足少陽膽經) on a level with P'ungbu(風府) (Governor vessel, 督脈). we can cure the local area disease and also use to cure the pathway of the Leg lesser yang gall bladder which is attacked by P'ung(風) disease.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.180-190
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• 2016

This prospective pilot clinical trial mainly focuses on developing dual chamber-based assistive cups which are suitable for stroke patients who have struggled with using there affected arms. It is unable to provide motor and sensory enhancement during drinking activities and to examine the feasibility of the devices for acute phase, even for chronic stroke survivors. The stroke patients(n=16; male=8, female=8), in this trial, were provided informed consent to the investigation. All the individuals participated in 1 weeks of training for using cups, randomized over dedicated dual chamber based assistive cups(DC) or placebo-cups(PC) training. All the participants were assessed within 1 week before and after the intervention period. 3-dimensional motion analysis, sEMG(surface electromyography) and 3-dimensional trunk movement were assessed. The result presents DC data group compared with PC showed, they needed lesser ROM(range of motion) at the phase of drinking in shoulder movements and lesser muscle activities on upper trapezius, deltoid middle fiber and triceps brachii muscles, lesser tilting movement on front and back side in drinking phase, the differences were statistically significant(p<.05). Dual chamber-based assistive cup could be one of efficient way to complete ADLs(activities of daily living), especially drinking tasks, and these evidence data may contribute to determine certain rehabilitation policies related to assistive devise usage.

• Physical Therapy Korea
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• v.16 no.2
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• pp.67-76
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• 2009

In order to prevent upper extremity musculoskeletal disorders, effective keyboard selection is an important consideration. The aim of this study was to compare upper extremity muscle activity according to transverse plane angle changes during vertical keyboard typing. Sixteen healthy men were recruited. All subjects had a similar typing ability (rate of more than 300 keystrokes per minute) and biacromion and forearm-fingertip lengths. Four different types of keyboard (vertical keyboard with a transverse plane angle of $60^{\circ}$, $96^{\circ}$, or $120^{\circ}$, and a standard keyboard) were used with a wrist support. The test order was selected randomly for each subject. Surface electromyography (EMG) was used to measure upper extremity muscle activity during a keyboard typing task. The collected EMG data were normalized using the reference contraction and expressed as a percentage of the reference voluntary contraction (%RVC). In order to analyze the differences in EMG data, a repeated one-way analysis of variance, with a significance level of .05, was used. Bonferroni correction was used for multiple comparisons. There were significant differences in the EMG amplitude of all seven muscles (upper trapezius, middle deltoid, anterior deltoid, extensor carpi radialis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris) assessed during the keyboard typing task. The mean activity of each muscle had a tendency to increase as the transverse plane angle increased. The mean activity recorded during all vertical keyboard typing was lower than that recorded during standard keyboard typing. There was no significant difference in accuracy and error scores; however, there was a significant difference between transverse plane angles of $60^{\circ}$ and $120^{\circ}$ with regard to comfort. In conclusion, a vertical keyboard with a transverse plane angle of $60^{\circ}$ would be effective in reducing muscle activity compared with vertical keyboards with other transverse plane angles.