• Journal of the Korean Society of Physical Medicine
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• v.10 no.1
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• pp.1-7
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• 2015

PURPOSE: The aim of this study was to investigate the effects of distal movement on shoulder muscle activation during diagonal pattern of exercises. METHODS: Seventeen healthy male participants volunteered to participate. Five muscles of shoulder were investigated during standing performance of diagonal shoulder exercises with and without visual trace. Two patterns of the diagonal exercises were used as diagonal 1 flexion and extension (D1F-E), and diagonal 2 flexion and extension (D2F-E). Two way repeated measures analysis of variance was used, which the factor was the presence of distal movement and exercise variations. RESULTS: The average muscle activity values of the lower trapezius and anterior deltoid are higher with the D2F-E, compared to the D1F-E (p<.05). The distal movement effect was observed within included all muscles except the lower trapezius, which the values are significantly greater in exercise with distal movement (P<.05). All significant increase of the muscles during the exercise with distal movement condition showed over 0.9 for the observed power in present study. CONCLUSION: Present result suggested that the diagonal pattern of exercise with distal movement has additional advantages of activating the scapulothoracic muscle as well as glenohumeral muscles. In addition, the D2F-E exercise pattern is effective for activating lower trapezius and anterior deltoid muscles.

• The Journal of Korean Physical Therapy
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• v.34 no.1
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• pp.6-11
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• 2022

Purpose: This study investigated the muscle activity of the lower trapezius (LT) during three different shoulder flexion exercises. Methods: Twenty-three subjects between 20 and 25 years of age were enrolled. The subjects were asked to perform three different shoulder flexion exercises: 1) shoulder flexion in prone (SFP), 2) shoulder flexion in push-up with a swiss ball (SFPUS) and 3) shoulder flexion in a quadruped position with a swiss ball (SFQPS) in random order. The muscle activity of LT during each shoulder flexion exercise was measured by using surface electromyography. The muscle activity of LT was compared using one-way analysis of variance (ANOVA) and Bonferroni post hoc test among three different shoulder flexion exercises. The statistical significance level was set at α=0.01. Results: The muscle activity of LT was significantly different among three different shoulder flexion exercises (SFP, SFPUS, and SFQPS). The LT muscle activity with SFQPS exercise was greater than SFP and SFPUS exercises (p<0.01). There was no significant difference in LT muscle activity between SFP and SFPUS exercises (p>0.01). Conclusion: The LT muscle activity was greater during SFQPS than SFP and SFPUS. Therefore, SFQPS exercise can be recommended for selectively activation of LT muscle.

• Journal of Korean Physical Therapy Science
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• v.30 no.3
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• pp.14-22
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• 2023

Background: This study was to investigate the relationship between scapular downward rotation ratio (SDRR), lower trapezius (LT) muscle, and rounded shoulder angle (RSA) on each side in subjects with scapular downward rotation syndrome (SDRS). Design: Cross-sectional Study Methods: Fifteen subjects have participated in this study. The RSA and SDRR were assessed using a tape measure in standing posture. The RSA was computed by the angle made by two lines: one was the distance between the root of the scapula and the acromion, and the other was the distance between the acromion and the horizontal line in the root of the scapula. The SDRR was computed by two horizontal lines: one was the distance between the mid-line and root of the scapula, and the other was the distance between the mid-line and inferior angle of the scapula. LT muscle strength was performed in a prone position by the hand-held dynamometer. Results: There was a positive correlation between SDRR and LT strength in the less affected sides (r=.59; p=.02), however, there was no correlation between RSA and LT strength in the more affected sides (p>.05).

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.211-217
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• 2019

This study is designed to reduce worker fatigue, improve efficiency and provide a functional working environment based on previous studies that pain occurs in the shoulder area, especially the upper trapezius muscle, when the keyboard height is not appropriate. In this study, the height of the keyboard is four, the height of the elbow and desk is the same height, the height of the desk is 3cm lower than the elbow, the height of the desk is 6cm high, and the height is 9cm high. When working on the keyboard, the wrist and forerunner were organized into four groups of 10 people so that the height was different for each group. When the height of the keyboard is given in various ways compared to the height of the elbow of the subject, it is verified whether there is a difference in the RMS (Root Mean Square) of the upper trapezius muscle. The results of this study showed that the muscle activity of the upper trapezius muscle cap was significant only in the left and right keyboard height -4cm, 0cm, +4cm, +8cm group, but the difference in muscle activity was not significant in the rest group. The first study will require a study of the control of the factors affecting the tension of the subjects, the measurement of muscle activity against various muscles, and whether the length of the shoulder and fingertips of the subject affect muscle activity according to the keyboard type.

• Physical Therapy Korea
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• v.19 no.1
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• pp.46-55
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• 2012

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 ${\pm}1$ 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.

