• Journal of Korean Physical Therapy Science
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• v.15 no.3
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• pp.31-41
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• 2008

Purpose : The purpose of this study is to examine the muscle activity of shoulder stabilization according to change of supporting base interval between push-up bend and push-up plus position and is to prevent or treat a shoulder injury by the most effective exercise for rehabilitation. Methods : This study analyzed the muscle activity according to change of supporting base interval between push-up bend and push-up plus movement. The participants without neuromuscular disease were 25 students - 12 males and 13 females - all twenty or over and the surface electrode of EMG attached on pectoralis major, triceps long head, middle trapezius, lower trapezius, serratus anterior and latissimus dorsi. The process has practiced 3 sessions of supporting base interval - narrowing interval, two shoulder interval, broad interval - by push-up bend and push-up plus movement. Result : 1. The muscle activity of pectoralis major was significantly increased according to narrow interval of supporting base on push-up plus movement and was significant difference(p<.05). 2. The muscle activity of biceps was significantly increased according to narrow interval of supporting base on push-up bend movement(p<.05). 3. The muscle activity of middle or lower trapezius was a difference according to change of supporting base on push-up bend and push-up plus movement but was not significant difference. 4. The muscle activity of serratus anterior was significantly increased according to broad interval of supporting base on push-up bend movement(p<.05). 5. The muscle activity of latissimus dorsi was significantly increased according to broad interval of supporting base on push-up bend movement(p<.05). Conclusion : These results lead us to the conclusion that push-up bend exercise have the effect of muscle strength of biceps on narrowing interval, of serratus anterior or latissimus dorsi on broad interval and push-up plus exercise have the effect of muscle strength of pectoralis major on narrowing interval of support base.

• Physical Therapy Korea
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• v.28 no.4
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• pp.256-265
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• 2021

Background: Individuals with scapular winging may have proprioceptive dysfunction which is important for motor control and causes shoulder instability. Reduced serratus anterior (SA) and lower trapezius (LT) muscle activity accompanied by over-active upper trapezius (UT), and pectoralis major (PM) may be contributing factors. Flexi-bar (FB) exercise may be used to increase joint position sense (JPS) and alter the target muscle activities. Objects: This study aimed to investigate the immediate effects of flexi-bar exercise prior to knee push-up plus (FPK) versus knee push-up plus (KPP) on JPS and muscle activity of SA, LT, UT, and PM in subjects with scapular winging. Methods: Eighteen subjects with scapular winging were recruited. JPS was investigated at baseline, after KPP and after FPK. Passive and active JPS errors were calculated by isokinetic equipment. Surface electromyography was used to record muscle activities during KPP and FPK. One-way repeated-measures analysis of variance and post hoc analyses were used to analyze the JPS error measured at baseline, after KPP and after FPK. Paired t-tests were used to compare muscle activities between KPP and FPK. Results: Passive JPS error was significantly decreased after KPP (p = 0.005) and after FPK (p = 0.003) compared to the baseline. Active JPS error was also significantly decreased after KPP (p = 0.016) and after FPK (p = 0.012) compared to the baseline. There was no significant difference in the passive and active JPS errors between KPP and FPK. SA activity during FPK was significantly increased (p = 0.024), and LT activity during FPK was significantly increased (p = 0.006). There were no significant differences in the UT and PM activity. Conclusion: FB might be recommended to immediately improve passive and active JPS and to selectively increase SA and LT muscle activities during KPP in individuals with scapular winging.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.379-385
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• 2014

Purpose: This study was to determine the immediate effects of pulsed magnetic field (PMF) in subjects with upper trapezius (UT) trigger point (TrP). Methods: Fifteen subjects with UT TrP were recruited for the study's PMF group (pain threshold=$2.29kg/cm^2$), and 15 age-, weight-, and gender-matched subjects with UT TrP were recruited for control group (pain threshold=$2.25kg/cm^2$). Pressure algometer was used to measure pressure pain threshold on UT TrP and, cervical range of motion (ROM) inclinometer was used to measure cervical ROM. Surface electromyography was used to record UT, lower trapezius, and serratus anterior muscle activity and relative ratio during scapular plane abduction between pre- and post-treatment. Results: The PMF effectively improved pain threshold and concurrently increased ROM (rotation to the painful side, lateral flexion to the nonpainful side). In addition, the PMF may effectively deactivate UT activity during abduction and the muscle activity ratio between UT and serratus anterior. Conclusion: These findings provided empirical evidence that PMF can be an effective treatment method to reduce pain threshold, to increase cervical ROM, and deactivate UT activity in individuals with TrP.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.3
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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.

