• Journal of the Korean Society of Physical Medicine
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• v.14 no.2
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• pp.1-7
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• 2019

PURPOSE: This study was conducted to investigate effects of shoulder adduction load on rotator cuff muscles, including the infraspinatus, during the external rotation exercise of shoulder. METHODS: This study investigated 16 healthy university students from Daegu University. Before the study started, all participants understood the content of this study. They signed an informed consent form. Five electrodes for surface electromyography (sEMG) were attached to their infraspinatus, middle deltoid, posterior deltoid, upper trapezius and pectoralis major. The participants then underwent the shoulder external rotation exercise with the shoulder adduction at three loads (0 mmHg, 20 mmHg and 40 mmHg) that were controlled using a stabilizer Pressure $Bio-feedback^{TM}$ device. The surface electrodes recorded the electromyographic data during the external rotation exercise of shoulder. RESULTS: The infraspinatus was most activated when the shoulder adduction pressure was 40 mmHg during the external rotation exercise of shoulder. The infraspinatus activation significantly increased when the shoulder adduction pressure intensity increased, while the middle deltoid activation and the posterior deltoid activation significantly decreased (p<.05). CONCLUSION: In conclusion, increases in shoulder adduction load intensity during shoulder external rotation exercises can have a positive effect on the infraspinatus, which consists of rotator cuff muscles, with minimal activity in the middle and posterior deltoid.

• Physical Therapy Korea
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• v.29 no.2
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• pp.106-116
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• 2022

Background: Shoulder external rotation exercises are commonly used to improve the stabilizing ability of the infraspinatus. However, during exercise, excessive activation of the posterior deltoid compared to the infraspinatus causes the humeral head to move anteriorly in an abnormal position. Many researchers have emphasized selective activation of the infraspinatus during shoulder external rotation exercise. Objects: This study aims to delineate the optimal exercise method for selective activation of infraspinatus by investigating the muscle activities of the infraspinatus and posterior deltoid according to the four shoulder exercise methods and two forearm positions. Methods: Thirty healthy individuals participated in this study. The participants were instructed to perform shoulder external rotation exercises following four exercise methods: sitting external rotation (SIER); standing external rotation at 90° abduction (STER); prone external rotation at 90° abduction (PRER); side-lying external rotation (SLER), and two forearm positions (neutral, supinated). The electromyography (EMG) signal amplitude was measured during each exercise. Surface EMG signals were recorded from the posterior deltoid, infraspinatus, and biceps brachii. Results: EMG results of the infraspinatus and posterior deltoid in PRER, were significantly higher than that of the other exercises (p < 0.01). The EMG ratio (infraspinatus/posterior deltoid) in SIER was significantly higher than that of the other exercises. EMG activation of the posterior deltoid in SIER, PRER, and SLER was significantly higher in neutral than in supinated (p < 0.01). Furthermore, the EMG of the infraspinatus in SIER was significantly higher in neutral than in supinated (p < 0.01). The EMG ratio (infraspinatus/ posterior deltoid) in SIER was significantly higher in neutral than in supinated (p < 0.05.) Contrarily EMG ratios in PRER and SLER were significantly higher in supinated than in neutral (p < 0.05). Conclusion: The results show that clinicians should consider these exercise methods and forearm positions when planning shoulder external rotation exercises for optimal shoulder rehabilitation.

• Physical Therapy Rehabilitation Science
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• v.8 no.3
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• pp.152-157
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• 2019

Objective: We aimed to investigate differences of range of motion in measuring shoulder internal rotation (IR) and external rotation (ER) resulting from posture change in manual scapular stabilization in prone, hook-lying, sitting, and standing positions in healthy young adults. Design: Cross-sectional study. Methods: This study included healthy young adults who agreed to participate after a thorough explanation about the study purpose and methods. A clinometer was used to measure shoulder rotation. Measurements of shoulder rotation according to postural change were performed in prone, hook-lying, sitting, and standing positions. The repeated measures analysis of variance was used to compare between-group differences in postural change. Results: The lower the posture, the greater the average value of IR angle. In contrast, the higher the posture, the greater the average value of the external rotation angle. In active and passive IR with posture change, there was difference in average value but with no statistical significance. In active and passive ER, there was a statistically significant difference between prone and sitting, prone and standing, hook-lying and sitting, hook-lying and standing, and sitting and standing position (p<0.05). Conclusions: Our findings suggest that postural change should be considered in order to increase the strength or range of motion of the internal and external rotation of the patient's shoulder joint.