• Physical Therapy Rehabilitation Science
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• v.10 no.4
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• pp.503-511
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• 2021

Objective: This study compared pain, muscle power (MP), muscle thickness (MT), and normalized position of the scapula (POS) between general physical therapy and general physical therapy with strengthening exercises of the lower trapezius in patients with rounded shoulder and chronic neck pain. Design: Randomized controlled trial. Methods: The participants were 30 patients of W hospital in Gangnamgu, Seoul, with rounded shoulders who were diagnosed with chronic neck pain. Rounded shoulder was defined as a distance between the surface and acromion of >1 inch in the supine position. The participants were assigned to an experimental group (n=15) and a control group (n=15). The experimental group completed four types of strengthening exercises program for 15 minutes, twice weekly, for a total of 5 weeks. Soft tissue mobilization (STM), cervical extension flexion rotation (CEFR), and physical modality were also performed in both groups. Results: The degree of pain was assessed using the numerical rating scale (NRS), MP was measured a handheld dynamometer, MT was measured by ultrasound, and POS was measured using a tapeline. Significant between-group differences were observed in VAS, MP, MP, and POS. Significant changes were observed in the experimental group for VAS, MP, MT, and POS. Conclusions: Based on the results of this study, it was indicated that lower trapezius strengthening exercises performed together with general physical therapy was significantly improved in pain, MP, MT, and POS in patients with rounded shoulder and chronic neck pain compared to when general physical therapy was performed alone.

• PNF and Movement
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• v.10 no.3
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• pp.1-6
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• 2012

Purpose : The purpose of this study was to examine activities of the scapular stabilizers during push-up plus and PNF backward rocking exercises. Methods : 9 subjects performed randomly push-up plus and PNF backward rocking exercises in four point kneeling. The activities of 4 scapular stabilizing muscles were compared between push-up plus and PNF backward rocking exercises. Results : PNF backward rocking exercise showed significantly higher lower trapezius and lower serratus anterior activations compared to push-up plus exercise. Push-up plus exercise showed significantly higher middle serratus anterior activation than PNF backward rocking exercise. Conclusion : PNF backward rocking exercise facilitates the lower trapezius and serratus anterior activations compared to push-up plus exercise.

• 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.

• PNF and Movement
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• v.20 no.2
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• pp.215-222
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• 2022

Purpose: The purpose of this study was to compare the effects of passive scapular upward rotation and posterior tilt and active scapular posterior tilt on the muscle activity of the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA). Methods: Fifteen healthy subjects performed general arm elevation, arm elevation with passive scapular upward rotation and posterior tilt, and arm elevation with active scapular posterior tilt. For active scapular posterior tilt, the subjects were trained in this movement using visual biofeedback and a motion sensor. During each arm elevation condition, electromyography was used to measure the muscle activity of the UT, LT, and SA. The measured data were analyzed using a one-way repeated ANOVA. Results: LT muscle activity was significantly increased during arm elevation with active scapular posterior tilt compared to both general arm elevation and arm elevation with passive scapular upward rotation and posterior tilt (p < 0.05). SA muscle activity was greater during arm elevation with passive scapular upward rotation and posterior tilt than during general arm elevation (p < 0.05). There was no significant change in UT muscle activity among the tested arm elevation conditions (p > 0.05). Conclusion: Performing arm elevation with active scapular posterior tilt and performing arm elevation with passive scapular upward rotation and posterior tilt may be useful strategies for increasing muscle activation of the LT and SA, respectively.

• Physical Therapy Korea
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• v.13 no.4
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• pp.39-46
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• 2006

The purpose of this study was to determine the effects of slump sitting postures on the masticatory, neck, shoulder, and trunk muscles associated with work-related musculoskeletal disorders (WRMD). Eleven healthy adults (age, $23.3{\pm}2.7$ yrs; height, $174.0{\pm}4.1$ cm; weight, $61.4{\pm}6.6$ kg) participated in this study. The participants were free of injury history and neurologic deficits in the masticatory, neck muscles and upper extremities at the time of participation. The subjects were asked to perform erect and slump sitting postures under the guidance of physical therapists. The surface electromyography (EMG) was recorded from the anterior temporalis, masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique, gluteus maximus muscles of 11 adults as they performed visual terminal display work, which are known as the weakened and tightened muscles owing to WRMD. The recorded signals were averaged and normalized to the mean amplitude of the EMG signal obtained during submaximal reference voluntary contractions. The results of study were as follows: The masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique muscles significantly differed in the slump sitting posture (p<.05). The muscle activities of the serratus anterior, middle trapezius muscle, and external abdominal oblique were significantly lower and that of the masseter, upper trapezius, L3 paraspinal muscles were significantly higher. Further research is needed to assess the motor control problems and the function of the deep muscles in posture stability of patients with WRMD.