• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.157-162
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• 2020

Purpose: This study was to evaluate several tasks performed at a high intensity in terms of their ability to elicit EMG activity in the serratus anterior by comparing the EMG activities of the serratus anterior, upper trapezius, and lower trapezius muscles during six tasks combined shoulder flexion with rotation. Methods: Fifteen healthy males were recruited to this study. Each subject was instructed to assume a sitting position without back support and asked to flex (90° or 120°) the right shoulder and protract the scapula in the sagittal plane with maximal external rotation; to assume a neutral position; or to internally rotate the glenohumeral joint. The EMG data were collected from the serratus anterior (SA), upper trapezius (UT), and lower trapezius (LT) muscles were normalized to maximum voluntary isometric contraction. The UT/LT and UT/SA muscle activity ratios in each task were assessed by calculating the surface EMG. Data were analyzed by two-way repeated-measures analysis of variance, with the level of significance set at p<0.05. Results: The results of this study, shoulder flexion with external rotation resulted in low upper trapezius/serratus anterior and upper trapezius/lower trapezius ratios and a relatively high level of serratus anterior activation. Conclusion: Shoulder flexion with external rotation used herein may be considered as important for clinical interventions aimed at selectively increasing SA strengthen and clinical selection of exercises for improving glenohumeral joint and scapulothoracic control.

• The Journal of Korean Physical Therapy
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• v.28 no.2
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• pp.88-94
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• 2016

Purpose: The purpose of this study was to compare therapeutic climbing exercise and general isometric exercise in patients with shoulder impingement syndrome. Methods: Among 20 adults, study subjects were arbitrarily classified into an experimental group of 10 and a control group of 10. The control group performed general isometric exercise (ISE) and the experimental group performed therapeutic climbing exercise (TC) (3 sets, 3 times per week for 8 weeks). To evaluate the effects of exercise, subjects were evaluated using a Disabilities of the arm, shoulder and hand score (DASH), a goniometer for range of motion, and shoulder activity measured serratus anterior, upper trapezius, and lower trapezius. Independent and paired t-test were used for comparison of the effect between groups. Results: DASH scores showed a significant decrease in both groups after 8 weeks of treatment (p<0.001) and significant difference was observed between the TC groups (p<0.01). Flexion and abduction were significantly increased after 8 weeks of treatment in the ISE group (p<0.001) and flexion, abduction, external and internal rotation were significantly increased after 8 weeks of treatment in the TC group (p<0.001). Serratus anterior and lower trapezius activity were significantly increased after 8 weeks of treatment (p<0.001) and upper trapezius activity was not significantly increased after 8 weeks of treatment in the ISE group (p>0.05). Serratus anterior, lower trapezius, and upper trapezius activity were significantly increased after 8 weeks of treatment in the TC group (p<0.001). Conclusion: Scapular stabilizing exercise using a therapeutic climbing exercise increases range of motion and decreases DASH, and increases activity of shoulder muscles in patients with impingement syndrome.

• Physical Therapy Korea
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• v.19 no.2
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• pp.12-19
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• 2012

The purpose of this study was to assess the influence of scapular alignment on the electromyographic (EMG) activity of the trapezius in people with a short pectoralis minor muscle. For the study, we recruited 15 volunteers who had positive results for short on a pectoralis minor muscle length test. We measured the EMG activity of the upper, middle and lower trapezius muscles. The participants lifted their dominant arm to ear level with the thumb up toward the ceiling in the prone position on a table with the shoulder at a flexion angle of 180 degrees and a horizontal abduction angle of 120 degrees. Scapula was manually aligned by an experienced physical therapist prior to arm lift for the scapular alignment condition. A paired t-test was used to compare the effects of scapular alignment on the EMG activity of the trapezius muscles. The EMG activity of the lower trapezius muscle was significantly increased during the test with the scapular alignment compared to that without scapular alignment (p<.05), while the upper trapezius and middle trapezius exhibited no significant difference between the two conditions (p>.05). The findings of this study suggest that a scapular alignment may alter the recruitment of the lower trapezius muscle during arm lifting in the prone position in people with a short pectoralis minor muscle.

• Annals of Clinical Neurophysiology
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• v.6 no.2
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• pp.85-91
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• 2004

Background: Needle electromyography (EMG) and motor evoked potential (MEP) of the genioglossus (tongue) are difficult to perform in evaluations of the craniobulbar region in amyotrophic lateral sclerosis (ALS). Therefore, we investigated the yields of needle EMG and MEP recorded from the upper trapezius, since it receives innervation from the lower medulla and upper cervical cord. Methods: Needle EMG and MEP of the upper trapezius were obtained in 17 consecutive ALS patients. The needle EMG parameters recorded included abnormal spontaneous activity and motor unit action potential (MUAP) morphology. An upper motor neuron (UMN) lesion was presumed when either response to cortical stimulation was absent, or the central conduction time was delayed (>mean+2SD). Results: Of the five patients with bulbar-onset ALS, four had abnormalities in the upper trapezius and four in the tongue by needle EMG. In contrast, of the 12 patients with limb-onset ALS, 11 had abnormalities in the upper trapezius, and only five in the tongue. When MEP was performed, it was found that three of the five patients with bulbar symptoms and three of the six patients with isolated limb involvement had abnormal MEP findings. Conclusions: Electrophysiological studies of the upper trapezius are more sensitive those of the tongue in patients without bulbar symptoms. Thus, needle EMG and MEP of the upper trapezius are alternative tools for assessing bulbar and rostral neuraxial involvement in the diagnosis of ALS.