• Journal of the Korean Society of Radiology
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• v.6 no.4
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• pp.299-303
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• 2012

Shoulder MRArthrography was performed to get an accurate diagnosis about complex anatomical structure in shoulder joint. We carried out how the changes of anatomical rotations in shoulder joint could bring certain diagnosis effects on MRI images for various shoulder humerus positions; Neutral position, Internal rotation position and External rotation position. In addition, we prepared an aid tool in oder to maintain the right posture of a patient. This aid tool was made by adapting Modeling Design Program. By virtue of this aid, we obtained the following result. Shoulder MR Arthrography by the External rotation position for anatomical structure diagnosis was the most suitable in diagnostic evaluations of important anatomical structures in shoulder joint such as Biceps tendon, Supera-spiatus tendon, Sub-scapularis tendon, Labrum and Sub-acromial space.

• Clinics in Shoulder and Elbow
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• v.18 no.1
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• pp.13-20
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• 2015

Background: The purpose of this study is to assess the range of shoulder motion using an indirect evaluation method without physical examinations of patients based on questionnaires regarding several specific arm postures referenced by patient's own body parts. Methods: Nine criteria of specific shoulder motion including 4 forward flexion, 2 external rotation, and 3 internal rotation were decided as reference position which can represent a certain shoulder motion. Flexion contains postures such as lifting arm to waist-height, shoulder-height, eye-height, and raising arm above head with arm touching ears. External rotation comprises grasping ears and placing hands on back of the head. Vertebral height in internal rotation is determined by calculating the samples' motions, which are holding on to trouser belts, opposite-elbow, and scapula. These postures are included in questionnaires for patients to evaluate the validity and effectiveness of this indirect method. Results: The range of flexion was $77^{\circ}$ ($60^{\circ}$ to $100^{\circ}$), $96^{\circ}$ ($87^{\circ}$ to $115^{\circ}$), $135^{\circ}$ ($115^{\circ}$ to $150^{\circ}$), and $167^{\circ}$ ($150^{\circ}$ to $175^{\circ}$) when arms go up to waist, shoulder, eye, and high vertically. Range of external rotation was $39.6^{\circ}$ ($30^{\circ}$ to $50^{\circ}$) when grasping ears and $69.2^{\circ}$ ($60^{\circ}$ to $80^{\circ}$) with the hands on the back of the head. Range of internal rotation was L4 when placing trouser belts, T12 for holding opposite elbow, and T9 for reaching scapula. The mismatch rates of flexion, external rotation, and internal rotation were 11.6%, 9.6%, and 7.8%. Conclusions: The range of shoulder motion using this method is expected to be applied to an established shoulder scoring system which included shoulder motion evaluation item.

• Clinical Pain
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• v.18 no.2
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• pp.76-81
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• 2019

Objective: To examine (1) the degree of reduction of passive range of motion (PROM) on the affected side compared to that on the unaffected side and (2) the degree of increase in PROM following intra-articular corticosteroid injection (IACI) in patients with frozen shoulder. Method: The medical records of 120 patients with frozen shoulder were retrospectively reviewed. PROM of the unaffected and affected shoulder (flexion, extension, abduction, internal rotation, external rotation) was compared, and changes in PROM of the affected shoulder after a single IACI (triamcinolone 20 mg) were evaluated after 12 weeks. Results: At the time of diagnosis, PROM of the affected shoulder was most limited in external rotation, followed by internal rotation, abduction, extension, and flexion, compared to that of the unaffected shoulder. Compared to before IACI, PROM of external rotation demonstrated the greatest increase compared to all the other movements after IACI. Conclusion: Limitation in PROM of the frozen shoulder at the time of diagnosis was greatest for external rotation. Moreover, external rotation experienced the greatest improvement after IACI. Our findings should help to further clarify the clinical characteristics of frozen shoulder, aid in its diagnosis, and allow the prediction of the effects of IACI.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.2
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• pp.219-229
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• 2013

PURPOSE: The purpose of the study was to investigate a influence in Proprioceptive Neuromuscular Facilitation, and self-assisted ROM exercise of shoulder adhesive capsulitis. METHODS: The methods of the study was to investigate a change in range of motion (ROM), an increase in ROM, visual analogue scale (VAS) and disability questionnaire by Proprioceptive Neuromuscular Facilitation, and self-assisted ROM exercise on 32 patients who were diagnosed with shoulder adhesive capsulitis. RESULTS: There was no significant difference between the two groups who were treated in the Proprioceptive Neuromuscular Facilitation and self-assistive ROM exercise group for flexion, extension, internal rotation, external rotation, VAS and disability questionnaire. Both group's flexion, extension, internal ratation, and external rotation levels were significantly different before and after the treatment. And significant statistical decrease in VAS and disability was seen. The extension of the shoulder joint was closely related to external rotation (r=0.84). There was a close relationship between internal rotation and external rotation at the shoulder joint. There was no increased range of extension through the exercise method. However, flexion, extension, internal rotation, external rotation, VAS, and disability questionnaire of Proprioceptive Neuromuscular Facilitation groups were obviously higher than in the self-assisted ROM exercise group. CONCLUSION: Our study suggest that considering Proprioceptive Neuromuscular Facilitation for the patient who has shoulder adhesive capsulitis in clinic.

