• Physical Therapy Korea
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• v.27 no.1
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• pp.38-44
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• 2020

Background: Posterior shoulder tightness, which is a problem mainly seen in patients with shoulder impingement syndrome, disrupts the scapulohumeral rhythm between the humerus and scapulae. Objects: The aim of this study was to compare the effects of joint mobilization and stretching on shoulder muscle activity and internal rotation range of motion (ROM) of the glenohumeral joint in patients with impingement syndrome with posterior shoulder tightness. Methods: The research subjects included 22 in-patients with impingement syndrome with posterior shoulder tightness. They were randomly divided into two groups: one group (12 patients) was treated with joint mobilization and the other group (10 patients) was treated with stretching for the posterior shoulder tightness. Each treatment was performed five times a week for two weeks, and there were 15 sessions for each treatment. The ROM of the internal rotation and muscle activities of shoulder joint were evaluated pretest and posttest in each group. Electromyography data were collected from the upper, middle, and lower trapezius and serratus anterior during shoulder abduction of 90°, 120°, and 150°. Results: Both the joint mobilization and stretching groups showed significant decreases in muscle activity in the upper, middle, and lower trapezius on the posttest (p < 0.05). There was a significant difference in serratus anterior at 150° (p < 0.05), but there was no significant difference between group in post-hoc analysis (p > 0.025). The internal rotation ROM was significantly increased in the stretching group compared to that in the joint mobilization group (p < 0.025). Conclusion: This study found that both joint mobilization and stretching for posterior shoulder tightness were effective in muscle activity during arm abduction, also in order to increase internal rotation ROM of shoulder joint, stretching was effective in patients with impingement syndrome with posterior tightness.

• Physical Therapy Korea
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• v.26 no.2
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• pp.61-68
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• 2019

Background: Forward head posture (FHP) is a postural alignment of the cervical vertebrae that leads to increased gravitational load on cervical segmental motions. The overhead arm lift test assesses the ability to actively dissociate and control low cervical flexion and move the shoulders through overhead flexion. Objects: The purpose of this study was to explore muscle activities in the upper trapezius (UT), serratus anterior (SA), sternocleidomastoid (SCM), and lower trapezius (LT) alongside changes in head position during the overhead arm lift test in individuals with FHP. Methods: Fifteen subjects with forward head posture and fifteen subjects with normal subjcects were enrolled in this study. The patients performed the overhead arm lift test, and muscle activities of the UT, SCM, SA, and LT were measured using surface electromyography and by evaluating changes in head position. Independent t-tests were used to detect significant differences between the two groups and Cohen's d was calculated to measure the size of the mean difference between the groups. Results: The FHP group demonstrated significantly increased muscle activity of the UT ($32.46{\pm}7.64$), SCM ($12.79{\pm}4.01$), and LT ($45.65{\pm}10.52$) and significantly decreased activity in the SA ($26.65{\pm}6.15$) than the normal group. The change in head position was significantly higher in the FHP group ($6.66{\pm}2.08$) than the normal group. Effect sizes for all parameters assessed were large between the two groups. Conclusion: The subjects with excessive FHP displayed were unable to fix their heads in position during the overhead arm lift test. The overhead arm lift test can thus be used in clinical settings to confirm control of the neck in these subjects.

• Physical Therapy Korea
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• v.24 no.1
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• pp.86-96
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• 2017

Background: Scapular dyskinesis is characterized by altered scapular position and motion. Specifically, excess activation of the Upper trapezius (UT) combined with decreased Lower trapezius (LT) and Serratus anterior (SA) have been observed. The Standard push-up plus exercise (SPP) is considered as a therapeutic exercise for increasing SA activity and maintaining the scapular kinematics. In addition, Using the Sling surface can lead to higher muscle activity. However, the advantage of an unstable surface has been uncertatin. Objects: To compare the activation of the UT, LT, and lower serratus anterior (LSA) muscles during various push-up plus exercises with and without sling in subjects with scapular dyskinesis. Methods: Total 18 male subjects with scapular dyskinesis were recruited. The UT, LT, and LSA electromyographic activities and the UT/LSA and UT/LT EMG activity ratios were measured during three push-up plus exercises with and without sling. Two-way repeated of analysis of variance was used to determine the statistical significance. Results: The UT activity was significantly lower in all postures without sling than that with sling. In addition, the LSA activity was significantly greater without than with sling, and significantly large in SPP, Low back supported push-up plus (LSPP), and Quadruped push-up plus. Additionally, the UT/LSA and UT/LT activity ratios were lower in SPP and LSPP without sling than with the other four push-up plus exercises. Conclusion: The push-up plus without sling were considered to decrease UT and increase LSA activity compared with exercises with sling. Furthermore, SPP without sling seems to be a more effective exercise for increasing LSA activity and lowering the UT/LSA and UT/LT activity ratios in scapular dyskinesis subjects.

