• Physical Therapy Korea
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• v.14 no.2
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• pp.44-52
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• 2007

This study was carried out to compare the muscle activities of the shoulder stabilizers between persons with and without winging scapular during push-up plus exercise (adds the scapular protraction to the general push-up exercise). For this study, eleven males with winging scapular and eleven healthy males were recruited. Surface electromyographic (EMG) activity was recorded from the serratus anterior, upper trapezius, lower trapezius, infraspinatus, and pectoralis major while the subjects performed the push-up plus. Each push-up plus was subdivided into three phases according to the elbow position which was measured using the 3-D motion analysis system: elbow flexion (EF), elbow extension (EE), and shoulder protraction phases (SP). Two-way repeated measure ANOVA (phase ${\times}$ group) were used for statistical analysis. There was significant phase by group interaction only on the EMG composition ratio of the serratus anterior (p>.05). The EMG composition ratio of the serratus anterior was significantly higher in SP than in either EF or EE however, it was not different between winging scapular and normal groups. For both groups, the EMG composition ratio of upper trapezius, lower trapezius, and pectoralis major was significantly different across the phases of push-up plus, but the infraspinatus EMG composition ratio was not. For both groups, in EF and EE phases, the EMG composition ratio of both pectoralis major and serratus anterior were relatively higher than that of other muscles. However, in both groups, the EMG composition ratio of the serratus anterior became much more predominant than that of the pectoralis major. In addition, infraspinatus activated greater than pectoralis major. These results showed that the push-up plus exercise is effective to selectively strengthen the serratus anterior for both individuals with and without winging scapular, but not equally effective for other shoulder stabilizers.

• Physical Therapy Korea
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• v.30 no.2
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• pp.160-168
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• 2023

Background: Individuals with scapular winging have a weak serratus anterior (SA) muscle, and to compensate, the pectoralis major (PM) and upper trapezius (UT) muscles excessively activate, which can cause upper extremity dysfunction. This study aimed to compare the effects of isometric horizontal abduction (IHA) on SA, PM, and UT muscle activity, as well as the SA/PM and SA/UT muscle activity ratios during knee push-up plus (KPP) at 90° and 120° of shoulder flexion. Objects: This study aimed to compare the effects of IHA on SA, PM, and UT muscle activity, as well as the SA/PM and SA/UT muscle activity ratios during KPP at 90° and 120° of shoulder flexion. Methods: This study, conducted at a university research laboratory, included 20 individuals with scapular winging. Participants performed KPP with and without IHA at 90° (KPP90) and 120° (KPP120) of shoulder flexion. SA, PM, and UT muscle activity were measured using surface electromyography. Results: PM activity in KPP90 with IHA was significantly lower than KPP90 and in KPP120 was significantly lower than KPP90. UT activity was significantly greater with IHA than without IHA and at 120° than 90° of shoulder flexion. SA/PM muscle activity ratio was significantly higher in KPP90 with IHA than without IHA and in KPP120 than in KPP90. SA/UT muscle activity ratio was significantly lower with IHA than without IHA. Conclusion: KPP90 with IHA and KPP120 are effective exercises to reduce PM activity and increase SA/PM muscle activity ratio. However, applying IHA in KPP90 also reduces SA/UT muscle activity ratio, implying that it would be preferable to apply KPP120 in individuals overusing their UT muscles.

• Physical Therapy Korea
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• v.21 no.2
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• pp.48-56
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• 2014

The aim of this study to investigate the effects of craniocervical flexion on muscle activities of scapular upward rotators during push-up plus exercise in subjects with winging scapula. Eighteen males with scapular winging were recruited, and each subject performed knee push-up plus and other exercises, in two conditions (craniocervical flexion vs. natural head positions). A surface electromyography (EMG) was used to measure upper trapezius (UT), serratus anterior (SA), and lower trapezius (LT) muscle activity. A paired t-test was used to determine the statistical significance between the different condition with/without applying of craniocervical flexion. UT EMG activity significantly decreased and SA EMG activity significantly increased during knee push-up plus involving the craniocervical flexion compared to the natural head position. However, no significant differences (p>.05) were found in the activity of the LT muscle. The UT/SA ratios with and without craniocervical flexion showed a significant difference (p<.05). These results showed that the knee push-up plus other exercises performed with craniocervical flexion could strengthen the serratus anterior muscle and minimize the activity of the UT muscle.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2008.03a
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• pp.53-53
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• 2008