• The Journal of Korean Physical Therapy
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• v.30 no.6
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• pp.218-223
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• 2018

Purpose: The purpose of this study was to evaluate the impact of active vibration exercise on the neck pain, disability index, and muscle activity of patients with forward head posture. Methods: A total of 24 patients were randomly assigned to an experimental group or a control group (n=12 each). The experimental group performed active vibration exercise using a flexi-bar for 20 minutes a day, five times a week for four weeks. The study measured patient neck pain using a visual analog scale, neck pain related disability using the neck disability index, and muscle activity using electromyography. Results: The intragroup comparison showed significant differences in the visual analog scale score, neck disability index score and upper trapezius, lower trapezius and serratus anterior muscle activity values among patients in the experimental group. The intergroup comparison showed that differences in the visual analog scale score, neck disability index score and upper trapezius, lower trapezius and serratus anterior muscle activity values in the control group. Conclusion: This study showed that active vibration exercise was effective in improving the neck pain, disability index, and muscle activity of patients with forward head posture.

• Physical Therapy Korea
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• v.21 no.2
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• pp.67-73
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• 2014

The aim of this study was to compare the activity of the upper trapezius (UT) and serratus anterior (SA) and ratio of UT to SA during shoulder elevations. Ten subjects with UT pain (UTP) and 13 subjects without UTP participated in this study. Subjects with a UTP of over five in a pain intensity visual analogue scale (0-10 ㎝) for more than 2 months and latent myofascial trigger points (MTrPs) in the UT muscle were included in the UTP group. Electromyography (EMG) data of UT and SA at 1st and 10th elevations were analyzed. Two-way repeated analyses of variance were used to compare the EMG activity of UT and SA and the ratio of UT to SA during shoulder elevations between groups with and without UTP. There was a significant increase in UT/SA ratio in the group with UTP compared to the group without UTP (p=.01). The activity of UT and SA measured at the 10th elevation was significantly greater than that in the first elevation (p<.05). The activity of SA was significantly greater in the group without UTP than the group with UTP (p=.03). However, there was no significant difference between groups with and without UTP in terms of UT activity (p=.28). These results indicate that UTP may have relevance to the increased muscle activity ratio of UT to SA during shoulder elevations.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.4
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• pp.19-27
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• 2020

Purpose : We aimed to investigate the effect of cranio-cervical flexion exercises(CCFE) with visual feedback(VF) on the muscle activity of the upper trapezius in forward head posture (FHP) and whether deficits in proprioception affect the changes in muscle activity. Methods : Twenty subjects with FHP were assigned to one of 2 groups according to deficits in proprioception. The muscle activity of the upper trapezius during arm movement under three exercise conditions (resting, CCFE, and VF + CCFE). Repeated-measures analysis of variance was used to compare differences in muscle activity according to the exercise conditions between the groups and to analyze the interactions between groups and conditions. Results : Significant differences were observed in muscle activity according to the exercise condition (p<.05), with no significant differences between the groups. The muscle activity of the upper trapezius was significantly different between the resting and VF +CCFE conditions (p<.05), with no significant difference between the resting and CCFE conditions (p>.05). Conclusion : The results of this study showed that the CCFE combined with VF are an effective intervention for FHP to train deep muscles selectively. In addition, the loss of proprioceptive sensation is not related to changes in muscle activity during exercises.

• Physical Therapy Korea
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• v.10 no.1
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• pp.37-50
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• 2003

The purpose of this study was to compare visual analogue scale (VAS), pain threshold (PT), $%RMS_{RVC}$, and EMG gaps before and after applying transcutaneous electrical nerve stimulation (TENS) on the upper trapezius muscle at the patients with myofascial pain syndrome (MPS). The subjects were 4 men and 10 women composed of both the inpatients and outpatients who were diagnosed as MPS at Wonju Medical Center. VAS and PT measurements were performed to assess the subjective pain level. The reference voluntary contraction (RVC) test was performed for 15 seconds for normalization on the bilateral trapezius muscle using surface electromyography (sEMG). After 3-minute resting time, the EMG signal was recorded while performing a typing activity for 2 minutes and then TENS was applicated with a comfortable intensity for 10 minutes. The EMG activity of the upper trapezius muscle was recorded during typing for 2 minutes. The results of study were as follows: 1) VAS score was significantly decreased on the more painful side after treatment, however, it was not significantly different on the less painful side. 2) PT was increased after treatment on both sides, however, it was not significantly different between before and after the TENS application. 3) The EMG activity during typing was significantly decreased after treatment, and 4) The EMG gaps were significantly increased after TENS treatment compared to before it. Consequently, the study showed that TENS was effective in decreasing VAS, $%RMS_{RVC}$, and in increasing EMG gaps. The EMG gap analysis could be a useful method to measure pain in patients with MPS in the upper trapezius.

• 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 Korea
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• v.17 no.4
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• pp.8-15
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• 2010

This study was designed to investigate the effect of different hand positions on scapulothorcic muscle activities during push-up plus exercises. Fourteen healthy males performed push-up plus exercises under three conditions (neutral, $90^{\circ}$ internally rotated, and $90^{\circ}$ externally rotated hand positions), during which the activities of the serratus anterior, pectoralis major, and upper trapezius muscles were recorded using surface electromyography. The statistical significance at three different hand positions was tested by repeated one-way ANOVA. The mean activities of the serratus anterior increased and the mean activities of the pectoralis major decreased in the order of neutral hand position, internally rotated hand position, and externally rotated hand position. There was a significant difference during push-up plus between neutral and externally rotated hand positions as well as in the serratus anterior/pectoralis major activity ratio (p<.0.5). However, no significant differences were found in the activity of the upper trapezius muscle or the serratus anterior/upper trapezius activity ratio. We suggest that the push-up plus exercise performed in the externally rotated hand position could a beneficial strategy for selective strengthening of the serratus anterior muscle, while minimizing the activity of the pectoralis major muscle.