• Physical Therapy Korea
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• v.24 no.1
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• pp.61-70
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• 2017

Background: Scapular winging is a prominence of the entire scapular medial border, mainly caused by insufficient activity of the serratus anterior (SA) and imbalance of scapulothoracic muscles. Push-up plus (PUP) exercise has been commonly used to increase SA muscle activity. The facilitation of abdominal muscle may affect scapular muscle activity by myofascial connections. Thus, the sequential activation of the turnk muscles is suggested to facilitate the transition of proper force from upper limb and restore force couple of scapular muscles. The abdominal drawing-in maneuver (ADIM) has been effective in improving activation of the deep trunk muscles during movement. Objects: The aim of this study was to determine the effect of ADIM on the activity of the upper trapezius (UT), lower trapezius (LT), and SA during PUP exercises in subjects with scapular winging. Methods: Fourteen men with scapular winging (determined as a of distance between the scapular medial border and thoracic wall over 3 cm) volunteered for our study. The subjects performed the PUP exercise with and without ADIM. Surface electromyography was used to collect the electromyography data of the UT, LT, and SA. A scapulometer was used to measure the amount of scapular winging. Results: SA activity was significantly greater and scapular winging significantly lower during the PUP exercise with ADIM than during those without ADIM. Conclusion: PUP exercise with ADIM can be used as an beneficial method to improve SA activation and to reduce the amount of scapular winging in subjects with scapular winging.

• The Journal of Korean Physical Therapy
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• v.36 no.2
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• pp.71-77
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• 2024

Purpose: The prolonged use of digital devices has led to the widespread adoption of poor postures, particularly rounded shoulder posture (RSP), associated with shoulder impingement and pain. This study investigates the effects of neuromuscular electrical stimulation (NMES) on RSP in healthy adults. Methods: Thirty adults with RSP were randomly assigned to NMES only, exercise only, or NMES with exercise groups. NMES was applied to the lower trapezius, which was the target muscle in this study, for a total of 2 weeks, 5 times per week, 20 minutes per session. The exercise program included pectoralis minor stretching, wall-slide exercise, dynamic hug exercise with band, and Brugger stretching for upper body with band, which were performed for a total of 2 weeks, 5 times per week, 20 minutes per session. Outcome measures, including the Supine Method (SM) for posture and surface electromyography (EMG) of the lower trapezius for muscle activity, were assessed before the intervention, after 5 sessions, and after 10 sessions. Results: All the groups showed significant changes in the SM and % maximal voluntary isometric contraction (%MVIC) over time (p<0.05). The NMES group had significantly reduced SM at 1 week, while the exercise and combined groups had reduced SM at 2 weeks (p<0.017). All the groups had increased %MVIC at 2 weeks (p<0.017), with no significant differences observed between groups. Conclusion: NMES alone can be as effective as exercise in improving RSP. NMES combined with exercise also showed positive outcomes, thus offering diverse treatment options for this condition.

• Journal of Korean Physical Therapy Science
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• v.26 no.3
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• pp.57-69
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• 2019

Background: The purpose of this study was to compare and analyze the effects of neck and trunk combined exercise program and single exercise on neck angle and neck and shoulder muscle activity. Design: Randomized controlled trial. Methods: In the single exercise group, the basic stretching, head bending and neck bending exercises were performed. The neck and trunk combined exercise group performed torso strength and trunk stability exercises to stabilize the trunk, and then performed the same neck exercise as the single exercise group. The exercise program was conducted 5 days per week for 2 weeks. One-way repeated ANOVA was used to investigate the statistical analysis of neck angle, neck and upper and middle trapezius muscle activity. Results: 1) There was no significant difference in neck angle degree after exercise in neck single exercise group. 2) In the neck and trunk combined exercise, the neck angle degree decreased continuously with the increase of the experimental period and showed a significant difference. 3) In the single exercise group, the muscles which showed significant difference compared to the post-exercise were the right upper, left and right middle trapezius. 4) In the neck and trunk combined exercise group, the right neck muscles showed significant difference after the exercise before the experiment. Conclusion: It was found that the neck and trunk combined exercise was more effective in reducing neck angle and the muscle activity of the subjects with forward head posture was decreased and increased. However, both exercises showed positive effects.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.4
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• pp.65-70
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• 2016