• Asian Oncology Nursing
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• v.4 no.1
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• pp.62-70
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• 2004

The purpose of this study was to use as a basic data to develop suitable nursing intervention program and decide an appropriate intervention time after assessing shoulder range of motion in postmastectomy from 2 weeks to 3 month. 147 patients are chosen as study subject among patients who were in recovery of 2weeks, 1month, 2months and 3 months after surgical operation which is modified radical mastectomy. Data were collected at oncology medicine local and general surgery local in Seoul National University Hospital from May, 2003 to October, 2003. The range of motion of the shoulder(flexion, extension, abduction, internal rotation, external rotation) were examined. Analysis of data that shoulder range of motion average and standard deviation, percentage of the unaffected side and affected side compare with normal shoulder range of motion. Paired t-test was adopted to analyze the difference between affected side and unaffected side. Conclusion from this study is as following, 1. The most serious problem was external rotation (0.56%) and internal rotation is the next (19.9%) in 5 kinds of shoulder range of motion in 2 weeks after surgical operation 2. There was no difference in internal rotation after post operation 3 months but there were differences and shown to recover more than 90% in flexion and abduction. Also shoulder function incresed in flextion less than 80% and more than 80% in external rotation. As this study finding was shown that shoulder range of motion did not get back perfectly except of internal rotation and extension in point of 3 months after breast cancer surgical operation. External rotation was specially shown the lowest result so it is needed to exercise for improving their physical functioning recovery in postmastectomy patients. And it is suggested to study for helping to postmastectomy patients' physical and psycosocial functions with the early rehabilitation program which is based on these results.

• Clinics in Shoulder and Elbow
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• v.1 no.2
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• pp.186-192
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• 1998

This study was performed to evaluate the influences of the passive glenohumeral rotation on the scapulothoracic motion. We took anteroposterior radiograms of the right shoulders including the thoracic vertebrae with supine position in 10 normal male adults, at 0 degree abduction, 45 degrees abduction and 90 degrees abduction in scapular plane and in neutral rotation, maximal internal rotation and maximal external rotation in each abduction view. The scapulothoracic motion was measured as the distances between the vertical line drawn from the spinous process of the 7th cervical vertebra and the inferior and superior angles of the right scapula respectively. At 0 degree abduction, the distances were not changed in internal rotation relative to neutral rotation, but decreased significantly in external rotation, that is, the scapula shifts medially on external rotation. At 45 degrees abduction, the distances were increased significantly only in internal rotation, that is, the scapula shifts laterally on internal rotation. At 90 degrees abduction, the scapula rotated laterally on internal rotation and medially on external rotation. In conclusion, when a physician examines the rotation of the shoulder joint, he cannot exclude the scapulothoracic motion just by examining the patient with supine position. And we concluded that the rotatory movement of the shoulder is not solely contributed to the glenohumeral motion.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.2
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• pp.2071-2076
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• 2020

Background: Based on the understanding of the muscle activation relationship between the infraspinatus and posterior deltoid muscles to according to the angle of motion during external rotation on glenohumeral joint, effective shoulder joint strengthening exercise for the prevention and rehabilitation of shoulder injury due to muscle strength imbalance can be performed by achieving the ideal muscle activity ratio during exercise. Objectives: To compare and analyze the muscle activation changes and activity ratio of the infraspinatus and posterior deltoid muscles according to the glenohumeral external rotation angle. Design: Quasi-randomized trial. Methods: The study included 48 healthy male and female adults who provided informed consent for participation in the study. All the subjects performed isometric glenohumeral external rotation by setting the angle of motion to 30°, 45°, and 60° using a 5 kg resistance weight pulley. On surface electromyography, the differences in muscle activation and activity ratio between the infraspinatus and posterior deltoid muscles were investigated. Results: A significant difference in muscle activation was found in the comparison between the infraspinatus and posterior deltoid muscles according to the glenohumeral external rotation angle (P<.05). The muscle activation levels of the infraspinatus and posterior deltoid muscles were highest at the external rotation angles of 30° and 60°, respectively. The muscle activity ratio between the infraspinatus and posterior deltoid muscles also showed a significant difference (P<.05) and was highest at the shoulder external rotation angle of 30°. Conclusion: The findings of this study suggest that muscle activity is the highest at the shoulder external rotation angle of 30° in healthy individuals.