Twenty-six patients (12 male and 14 female) with symptomatic scapular winging caused by serratus anterior dysfunction were managed with split pectoralis major tendon transfer (sternal head) with autogenous hamstring tendon augmentation from 1998 to 2006. Twenty-five patients had positive results for long thoracic nerve palsy on electromyography. The mean duration of symptoms until surgery was 48 months (range 12~120 months). Four patients had non-traumatic etiologies and twenty-two patients had traumatic etiologies. At the final follow-up assessment for functional improvement, a Constant-Murley score was used. 21 patients were completely evaluated, while 5 patients who had less than 12 months follow-up were excluded. Pain relief was achieved in 19 of the 21 patients, with twenty patients showing functional improvement. The pain scores improved from 6.0 preoperatively to 1.8 postoperatively. The mean active forward elevation improved from $108^{\circ}$ (range $20^{\circ}\sim165^{\circ}$) preoperatively to $151^{\circ}$ (range $125^{\circ}\sim170^{\circ}$) postoperatively. The mean Constant-Murley score improved from 57.7 (range 21~86) preoperatively to 86.9 (range 42~98) postoperatively. A recurrence developed in one patient. Of the twenty-one patients, eight had excellent results, nine had good results, three had fair results, and one had poor results. Most patients with severe symptomatic scapular winging had functional improvement and pain relief with resolution of scapular winging.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.208-208
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• 2009

Eleven shoulders (9 patients) with refractory scapulothoracic dysfunction were treated with scapulothoracic arthrodesis between 2000 and 2006. Refractory shoulder dysfunction included facioscapulohumeral muscular dystrophy in five shoulders (3 patients), refractory scapular winging with long thoracic nerve palsy in one shoulder, scapular winging caused by serratus anterior palsy with trapezius dysfunction in one shoulder, post-surgical thoracic outlet syndrome due to medial clavicle resection in two shoulders, refractory scapular winging with spinal accessory nerve injury in one shoulder, and chronic trapezius rupture caused by cervical spine surgery in one shoulder. The mean active flexion was improved from 82 degrees preoperatively to 112 degrees postoperatively. The mean Constant score was improved from 27.2 points to 68.0 points. Two shoulders (1 patient) that had facioscapulohumeral muscular dystrophy had broken wires due to nonunion, and one patient had a reactive pulmonary effusion. In ten of the eleven shoulders, the patients were satisfied with their results. The scapulothoracic arthrodesis can cause significant pain relief and functional improvement in refractory scapulothoracic and/or shoulder dysfunction. By selecting patients that present with appropriate indications, and using experienced surgical technique through complete preoperative evaluation, we can diminish the complication rate and make good clinical outcomes.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.25 no.1
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• pp.29-36
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• 2019

Background: This study was conducted to investigate the effect of leg lift difference on the serratus anterior muscle and the upper trapezius muscle when a subject with winged scapula performs a scapula protraction exercise in a four-leg crawling posture. Method: Twenty normal adults and 20 subjects with winged scapula participated in the experiment. Surface EMG recordings were collected from serratus anterior muscle and back trapezius muscle during scapula protraction exercises. Scapular winging is measured with the lifting distance of scapula retraction to the back using an electronic digital caliper. In two groups of four-leg crawling posture, the two legs support, the dominant leg lifting, and the non-dominant leg lifting, including the scapula protraction, were performed. To examine the difference between groups in the variance analysis, the Bonferroni correction was used (significance level ${\alpha}=.017$). Statistical significance level ${\alpha}$ was .05. Results: There was a significant difference in serratus anterior muscle and upper trapezius muscle during push-up plus exercise in leg lifting in four-leg crawling posture, but there were no significant differences in muscle activity between serratus anterior muscle and upper trapezius muscle, and there was no significant difference according to the presence or absence of scapular winging. Conclusion: For the shoulder stability of the ipsilateral side with the serratus anterior muscle, the leg-lifting posture is effective in the four-leg crawling, and also when a subject with winged scapula chooses an exercise, lifting the ipsilateral side of leg with scapula protraction exercises at the same time may have a positive effect on scapula dysfunction.

• Annals of Clinical Neurophysiology
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• v.7 no.2
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• pp.124-126
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• 2005

The effect of serratus anterior dysfunction is seen in the scapular winging. We report 2 cases with winging scapula clinically but do not reveal denervation potentials in needle electromyography. Surface myoelectric measurements of median frequency and root mean square values show difference in fatigability and amplitude in affected side.