PURPOSE: This study aimed to compare the electromyography (EMG) activity for the middle deltoid (MD) and upper trapezius (UT) muscles in various shoulder abduction angles in patients with adhesive capsulitis (AC). METHODS: A total of 15 subjects participated in the study: 6 without AC (control group) and 9 with AC (AC group). The muscle activities of the UT and MD were measured using EMG during maximal static shoulder abductions in both groups. Each subject performed three repetitions of horizontal abduction at $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$ of the shoulder abduction angle in a sitting position. The measurement data from the middle 3-seconds of the 5-second periods were used. The mean value of three separate sets of measurements was used in the data analysis. For each muscle, independent t-tests were performed to determine group differences. A measured repeated-measures ANOVA was performed using Bonferroni's post-hoc test. RESULTS: The muscle activity of the UT was significantly greater in the AC group; than in the control group (p<.05). The muscle activity of the MD was significantly lower in the AC group; than in the control group (p<.05). The greatest level of muscle activity for both the MD and UT was demonstrated at the $0-60^{\circ}$ and $0-90^{\circ}$ of shoulder abduction angles in the AC group. CONCLUSION: These findings showed that low muscle activation of the MD may contribute to hyperactivity of the UT during shoulder abduction in AC patients.

• Safety and Health at Work
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• v.9 no.3
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• pp.319-325
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• 2018

Background: Prolonged neck flexion during smartphone use is known as a factor of neck pain and alteration of neck muscle activity. Studies on the effects of shoulder taping on neck discomfort and neck muscle responses while texting on a smartphone are still lacking. The aim of this study was to examine the effects of shoulder taping on neck discomfort using a numerical rating scale, and neck muscle activity and fatigue using a surface electromyography during a texting task on a touchscreen smartphone. Methods: Twenty-five healthy adolescents used the dominant hand to perform a 30-minute texting task using a touchscreen smartphone at two separate times under one of the following two conditions: taping across the upper trapezius muscle and no taping. Neck discomfort, normalized root mean square, and normalized median frequency slopes for upper trapezius, cervical erector spinae, and sternocleidomastoid muscles were recorded. Results: The results revealed that shoulder taping provided significantly lower neck discomfort than no taping (p < 0.001). However, shoulder taping did not significantly alter normalized root mean square and normalized median frequency slope values of all muscles when compared with no taping controls. Conclusion: Shoulder taping reduces neck discomfort but does not affect neck muscle activity and fatigue while texting on a touchscreen smartphone.

• PNF and Movement
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• v.22 no.1
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• pp.151-158
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• 2024

Purpose: The present study investigated how variations in diagonal exercises affect shoulder muscle activity, examining changes in neuromuscular activation during scapular and shoulder diagonal patterns of exercises. Furthermore, we explored whether the exercise phase affects muscle activation. Methods: Sixteen asymptomatic male participants were recruited. Four diagonal pattern exercises (scapular anterior elevation, posterior elevation, flexion-adduction-external rotation, flexion, abduction-external rotation), and two exercise phases (concentric and eccentric) were administered. Surface electromyography data were collected. Results: Upper trapezius activity was significantly higher during the concentric phase of scapular posterior elevation exercises compared with the others (p<0.05). The serratus anterior, anterior deltoid, and infraspinatus activities were significantly higher during shoulder diagonal pattern exercises compared with the scapular diagonal pattern exercises (p<0.05). Except for the lower trapezius, muscular activities during the concentric phase were significantly greater compared with the eccentric phase (p<0.05). Conclusion: The current study suggests that the diagonal pattern of exercise may contribute to selective strengthening of the shoulder complex muscles and that the form of exercise should be tailored to the subject. It also suggests that diagonal exercises with concentric contractions tend to be more beneficial than eccentric contractions for overall muscle recruitment, but the effects vary for specific diagonal patterns.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.113-121
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• 2015

