• 한국운동역학회지
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• 제22권2호
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• pp.193-199
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• 2012

The purpose of this study was to investigate the activities of the serratus anterior (SA) and upper trapezius (UT) muscles during scapular protraction exercise with a dumbbell. Twenty-one healthy subjects with no medial history of shoulder pain or upper extremity disorders were recruited for this study. Subjects performed scapular protraction at $90^{\circ}$ and $130^{\circ}$ shoulder flexion with a dumbbell in supine and standing positions. The activities of the SA and UT were measured via surface electromyography (EMG) during 4 scapular protraction exercises. A 2 (angle) ${\times}$ 2 (position) repeated-measures analysis of variance (ANOVA) was used to compare the normalized activities of the SA and UT and the UT/SA ratio. The results showed that activities of both the SA and UT were the highest for the scapular protraction exercise at $130^{\circ}$ shoulder flexion in the standing position. However, the UT/SA ratio was the lowest for the exercise at $90^{\circ}$ shoulder flexion in supine position. Therefore, for selective activation of the SA muscle, we recommend performing the scapular protraction exercise with a dumbbell in the supine position at $90^{\circ}$ shoulder flexion.

• 대한물리의학회지
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• 제8권1호
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• pp.41-48
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• 2013

PURPOSE: This study was to determine the effect of the plane of movement (sagittal plane vs. scapular plane) and shoulder flexion angle ($90^{\circ}$ vs. $130^{circ}$) during scapular protraction exercises in healthy subjects by investigating the elecromyographic (EMG) activities of the serratus anterior (SA), upper trapezius (UT), and pectoralis major (PM). METHODS: Twenty-one healthy subjects participated in this study. Subjects performed maximal scapular protraction at the $90^{\circ}$ or $130^{\circ}$ shoulder flexion angles in the sagittal or scapular planes. Surface EMG was recorded from the SA and UT, and PM muscles. Dependent variables were examined by 2 (plane) ${\times}$ 2 (angle) repeated measures of analysis of variance (ANOVA). RESULTS: Significantly increased EMG activities in the SA and UT were found during scapular protraction exercise at the $130^{\circ}$ shoulder flexion angle in the sagittal and scapular plane. Also, EMG activity of the PM significantly decreased at the $130^{\circ}$ shoulder flexion angle in the sagittal plane and the $90^{\circ}$ and $130^{\circ}$ shoulder flexion in the scapular plane. CONCLUSION: we recommend scapular protraction exercise at the $90^{\circ}$ shoulder flexion in the sagittal plane to selectively strengthen the SA muscle with limitation of upper trapezius activity and at the $130^{\circ}$ shoulder flexion in the scapular plane to selectively strengthen the SA muscle with limitation of pectoralis major activity.

• 한국전문물리치료학회지
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• 제24권4호
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• pp.11-19
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• 2017

Background: Methods for exercising serratus anterior (SA) and upper trapezius (UT) muscles are important for the recovery of patients with various shoulder disorders, yet the efficacy of closed or open kinetic chain exercises have not yet been evaluated. Objects: The purpose of this study was to compare the activation of the SA and UT muscles during scapular protraction considering both closed and open kinetic chain exercises. Methods: Thirty subjects were randomly divided into experimental groups (closed kinetic chain exercise) and control groups (open kinetic chain exercise) in which scapular protraction was performed at $90^{\circ}$ or $125^{\circ}$ shoulder flexion. Electromyographic activity data were collected from the SA and UT muscles per position and exercise method. Results: Separate mixed 2-way analysis of variance showed significant differences in the activation of the SA (F1,28=6.447, p=.017) and the UT (F1,28=35.450, p=.001) muscles between the groups at $90^{\circ}$ and $125^{\circ}$ shoulder flexion. Also, the SA/UT ratio measures at $90^{\circ}$ and $125^{\circ}$ shoulder flexion significantly differed between the groups (F1,28=15.457, p=.001). That is, the closed chain exercise was more effective than open chain exercise for strengthening the SA muscle and controlling the UT muscle, $125^{\circ}$ of shoulder joint was more effective than $90^{\circ}$. Conclusion: The findings suggest that scapular protraction with shoulder $125^{\circ}$ flexion at the closed kinetic chain exercise may be more effective in increasing SA muscle activation and decreasing UT muscle activation as well as increasing the SA/UT ratio than open kinetic chain exercise.

• 대한정형도수물리치료학회지
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• 제25권1호
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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.

• 한국전문물리치료학회지
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• 제28권3호
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• pp.194-199
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• 2021

Background: The scapulo-thoracic musculatures including serratus anterior (SA), upper trapezius and lower trapezius can provide shoulder stability and functional shoulder movement. Objects: The muscle activities of upper and lower SA were compared during three different scapular protraction exercises in healthy individuals in sitting position. Methods: Twenty-five healthy subjects were participated. Electromyography device was used to measure muscle activity of upper and lower SA and trapezius muscles. Each subject was asked to perform three different scapular protraction exercises (scapular protraction [SP], SP with self-resistance [SPSR], SPSR with hand-exerciser [SPSRH]) in random order. One-way repeated measures analysis of the variance and a Bonferroni post hoc test were used. Results: The muscle activity of lower SA muscle was significantly different among three conditions (SP vs. SPSR vs. SPSRH) (p < 0.01). The lower SA muscle activity was significantly greater during SPSRH compared to SP and SPSR, which required joint stability more than SP and SPSR (p < 0.01). Conclusion: SPSRH exercise can be recommended to facilitate the muscle activity of lower SA. In addition, the intramuscular variation in the upper and lower SA during scapular protraction exercise is required to consider the effective rehabilitation.