• Physical Therapy Korea
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• v.25 no.3
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• pp.1-11
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• 2018

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.

• Physical Therapy Korea
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• v.29 no.2
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• pp.117-123
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• 2022

Background: Push-up are effective exercises for shoulder stability. Previous studies have documented the effects of support plane and hand position and width on muscle activities during a push-up. Objects: This study aimed to investigate the changes in muscle activities in the upper extremity when performing the standard and the knee-flexed push-up with different hand shapes. Methods: A total of twenty-six healthy males participated in this study. Three different hand shapes (finger abduction, finger adduction, and fists) and two types of push-up posture (standard and knee-flexed push-up) were set as the independent variables. Electrograms were used to measure the muscle activity of the upper trapezius (UT), triceps brachii (TB), pectoralis major (PM), and serratus anterior (SA). Each participant performed the randomly assigned push-up to the sound of the metronome. The mixed-effect linear regression model was used to detect the changes in muscle activities after changing the hand shape and push-up posture. Statistical significance was set at α = 0.05. Results: The UT muscle activity was statistically significantly higher when performing push-up with fists than finger abduction (p = 0.035) or finger adduction (p = 0.044). During the standard push-up, the muscle activity in all muscles was that the push-up with fists showed the highest muscle activity compared to the finger abduction (p < 0.01) and finger adduction (p < 0.01). Regardless of the shape of the hand, UT had the lowest muscle activity compared to other muscles (p < 0.001). In contrast, the SA muscle had the highest muscle activity among four muscles during the standard push-up. Conclusion: Based on the results of this study, we suggest hand shape is related to the difficulty level of push-up either in the standard or the knee-flexed push-up, especially in the push-up with fists. In addition, knee push-up can be recommended as shoulder muscle-strengthening exercises for individuals with low shoulder muscle strength.

• Journal of Industrial Convergence
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• v.21 no.4
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• pp.123-131
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• 2023

The purpose of this study was to investigate difference of activity of scapular stabilizer muscles among push-up, knee push-up and wall push-up exercise. Eight male college students were recruited as participants without any history of shoulder or pathology. The results showed that serratus anterior, anterior deltoid, infraspinatus were higher muscle activities than other scapular stabilizer muscles during push-up exercise and muscle activity of standard push-up exercise was higher muscle activity than that of Knee and Wall push-up exercise. Also, We know that knee push-down exercise was more effective than wall push-down exercise for scapular stabilization.

• Physical Therapy Korea
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• v.23 no.2
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• pp.57-66
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• 2016

Background: For the treatment of forward head posture (FHP) and forward shoulder posture, methods for strengthening scapular retractors and deep cervical flexors and stretching pectoralis and upper cervical extensors are generally used. No study has yet assessed whether suboccipital release (SR) followed by cranio-cervical flexion exercise (CCFE) (SR-CCFE) will result in a positive change in the shoulders and neck, showing a "downstream" effect. Objects: The purpose of this study was to investigate the immediate effects of SR-CCFE on craniovertebral angle (CVA), shoulder abduction range of motion (ROM), shoulder pain, and muscle activities of upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) and LT/UT and SA/UT muscle activity ratios during maximal shoulder abduction in subjects with FHP. Methods: In total, 19 subjects (7 males, 12 females) with FHP were recruited. The subject performed the fifth phase of CCFE immediately after receiving SR. CVA, shoulder abduction ROM, shoulder pain, muscle activities of UT, LT, and SA, and LT/UT and SA/UT muscle activity ratios during maximal shoulder abduction were measured immediately after SR-CCFE. A paired t-test and Wilcoxon signed-rank test were used to determine the significance of differences in scores between pre- and post-intervention in the same group. Results: The CVA (p<.001) and shoulder abduction ROM (p<.001) were increased significantly post-versus pre-intervention. Shoulder pain was decreased significantly (p<.001), and LT (p<.05) and SA (p<.05) muscle activities were increased significantly post- versus pre-intervention. The LT/UT muscle activity ratio was increased significantly post- versus pre-intervention (p<.05). However, there was no significant change in UT muscle activity and SA/UT muscle activity ratio between pre- and post-intervention (p>.05). Conclusion: SR-CCFE was an effective intervention to improve FHP and induce downstream effect from the neck to the trunk and shoulders in subjects with FHP.