• Physical Therapy Korea
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• v.27 no.2
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• pp.140-148
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• 2020

Background: Scapular winging (SW) could be caused by tightness or weakness of the periscapular muscles. Although data mining techniques are useful in classifying or predicting risk of musculoskeletal disorder, predictive models for risk of musculoskeletal disorder using the results of clinical test or quantitative data are scarce. Objects: This study aimed to (1) investigate the difference between young women with and without SW, (2) establish a predictive model for presence of SW, and (3) determine the cutoff value of each variable for predicting the risk of SW using the decision tree method. Methods: Fifty young female subjects participated in this study. To classify the presence of SW as the outcome variable, scapular protractor strength, elbow flexor strength, shoulder internal rotation, and whether the scapula is in the dominant or nondominant side were determined. Results: The classification tree selected scapular protractor strength, shoulder internal rotation range of motion, and whether the scapula is in the dominant or nondominant side as predictor variables. The classification tree model correctly classified 78.79% (p = 0.02) of the training data set. The accuracy obtained by the classification tree on the test data set was 82.35% (p = 0.04). Conclusion: The classification tree showed acceptable accuracy (82.35%) and high specificity (95.65%) but low sensitivity (54.55%). Based on the predictive model in this study, we suggested that 20% of body weight in scapular protractor strength is a meaningful cutoff value for presence of SW.

• Physical Therapy Korea
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• v.29 no.2
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• pp.165-170
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• 2022

Background: The serratus anterior (SA) muscle prevents scapular winging (SW) by stabilizing the medial border of the scapula during arm movement. The upper trapezius (UT) and lower trapezius (LT) muscles may compensate for the weak SA muscle in individuals with SW during shoulder flexion. However, there is no study to examine whether compensation by UT and LT occurs in individuals with SW. Objects: This study compared the muscle activities of UT, LT, and SA as well as the SA/UT activity ratio between individuals with and without SW during shoulder flexion with load. Methods: This study recruited 27 participants with SW (n = 14) and without SW (n = 13). Electromyography data of the SA, UT, and LT muscles and SA/UT activity ratio were recorded and analyzed during shoulder flexion with 25% load of the maximal shoulder flexion force. Independent t-test was used to compare the UT, LT, and SA muscle activities and SA/UT ratio between the groups with and without SW; statistical significance was set at α of 0.05. Results: SA activity was significantly lesser in the group with SW than in the group without SW. However, there were no significant differences in the UT and LT activities and SA/UT activity ratio between the two groups. Conclusion: The SA activity was lesser in the group with SW than in the group without SW with 25% load of the maximal shoulder flexion force, but there was no compensatory muscle activity of the UT and LT observed. Therefore, further studies are warranted to clarify the compensatory strategy of scapular stabilization in individuals with SW during shoulder flexion under other heavy load conditions.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.24 no.2
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• pp.29-36
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• 2018

Background: The purpose of this study was to investigate the effect of leg lift difference on serratus and upper trapezius when exercising in a scapula in a prone position, a typical waist stabilization exercise for subjects with a winged scapula. Method: Twenty normal adults and 20 subjects with winged scapula participated in the experiment. The surface EMG recordings were obtained from external oblique muscle and internal oblique muscle during scapula protraction exercise. The presence or absence of winging of the shoulder bone was measured using an electronic digital caliper for the distance the medial border of the scapula is lifted to the rear. In prostrate pier movement posture in both groups, both legs supporting, dominant leg lifting, and non-dominant leg lifting including the scapula protraction were conducted respectively. Results: In the results of comparison between the two groups, the dominant external oblique muscle and the non-dominant internal oblique muscle tended to increase according to the difference of the leg lifting of normal people. In the winged scapula group, internal oblique muscle showed increased muscle activity more than external oblique muscle. Conclusion: It was most effective to exercise with lifting the same position leg for strengthening the same external oblique muscle, and the opposite internal oblique muscle. Also, it is effective to exercise in prone pier movement posture for trunk stability. In addition, internal oblique muscle shows increased muscle activity in subjects with winged scapula. Therefore, appropriate adjustment of external oblique muscle and internal oblique muscle may have a positive effect on scapula dysfunction for trunk stability.