• Journal of Digital Convergence
• /
• v.10 no.1
• /
• pp.399-405
• /
• 2012

The purpose of this study was to compare the shoulder stabilizer muscle activity during a push up plus on a different conditioning surface. Eighteen healthy volunteers were tested. Surface EMG was recorded from the upper trapezius(UT), pectoralis major(PM), and serratus anterior(SA) using surface differential conditions. Measurements were performed for 7 days. The mean root mean square (RMS) of EMG activity was calculated. A one-way repeated measures analysis of variance was performed to compare RMS normalized values. The UT and PM did not show significant differences of electric activation amplitude in relation to different surface conditions(p>.05). However, the SA showed greater mean electric activation amplitude values on the push up plus exercise on a upper and lower unstable surface(p<.05). These results suggest that to improve SA EMG activity is more useful when performed on a upper and lower unstable surface conditions than on a stable surface conditions.

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

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

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.8
• /
• pp.749-754
• /
• 2015

The purpose of this study is to conduct a comparative analysis of the right shoulder's muscle activity when lifting ipsilateral and contralateral legs during the Push Up Plus (PUP) exercise, which is a typical shoulder stabilizing exercise, and to provide effective data for a shoulder stabilization exercise. Upper trapezius, lower trapezius, levator scapula, supraspinatus, infraspinatus, deltoid posterior, serratus anterior and pectoralis major, which are eight main muscles of a shoulder, were analyzed for the left and right leg lifting by using an electromyogram (EMG). The study revealed that the muscle activities of the right shoulder's upper trapezius, levator scapula, supraspinatus, serratus anterior and pectoralis major were higher when lifting an ipsilateral (right side) leg, compared to lifting a contralateral (left side) leg. Therefore, lifting an ipsilateral leg can be an effective method for enhancing the maneuverability (mobility) of the right shoulder when lifting a single leg.

• Journal of The Korean Society of Integrative Medicine
• /
• v.1 no.3
• /
• pp.51-62
• /
• 2013

PURPOSE : This study of 20 healthy male subjects by applying various scapular stabilization exercise to compared Serratus anterior and lower trapezius is change in ultrasound images. METHOD : Thirty healthy subjects voluntarily participated in this study. Ultrasound imaging was recorded from the increasing the activity of Serratus anterior(SA) and Lower trapezius(LT) muscles using Push-up plus, Wall slide, Scapular plane shoulder elevation with resistance exercise. Thickness changes in the Serratus anterior(SA) and lower trapezius(LT) muscles between the relaxed and contracted states in the each exercises. To identify statistical significance, one-way ANOVA with repeated measures was used with the significance level of .05. RESULT : The results of this study were as follows : 1) There were statistically significant difference in thickness changes in the Serratus anterior(SA) and lower trapezius(LT) muscles between the relaxed and contracted states in the each exercises. 2) The Scapular plane shoulder elevation with resistance is more effective to Strengthening in the scapular stabilization muscles than Push up-plus and Wall slide. CONCLUSION : The Scapular plane shoulder elevation with resistance may be used to effectively that patient with various shoulder pain.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1232-1234
• /
• 2003

The push pull forward converter is a very suitable circuit for low output voltage, high output current applications with a wide input voltage range. This converter can be miniaturized by integrate magnetic components such as the output inductor, the transformer and the input inductor. We considered of the efficiency for the push pull forward converter. Developed the push pull forward converter rating are of $36{\sim}72V$ input and 3.3V/30A output. In this converter. the efficiency was measured by 76.4% at full load and 82.95% at half load. The maximum efficiency is up to 83.% at 200kHz, 11A output.

• Journal of Korean Physical Therapy Science
• /
• v.26 no.3
• /
• pp.8-14
• /
• 2019

Purpose: This study was conducted in order to influence the muscle strength of an serratus anterior, deltoid and triceps brachii depending on the left or right leg lifting during push up in the crawling position. Design: Cross-sectional study. Methods: 20 subjects participated in the study, Subjects perform 10 Push-up holding the right-left leg lifting in the crawling position according to the EMG sound that comes out every 3 seconds. Six muscles were measured in the right and left deltoid, triceps brachii and serratus anterior. Results: There was no significantly different in deltoid and triceps brachii activity in the lifted position compared to the unlifted position, but there was significantly difference in serratus anterior. Conclusion: In the crawling position, push up with the leg lifting increased the muscle activity of the serratus anterior Serratus anterior was higher than other muscle activity.