PURPOSE: The purpose of this study was to determine the effect of shoulder external rotation on muscle activities of the scapular upward rotators during arm elevation. METHODS: Nineteen healthy subjects with no medical history of shoulder pain or upper extremity disorders were recruited for this study. Electromyography (EMG) was used to measure the muscle activities of the serratus anterior (SA), upper trapezius (UP), lower trapezius (LT) and infraspinatus (IS) muscles during arm elevation. The EMG activities were recorded while the subjects performed $90^{\circ}$ arm elevation with three different arm positions; palm down (PD), neutral position (NP), and palm up (PU). While seated in a chair, the subject was asked to raise the upper extremity in the sagittal plane in random order. Subjects performed $90^{\circ}$ arm elevations in three trials at each arm position. The mean EMG activity normalized by the maximal voluntary isometric contraction was analyzed across three arm positions. Repeated measures one-way ANOVA and the post hoc Bonferroni tests were used to determine the differences in muscle activities among the three arm positions. RESULTS: The EMG activities of the SA and IS were significantly greater in the PU condition than in the other conditions during arm elevation. No significant difference was noted between the NP and PD conditions during arm elevation. CONCLUSION: These results suggest that shoulder external rotation (palm up position) can be used to activate the SA. Therefore, we recommend a scapular protraction exercise in the palm up position for strengthening the SA.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.297-302
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• 2011

Many WMSDs(work-related-musculoskeletal disorders) have been reported in diverse industries and have also attracted much attention in recent years. Neck-related MSD is generally known as one of common WMSDs, especially it happens to workers who are working at the automobile assembly plants and/or shipyards. The awkward posture is considered as a main cause of neck-related MSDs. A neck supporter was developed to prevent neck-related MSDs, and 10 males were recruited to evaluate the newly developed neck supporter by measuring subjective discomfort ratings of whole body, shoulder, neck and neck-muscle activities. Muscle activities from four neck muscle groups(left/right sternocleidomastoid and upper/middle trapezius) were measured while simulating an automobile assembly task. Results showed that the neck supporter help to significantly improve subjective discomfort for whole-body, shoulder as well as neck body parts. The analyses of muscular activities also showed that the activities of left/right sternocleidomastoid muscles were statistically decreased with the neck supporter in this study. The muscle activities of upper/middle trapezius in case of wearing the neck supporter were not significantly different with the muscle activities in case of no-wearing the neck supporter. Overall findings verified that the neck supporter might help to prevent neck-related MSDs based on the current study.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.2
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• pp.71-82
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• 2005

The couple force of the scapular stabilizers for upward rotation that include the upper and lower trapezius, serratus anterior muscles is essential to maintain the stability of shoulder joint. But if there is an imbalance of these muscles, it would occur many problems of shoulder joint. A push-up plus exercise with an unstable support is used in order to increase the muscle activity and stimulate the proprioception of shoulder joint. The purpose of this study was to compare the muscle activity of upper and lower trapezius, serratus anterior muscles and to determine which exercise is more effective when subjects perform push-up plus exercise in the stable support and unstable support. 15 healthy subjects and 15 painful subjects with injury of shoulder joint participated in this study. Surface electromyography data were collected during plus phase of push-up plus exercise. The types of push-up plus exercise were composed of three conditions. Stable type is subjects performed the push-up plus exercise on the fixed support and unstable type 1 is on the sling without shaking and unstable type 2 is on the sling with shaking by tester's manual. The upper and lower trapezius activities of injured group were higher than uninjured group at three measure conditions, but serratus anterior activities were not. The UT/SA ratio of injured group was higher than uninjured group at three measure conditions. The serratus anterior activities were most high at unstable 2 measure in both groups. The UT/SA ratio was most low at unstable 2 measure condition in injured group only. The present result revealed that push-up plus exercise in the unstable support with shaking which took most high serratus anterior activities and most low of UT/SA ratio is optimal cure method that can improve the imbalance of the scapular stabilizer.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.3
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• pp.75-80
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• 2018

PURPOSE: Scapular stability is very important to arm function during activities of daily living. The push-up plus exercise is commonly used to stabilize the shoulder muscles. In the present study, we designed an elastic shoulder band (ESB) that could be used with the push-up plus exercise and studied muscle activities of the serratus anterior (SA) and the lower and the upper trapezius (LT and UT) on stable and unstable support. METHODS: Fifteen healthy people participated in this study. Three muscles were investigated using surface EMG with and without the ESB on stable and unstable support. All subjects performed each trial three times for 7 seconds per set and rested for 30 seconds. Repeated one-way ANOVA was used for statistical analyses. RESULTS: The EMG activity of the SA was significantly different during the push-up plus exercise on stable support with the ESB compared with that on unstable support without the ESB (p<.05). However, there were no differences in the activities of UT and LT on stable and unstable support (p>.05). CONCLUSION: The ESB was effective for the activity of SA during the push-up plus exercise on stable support; therefore, it has the potential for use by people during push-up plus exercises. However, further studies are required to investigate the rehabilitation tools for patients with shoulder instability.