• The Journal of Korean Physical Therapy
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• v.25 no.4
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• pp.217-223
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• 2013

Purpose: This study was to investigate whether the two different head postures, natural and ideal head posture, affect head/shoulder posture and muscle activity. Methods: Thirty healthy subjects with the forward head and round shoulder posture were participated in this study. This study utilized a within-subjects design with subjects being positioned into two sitting positions: natural head posture (NHP) and ideal head posture (IHP). Forward head angle (FHA) and forward shoulder angle (FSA) of each subject were measured for assessing the head/shoulder posture and muscle activities of upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) during the forward overhead reaching. Results: There were significant increases in both FHA and FSA after taking IHP, which showed greater angles than in taking NHP. In change of muscle activities, there were significant decreases in both LT and SA after taking IHP, which showed lower activities than in taking a NHP, whereas there was no significant change in UT. Conclusion: These findings demonstrate that postural alterations associated with forward head and rounded shoulder postures could alter scapular kinetics and muscle activity during the forward overhead reaching.

• 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.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.

• PNF and Movement
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• v.17 no.1
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• pp.11-18
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• 2019

Purpose: This study verifies the muscle activity around the amputation site during proprioceptive neuromuscular facilitation (PNF) pattern exercise for the upper extremities on the non-amputated part in upper extremity amputees and provides basic data on effective exercise around an amputation site. Methods: Manual resistance was applied to the PNF upper extremity pattern of the non-amputated part to generate muscle activity around the amputation site. The resistance was adjusted to an intensity that could cause maximal isometric contraction. The muscle activity of the amputation site and the non-amputated part was measured using a surface electromyogram for the upper trapezius, middle trapezius, infraspinatus, serratus anterior, and pectoralis major. Results: During the scapular exercise in the painless range, the amputated side showed significantly lower muscle activity and a lower muscle contraction ratio compared with the non-amputated side. During the PNF pattern exercise in the painless range, the amputated side showed lower muscle activity and a lower muscle contraction ratio compared with the non-amputated side. When the direct scapular exercise of the amputated side was compared with the PNF pattern exercise of the non-amputated side, their muscle contraction ratios were similar. Conclusion: This study confirmed the effectiveness of the PNF pattern exercise of the non-amputated part as a way to indirectly train the injured site with no pain for rehabilitation of patients with serious body injuries, such as amputation. It is necessary to develop effective exercise programs for the rehabilitation of the amputation site based on the results of this study.

• Journal of Convergence for Information Technology
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• v.7 no.4
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• pp.97-103
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• 2017

The purpose of this study was to investigate muscle activity of cervical erector spinae & upper trapezius while using a smartphone according to anterior pelvic tilt & posterior pelvic tilt in sitting position. & we also want to obtain basic data necessary for development of IoT devices. Fifteen healthy men & women aged 20-30 were enolled, After anterior pelvic tilt & posterior pelvic tilt in sitting position were adjusted, they used a smartphone for 5 minutes & EMG signal was measured simultaneously. We used median 3 minutes of measured EMG signal. The results of this study were as follows: In the sitting position, the use of smartphone in anterior pelvic tilt had significantly lower %RVC values in both cervical erector spinae (p <.001), left upper trapezius (p <.001) & right upper trapezius (p <.002) in comparison with posterior pelvic tilt. This means that anterior pelvic tilt make vertebrae maintain normal curvature & prevent forward head posture occurred while using a smartphone. It reduces loads around neck & shoulders, so that %RVC value is significantly lowered. In the future, new posture corrected IoT devices with an aspect of pelvic tilt should be developed.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.1
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• pp.53-60
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• 2024

PURPOSE: The study aimed to analyze the effect of pillow height on upper trapezius and sternocleidomastoid (SCM) muscle activity and overall human body comfort to determine the optimal pillow height. METHODS: The study included 32 healthy college students, of both genders, who provided prior consent. It examined three pillow heights (flat, 6cm, 12cm) and measured the upper trapezius and SCM muscles using ultrasonography, myotone, and electromyography(EMG). Muscle activation, thickness, and fatigue were assessed. RESULTS: The study found significant differences in muscle thickness and muscle tone based on the pillow heights (flat, 6cm, and 12cm) with a p < .05. The SCM and upper trapezius muscles were thinnest at a pillow height of 6cm. Muscle tone in the SCM was lower at both 6cm and 12cm pillow heights. Post-hoc measurements showed significant differences in both the SCM and upper trapezius muscles thickness at the 6cm pillow height (p < .05). Also, significant differences in muscle tone were observed only in the SCM, particularly between the 6cm and 12cm pillow heights. CONCLUSION: The ultrasonography and myotone measurements showed a significant difference in muscle thickness and muscle tension, both of which were above 6cm, while there was no difference in muscle activation. Based on the strong correlation between muscle tension and muscle thickness with pillow height, this study concluded that the human body feels comfortable with a 6cm pillow height. Therefore, it is recommended to use a pillow height of 6cm when lying in a supine position.