• 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.

• Journal of International Academy of Physical Therapy Research
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• v.6 no.1
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• pp.815-823
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• 2015

This study aimed to examine the most effective exercise method for shoulder joint rehabilitation by comparatively observing activity of shoulder stabilizer muscles during push up and push up plus exercises under diverse stable conditions. The subjects were 20 healthy adults students who went to M university. While the subjects conducted push up and push up plus exercises under diverse stable conditions(a stable surface, a support of 25cm height, a support of 30 cm height and a balance pad), activities of the upper trapezius muscle, pectoralis major muscle, serratus anterior muscle, and triceps brachii muscle were recorded. During push up and push up plus exercises, activities of the stabilizer muscles were higher when the stable condition was changed rather than on the stable surface. In particular, when the support of 30cm height and balance pads were applied, activity of the shoulder stabilizer was highest. There were significant differences in the upper trapezius muscle and triceps brachii muscle during the push up exercise(p<.05) and in the serratus anterior muscle during the push up plus exercise(p<.05). Activities of the shoulder stabilizers were higher when the upper and lower limbs' surface stable conditions were changed than the stable surface. Therefore, when programs for rehabilitation of shoulder joints are applied, provision of diverse stable conditions according to patients' conditions will be effective methods.

• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.157-162
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• 2020

Purpose: This study was to evaluate several tasks performed at a high intensity in terms of their ability to elicit EMG activity in the serratus anterior by comparing the EMG activities of the serratus anterior, upper trapezius, and lower trapezius muscles during six tasks combined shoulder flexion with rotation. Methods: Fifteen healthy males were recruited to this study. Each subject was instructed to assume a sitting position without back support and asked to flex (90° or 120°) the right shoulder and protract the scapula in the sagittal plane with maximal external rotation; to assume a neutral position; or to internally rotate the glenohumeral joint. The EMG data were collected from the serratus anterior (SA), upper trapezius (UT), and lower trapezius (LT) muscles were normalized to maximum voluntary isometric contraction. The UT/LT and UT/SA muscle activity ratios in each task were assessed by calculating the surface EMG. Data were analyzed by two-way repeated-measures analysis of variance, with the level of significance set at p<0.05. Results: The results of this study, shoulder flexion with external rotation resulted in low upper trapezius/serratus anterior and upper trapezius/lower trapezius ratios and a relatively high level of serratus anterior activation. Conclusion: Shoulder flexion with external rotation used herein may be considered as important for clinical interventions aimed at selectively increasing SA strengthen and clinical selection of exercises for improving glenohumeral joint and scapulothoracic control.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.4
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• pp.199-207
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• 2022

Purpose : The purpose of this study is to investigate the effect of shoulder stabilization exercise accompanied by application of a pelvic compression belt on the muscle activity, pain and function of the muscles around the shoulder in subjects with round shoulders. Methods : For the study method, 28 students who were enrolled in K University with a distance of 1 cm or more between the clavicle of the peak and the outer ear path were selected through GPS 400 global postural analysis system measurement. The subjects were randomly assigned to 14 participants in the group wearing a pelvic compression belt and 14 patients in the group not wearing a pelvic compression belt. In all subjects, the muscle activities of the middle trapezius, lower trapezius, and serratus anterior muscles and the shoulder pain disorder index (SPADI) were measured. The intervention was performed 3 times a week for 4 weeks, and the applied intervention was push-up plus and modified prone cobra exercise. The muscle activities of the middle trapezius, lower trapezius, and serratus anterior muscles and SPADI score were compared using dependent t test before and after intervention. Results : In this study, both groups showed that the muscle activity of the middle trapezius, lower trapezius, and serratus anterior significantly increased after the intervention compared to before the intervention. On the other hand, SPADI showed no significant difference. Conclusion : The results of this study showed that muscle activity in the peri-shoulder joint was increased after push-up plus and modified prone cobra exercise in both groups, regardless of whether pelvic compression was applied or not. Therefore, it was found that shoulder stabilization exercise using the pelvic compression belt also contributed to the enhancement of muscle activity in the joints around the shoulder.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.2
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• pp.71-82
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• 2005

The couple force of the scapular stabilizers for upward rotation that include the upper and lower trapezius, serratus anterior muscles is essential to maintain the stability of shoulder joint. But if there is an imbalance of these muscles, it would occur many problems of shoulder joint. A push-up plus exercise with an unstable support is used in order to increase the muscle activity and stimulate the proprioception of shoulder joint. The purpose of this study was to compare the muscle activity of upper and lower trapezius, serratus anterior muscles and to determine which exercise is more effective when subjects perform push-up plus exercise in the stable support and unstable support. 15 healthy subjects and 15 painful subjects with injury of shoulder joint participated in this study. Surface electromyography data were collected during plus phase of push-up plus exercise. The types of push-up plus exercise were composed of three conditions. Stable type is subjects performed the push-up plus exercise on the fixed support and unstable type 1 is on the sling without shaking and unstable type 2 is on the sling with shaking by tester's manual. The upper and lower trapezius activities of injured group were higher than uninjured group at three measure conditions, but serratus anterior activities were not. The UT/SA ratio of injured group was higher than uninjured group at three measure conditions. The serratus anterior activities were most high at unstable 2 measure in both groups. The UT/SA ratio was most low at unstable 2 measure condition in injured group only. The present result revealed that push-up plus exercise in the unstable support with shaking which took most high serratus anterior activities and most low of UT/SA ratio is optimal cure method that can improve the imbalance of the scapular stabilizer.