• Physical Therapy Korea
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• v.20 no.3
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• pp.27-35
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• 2013

The aim of this study was to compare the electromyographic (EMG) activity levels of the scapular upward rotators [upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA)] and other scapular muscles [posterior deltoid (PD), levator scapulae (LS), and infraspinatus (IS)] during isometric lower trapezius exercises. Twenty males with no medical history of shoulder pain or upper extremity disorders were recruited for this study. EMG activity was recorded from the UT, LT, SA, PD, LS, and IS while subjects performed three different exercises: Prone arm lift (PAL), Backward rocking diagonal arm lift (BRDAL), Modified Prone Cobra (MPC). One-way analysis of variance (ANOVA) was used to determine any significant differences among the three exercises. A lower relative activation of UT, LT, and SA was seen with the MPC than with the other exercises (p<.05). The relatively lower activation of the UT identified, the MPC exercise as the preferred choice for preferential strengthening the LT (p<.05). However, a higher activation in the PD, LS, and IS occurred with the MPC than with the other exercises (p>.05). The recruitment pattern of synergist varied depending on the exercise posture. These findings suggest that exercise posture is an important factor in the selection of strengthening exercise for weak muscle.

• Physical Therapy Korea
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• v.27 no.2
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• pp.93-101
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• 2020

Background: For performing various movements well, cooperation between the muscles around the scapula and shoulder has been emphasized. Taping has been widely used clinically as a helpful adjunct to other physiotherapy methods for shoulder pathology and dysfunction treatment. Previous studies have evaluated the effect of taping techniques using dynamic tapes on shoulder function and pain. However, no study investigated the electromyographic (EMG) changes in the shoulder muscles. Objects: This study aimed to investigate the effect of the upper limb offload taping technique using a dynamic tape on EMG activities of the upper trapezius (UT), lower trapezius, serratus anterior (SA), and middle deltoid (MD) muscles during scaption plane elevation. Methods: A total of 26 healthy subjects (19.85 ± 6.40 years, male = 20) volunteered to participate in this study. The subjects were instructed to perform scaption elevation with and without dynamic taping on the shoulder. Shoulder elevation strength tests were performed at 100%, 75%, 50%, and 25%, for the maximal isometric contraction force. Results: There were statistically significant interaction effects between the taping application and shoulder scaption elevation force in EMG activities in the UT (p < 0.05) and MD (p < 0.05). EMG activities in the UT showed significant increases in 50%RVC (reference voluntary contraction, p < 0.05) and 25%RVC (p < 0.01). Furthermore, the EMG activity of the SA significantly increased in 50%RVC (p < 0.01) and 25%RVC (p < 0.01) after dynamic taping. For the MD, the EMG activity level significantly decreased in 100%RVC (p < 0.05). Conclusion: These results indicated that upper limb offload dynamic taping application affects the muscle activities of some shoulder muscles depending on different scaption elevation strength levels. Therefore, we suggest that the upper limb offload dynamic taping can be applied to the shoulders when patients need middle deltoid inhibition or upper trapezius facilitation, such as patients with shoulder impingement syndrome.

• Physical Therapy Korea
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• v.22 no.4
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• pp.17-26
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• 2015

The purpose of this study was to investigate the effects of visual electromyography (EMG) biofeedback on the EMG activity of the lower trapezius (LT), serratus anterior (SA), and upper trapezius (UT) muscles, the LT/UT and SA/UT EMG activity ratios, and the scapular upward rotation angle during scapular posterior tilting exercise (SPTE). Twenty-four subjects with round-shoulder posture participated in this study. The EMG activities of the LT, SA, and UT were collected during SPTE both without and with visual EMG biofeedback. The scapular upward rotation angle was measured at the baseline, after SPTE without visual EMG biofeedback, and after SPTE with visual EMG biofeedback. The LT, SA, and UT EMG activities, and the LT/UT and SA/UT EMG activity ratios were analyzed by paired t-test. The scapular upward rotation angle was statistically analyzed using one-way repeated analysis of variance. If a significant difference was found, a Bonferroni correction was performed (p=.05/3=.017). The EMG activities of LT and SA significantly increased, and the EMG activity of UT significantly decreased during SPTE with visual EMG biofeedback compared to SPTE without visual EMG biofeedback (p<.05). In addition, the LT/UT and SA/UT EMG activity ratios significantly increased during SPTE with visual EMG biofeedback compared to SPTE without visual EMG biofeedback (p<.05). Significant increases were found in the scapular upward rotation angle after SPTE without and with visual EMG biofeedback compared to baseline (p<.017), and no significant differences were observed in the scapular upward rotation angle between SPTE without and with visual EMG biofeedback. In conclusion, SPTE using visual EMG biofeedback may be an effective method for increasing LT and SA activities while reducing UT activity.