• Journal of the Korean Arthroscopy Society
• /
• v.2 no.2
• /
• pp.135-140
• /
• 1998

From 1989 to 1994, authors have reconstructed the posterior cruciate ligament(PCL) in 51 knees with an autogenous central one-third of the patellar tendon by transtibial two tunnel technique, but there were not a few cases of unfavorable results. So from January 1995, we have reconstructed the PCL deficient knees by "modified tibial inlay technique" to avoid the grafted tendon abrasion at the posterior opening of the tibial tunnel(killer turn). Purpose of this study was to compare the results of two surgical techniques and what its advantages and disadvantages are. We could follow up 39 cases of transtibial two tunnel techique group(group A) more than one year, average being 23.7 months and 21 cases of modified tibial inlay technique group(group B) more than 12 months, average being 14.7 months. The clinical results were evaluated by the OAK knee scoring system ($M{\ddot{u}}ller$'s criteria) and the posteror stress roentgenography (push view) with Telos stress device compared with the uninjured knees. The arthroscopic second-look findings were also evaluated. In group A : The $M{\ddot{u}}ller$'s knee score was average 80.1 points, the posteror displacement in push view was average 4.4mm at the last follow up. There were 17 cases(44%) of unfavorable results which showed unstable posterior displacement more than 4mm compared with the uninjured knee in push view. Among the 19 cases of arthroscopic second look examinations, nearly normal PCL appearances of the grafted tendons were noted only in 9 cases(47%). In group B : The $M{\ddot{u}}ller$'s knee score was average 86.7 points, the posterior displacemnet in push view was average 3.6mm at the last follow up. There were 5 cases(23.8%) of unfavorable results which showed unstable posterior displacement more than 4mm compared with the uninjured knee in push view but 4 out of 5 cases showed 6mm posterior displacement in push views. Among the 7 cases of arthroscopic second-look examinations, 6 cases(86%) showed nearly normal PCL appearances of the grafted tendons. In modified tibial inlay technique of PCL reconstruction, it was easier to pull out the BPTB and in cases of remained laxed meniscofemoral ligament it was easier to preserve the remained structures than transtibial two tunnel technique. We expect the "modified tibial inlay technique" may solve the problem of grafted patellar tendon abrasion at the posterior orifice of tibial tunnel and may contribute to the successful PCL reconstruction.

• Journal of Korea Multimedia Society
• /
• v.24 no.6
• /
• pp.805-814
• /
• 2021

Push-ups are one of the body exercises that can be easily measured anytime, anywhere. As one of the most widely used techniques as a test tool for evaluating physical strength, they are broadly used in various fields, especially in fields that require physical ability to estimate, such as military, police, and firefighters. However, social distancing is currently being implemented, and the issue of fairness has been steadily raised due to subtle differences between measurement. Accordingly, in this paper, the correct posture for each individual was photographed and learned by a high-performance computer, and the result was derived by comparing it with the case of performing the incorrect posture of the individual. If method is introduced into the physical fitness evaluation through the proposed method, the individual takes the correct posture and learns the photographed photo, and measures the posture with several images taken during a given time. Through this, it is possible to measure more objectively because it measures with the merit that can be measured even in the present situation and with one's correct posture.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.708-712
• /
• 2001

A new phase-shifted parallel-input/series-output (PI SO) dual inductor-fed push-pull converter for high-power step­up applications is proposed. This converter is operated at a constant duty cycle and employs an auxiliary circuit to control the output voltage with a phase-shift between the two modules. It features a voltage conversion characteristic which is linear to changes in the control input, and high step-up ratio with a greatly reduced switch turn-off stress resulting in a significant increase in the converter efficiency. It also shows a low ripple content and low root-mean-square (RMS) current in the output capacitor. The operational principle is analyzed and a comparative analysis with the conventional pulse-width-modulated (PWM) PISO dual inductor-fed push-pull converter is presented. A 50kHz, 800W, 350Vdc prototype with an input of 20-32Vdc has also been constructed to validate the proposed converter. The proposed converter compares favorably with the conventional counterpart and is considered well suited to high-power step-up applications.