• The Journal of Korean Physical Therapy
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• v.31 no.4
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• pp.199-203
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• 2019

Purpose: This study investigated the effects of shoulder protraction exercise according to weight by examining the surface electromyography (EMG) amplitude in the serratus anterior (SA), upper trapezius (UT), and pectoralis major (PM) as well as the activity ratio of each muscle. Methods: Twenty three winging scapula subjects participated in the study. The subjects performed scapula protraction at shoulder $90^{\circ}$ flexion and $60^{\circ}$ horizontal abduction with up to four (none, 1kg, 1.5kg, and 2kg) dumbbells in the supine position. The EMG data were collected from the dominant side muscles during a shoulder protraction exercise according to weight in the supine position. One way repeated measures analysis of variance (ANOVA) was used to compare the normalized activities of the SA, UT, and PM and the ratios of PM/SA and UT/SA. Results: The results showed that the activities of both the SA and UT were highest for the shoulder protraction exercise at 2kg in the supine position. The UT/SA ratio also was the lowest for exercise at 2kg. On the other hand, the activities of both the UT and PM/SA ratio were similar under all conditions. Conclusion: These results show that there is a need to selectively strengthen the SA muscle in the case of patients with the shoulder dysfunction. In particular, it is necessary to weigh 2kg when performing shoulder protraction exercises in the supine position to activate the SA muscle in patients with a winging scapula.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.4
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• pp.25-35
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• 2013

Purpose : The purpose of this study was to compare the muscle activities of infraspinatus, serratus anterior, upper trapezius, and triceps brachii in different supporting surface intervals during push-up exercise. Method : Subjects of the study were 18 healthy male students without any orthopedic or neurological injuries including neck and shoulder surgeries and can perform a push-up exercise required for the study. EMG was used to measure the muscle activities of four muscles. Result : There were statistically significant differences of all the muscles in three different supporting surface intervals(p<0.5). Muscle activity of upper trapezius was the highest(MVIC 39.40%) in the narrowest width and the lowest in the widest width. In infraspinatus, muscle activity was the highest(MVIC 36.23%) in the narrowest width and the lowest in the widest width. In serratus, muscle activity is the highest(MVIC 58.04%) in the widest width and the lowest in the narrowest width. In triceps brachii, muscle activity is the highest(MVIC 68.51%) in the widest width and the lowest in the narrowest width. Conclusion : Muscle activities are at the highest with the narrowest width in the upper trapezius and the infraspinatus. In the serratus and triceps brachii, however, muscle activities are at the highest with widest width.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.143-149
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• 2008

The purpose of this study was to investigate the muscle activities of pectoralis major, upper serratus, lat dorsi, anterior deltoid, rhomboids, infraspinatus, and posterior deltoid using Noraxon 8 channels EMG system during T-ball swing in children with Down syndrome. Five Down syndrome, one healthy children, and one baseball adult player were participated in the study. Down syndrome's children showed higher muscle activity than one healthy children and one baseball adult player during address to backswing and backswing to impact swing phase. While Down syndrome's children showed lower muscle activity than one healthy children and one baseball adult player during impact to follow swing phase. The strength of the pectoralis major and upper serratus muscle may help to improve T-ball swing movement during impact to follow swing phase.

• 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.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.940-958
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• 2016

The objective of this study was to analyze the kinematic and kinetic characteristics of two horticultural activities: seed sowing and planting plant. Thirty-one male university students (aged $26.2{\pm}2.0years$) participated in this study. Kinematic factors (movement times, peak velocity, joint angles, and grasp patterns) were assessed using a three-dimensional motion analysis system while the subjects performed the horticultural activities. Kinetic factors (muscle activation of eight upper-limb muscles: the anterior deltoid, serratus anterior, upper trapezius, infraspinatus, latissimus dorsi, biceps brachii, brachioradialis, and flexor carpi radialis) were assessed using surface electromyography. The acts of seed sowing and planting plant were comprised of five tasks which included six types of phases: reaching, grasping, back transporting, forward transporting, watering, and releasing. The movement times, peak velocity, joint angles, and grasp patterns were significantly different across the tasks involved in the horticultural activities. All eight muscles of the upper limbs were utilized during the horticultural activities, and the muscle activation of the serratus anterior was the highest compared to that of the other muscles tested. The kinematic and kinetic characteristics of these horticultural activities showed similar characteristics to reaching and grasping rehabilitation training and daily living activities. The present study provides reference data for common horticultural activities using a kinematic and kinetic analysis.