• 대한정형도수물리치료학회지
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• 제27권3호
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• pp.37-46
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• 2021

Background: The increase in the activity of the upper trapezius (UT) muscle and decrease in the activity of the serratus anterior (SA) and lower trapezius (LT) muscle produce an abnormal scapulohumeral rhythem. Therefore, the SA is the focus of therapeutic exercise protocols for the rehabilitation. This study aimed to compare the activity of the muscles according to resistance levels during protraction exercise. Methods: Thirteen healthy 20 to 30 years old male and female subjected participated in the study. All subjects performed the scapular protraction exercise with the weights of 0, 5, and 10kg, combined with horizontal shoulder abduction and adduction. The electromyography data of the SA, UT, and pectoralis major (PM) during the exercise were recorded using surface electrodes. The ratios of PM/SA and UT/SA were calculated. Repeated one-way ANOVA was used to determine the statistical significance. Results: There was a significant difference in the muscle activity of the SA and PM (p<.05). Specifically, SA had the highest activity and PM had the lowest activity at an abduction resistance 10kg (p<.01). There was a significant difference in the ratios of UT/SA and PM/SA (p<.05). The ratio of PM/SA was the lowest at the abduction resistance of 10kg (p<.01). Conclusion: According to this study, for the selective activation of the serratus anterior, protraction exercises should be applied as a method of adding resistance to protraction and horizontal abduction.

• Physical Therapy Rehabilitation Science
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• 제9권2호
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• pp.98-104
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• 2020

Objective: The shoulders are a particularly an important body part for elite boxers. The purpose of this study was to investigate the characteristics of the upper trapezius (UT), infraspinatus (IS) muscle tone, pain, and isokinetic muscle function of shoulder movements such as external rotation, internal rotation, protraction, and retraction according to the scapular position of elite boxers of the Korean national team. Design: Cross-sectional study. Methods: Using the double square method, the scapular position was measured and divided into the forward scapular position group (n=8) with a measurement distance of 135 mm or more, and the normal scapular position group (n=10) with a measurement distance of less than 135 mm. Through the numeric rating scale of the subject, the pain value displayed during movement was measured. The muscle tone of the subjects' UT and IS were measured. The isokinetic muscle function of ER, IR, protraction, and retraction were measured using isokinetic exercise equipment. Results: The results of this study showed statistically significant differences when comparing muscle tone of the UT and IS, shoulder pain, isokinetic function of ER and IR, protraction, and retraction according to scapular position (p<0.05). Conclusions: The findings of this study were that shoulder muscle tone, pain, and isokinetic muscle function were affected according to the scapular position of elite boxers. In the future, this information may be a useful indicator when studying the effects of medium and long-term intervention in elite boxers who possess these characteristics.

• The Journal of Korean Physical Therapy
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• 제30권1호
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• pp.8-13
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• 2018

Purpose: The present study was to investigate effects of scapular position and pain on a trunk stabilization exercise with gym ball for patients with arthroscopic rotator cuff repair. Methods: Subjects were patients after 2 weeks of rotator cuff repairs. Subjects were randomly assigned to conservative treatment group (CTG, n=10) or trunk stabilization with gym ball group (SBG, n=10), and participated one of those groups for 2 weeks. Measurements about pain and scapular position were assessed in before and after treatment programs. Results: Pain reduced in both rest and night in SBG compared to CTG. In the case of scapular position, decreased scapular retraction (increased protraction) was found in CTG and vice versa in SBG. Reduced scapular anterior tilting was also found on SBG. Conclusion: The present study showed that early performed trunk stabilization with gym ball could bring a scapular alignment that increases subacromial space and reduces pain. This suggests early trunk stabilization with gym ball programs to restore shoulder functions for patients with rotator cuff repair.

• 대한정형도수물리치료학회지
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• 제24권2호
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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.

• The Journal of Korean Physical Therapy
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• 제24권3호
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• pp.229-234
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• 2012

Purpose: The purpose of this study was to compare a control group and an experimental group, consisting of arthroscopic shoulder surgery patients who had received acute rehabilitation treatment and who were to perform scapular stabilization exercise. Methods: Sixteen subjects were studied. The control group, n=8, received instruction for basic physical therapy intervention. An experimental group, n=8, received instruction for doing scapular stabilization exercise (protraction, retraction, elevation, depression) 10 times, 6 times per week. To evaluate the effects of exercise, subjects were evaluated using a joint position sense of shoulder (JPS), disability of the arm, shoulder index (DASH), shoulder pain and disability index (SPADI). Results: Participants showed after the intervention, both groups saw their JPS errors at $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$ significantly decrease relative to before the intervention (p<0.05). Both groups saw their JPS rates at $90^{\circ}$ significantly decrease (p<0.05), with no significant changes in JPS at $30^{\circ}$ and $60^{\circ}$ (p>0.05). SPADI and DASH significantly decrease after the intervention (p<0.05), with no significant decreases before the intervention (p>0.05). The change rates of SPADI and DASH significantly reduced (p<0.05). Conclusion: Low-intensity scapular stabilization exercise is considered effective as a clinical treatment for arthroscopic shoulder surgery patients who receive acute rehabilitation treatment.