• Journal of the Korean Society of Physical Medicine
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• v.4 no.4
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• pp.269-274
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• 2009

Purpose：The purpose of this study is an interval palmar width according to change of muscle activation under push-up movement. Methods：Three, this study participation normal young adult (male 3, mean age ; 24yaers). The subject performed maximum contraction under push-up movement. EMG activaty patterns is measured with three different width. The EMG activity of pectoralis major and latissimus dorsi were measured using surface electromyography. Results：EMG activation of pectoralis major and latissimus dorsi following of push-up was shown significant difference(p<.05). Also, experiment value was agree with calculation value and width of shoulder position was minimum of pectoralis major and latissimus dorsi muscle activity. Conslusion：RMS values in case of fretum and wide width of the hands on Latissimus Dorsi are shown muscle activity $132{\mu}V$ and $173.5{\mu}V$, respectively. Especialy, RMS value in terms of wide width of the hands on muscles is shown very enhanced muscle activity. It is suggest that interval palmar width of the hands on pectoralis major and latissimus dorsi in push-up movement was effective to intensify of the muscle activity.

• Physical Therapy Korea
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• v.18 no.1
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• pp.1-8
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• 2011

Push-up plus has been advocated for increasing the activity of the serratus anterior muscle, the most critical scapular stabilizer. However, no previous study has reported the possibility of compensatory motion on the part of the pectoralis major, which could substitute for the action of the serratus anterior during push-up plus. The aim of the current study was to investigate the immediate effect of electromyography (EMG) biofeedback of the pectoralis major muscle on the pectoralis major, upper trapezius, and serratus anterior muscles during push-up plus. Fourteen healthy young subjects voluntarily participated in this study; each subject performed push-up plus from the quadruped position, in two conditions (i.e., with or without visual and auditory biofeedback). Surface EMG was used to measure pectoralis major, serratus anterior, and upper trapezius activity. A paired t-test was used to determine any statistically significant difference between the two conditions. Additionally, effect size was calculated to quantify the magnitude of EMG biofeedback in each muscle. Visual and auditory feedback reduced pectoralis major muscle activity significantly (p=.000) and increased the serratus anterior muscle activity significantly (p=.002), but did not induce a significant difference in upper trapezius muscle activity (p=.881). Thus, it is concluded that the visual and auditory feedback of pectoralis major muscle activity can be used to facilitate serratus anterior muscle activity during push-up plus.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.111-116
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• 2018

The aim of this study was to determine the effects of tote bag weight on muscle thickness of pectroalis minor and tone of upper trapezius in young adult women. 27 women habitual of carrying tote bags. The subjects were measured the tone of the upper trapezius muscle and the thickness of the pectoralis minor muscle while carrying tote bags with the weight of 0%, 5%, 7.5% and 10% of the subjects' body weight. As the weight load increased, the upper trapezius muscle demonstrated significantly increased muscle tone (p<.05). additionally, a significantly increased thickness in the pectoralis minor muscle was noted(p<.05). These findings suggest that the habit of carrying a tote bag on the wrist may be disadvantageous to improving the two muscles in young women. Therefore, this study recommend women who likely used tote bag decrease the weight of the bag.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.940-947
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• 2018

The purpose of this study was to obtain data to support applied motions of bench press and to provide basic data for the efficient execution of the exercise by analyzing muscular activation through measuring electromyogram of pectoralis major and erector spinae when flat bench pressing with feet on the ground versus feet on the bench. For this study, 4 amateur bodybuilders and 2 health trainers were chosen as subjects. Surface electrodes were attached on the measuring muscles; pectoralis major and erector spinae. Motion phases were defined for the flat bench press and each subject, with a 10RM load, performed a set with feet on the ground and another set with feet on the bench. Data was analyzed in SPSS 20.0 and the following results were obtained. The placement of the feet did not affect the muscular activation of the pectoralis major during the flat bench press. however, the muscular activation of the erector spinae was different between the two positions.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.421-427
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• 2005

Although the incidence of mediastinal wound infection in patient undergoing median sternotomy for cardiovascular surgery is relatively low(less than 1%), it is not only a devastating and potentially life-threatening complication but also associated morbidity, mortality and cost are unacceptably high. During the past few decades various methods had been applied for the treatment of postoperative mediastinitis. Currently, chest wall reconstruction by using muscle flaps-especially pectoralis major muscle and rectus abdominis muscle are commonly selected for the reconstruction after wide debridement has become widely accepted. We performed bilateral pectoralis major-rectus abdominis muscles in-continuity bipedicle flap to overcome the limit of each flap for reconstruction of sternal defects in 17 patients. We analyzed the results of the surgery. Recurrent infection developed in 17.6% of cases and abdominal herniation was observed in one patient. There was no postoperative hematoma or death. We conclude that this flap is very valuable in reconstruction of the anterior chest wall defect caused by post-sternotomy infection because it provides sufficient volume to fill the entire mediastinum, and the complication rate compares favorably to that of other methods.

• Physical Therapy Korea
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• v.24 no.2
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• pp.48-57
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• 2017

Background: Rounded shoulder posture (RSP), a postural abnormality, might cause shoulder pain and pathologic conditions. Although most previous research has investigated RSP focusing on the proximal structures of the shoulder, such as the scapula and pectoralis muscles, the relationship between RSP and anterior distal structures of the upper extremity, such as the biceps brachii muscle and elbow joint, is not clearly understood. Objects: This study aimed to investigate the correlations between RSP and the biceps brachii length, elbow joint angle (EJA), pectoralis minor length, general pectoralis major length, humeral head anterior translation (HHAT), glenohumeral internal rotation (IR), external rotation (ER), and horizontal adduction (HAD). Methods: Twelve subjects with RSP (6 male, 6 female) were recruited. All subjects fulfilled the RSP criteria indicated by a distance ${\geq}2.5cm$ from the posterior aspect of the acromion to the table in the supine position. The examiner measured each of the following parameters twice: RSP, biceps brachii length, EJA, pectoralis minor length, pectoralis major length, HHAT, glenohumeral IR, ER, and HAD. Pearson's correlation coefficient(r) was used to assess the correlation between RSP and all the variables. Results: There was a significant moderate positive correlation between RSP and biceps brachii length (r=.55, p=.032), moderate negative correlation between RSP and pectoralis minor length (r=-.62, p=.015), and moderate positive correlation between RSP and HHAT (r=.53, p=.038). Conclusion: The biceps brachii length, pectoralis minor length, and HHAT could be used to evaluate patients with RSP. Better understanding of the correlation between these factors and RSP could help in the development of effective methods to treat patients with this condition in clinical management.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.646-652
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• 2015

The beef forequarter muscle comprises approximately 52% of carcass weight. The objective of this study was to evaluate the physiochemical characteristics and meat color from forequarter muscle of Holstein steers. Fifteen forequarter muscles were trimmed of external connective tissue and fat. An experimental group of eight Holstein steers was assessed using meat color, water-holding capacity, drip loss, and Warner-Bratzler shear force value at the same quality grade. The M. omotransversarius (0.45 kg) had the highest (p<0.05) lightness (L*) value, whereas the M. teres major (0.4 kg) and M. triceps brachii (caput laterale) (0.52 kg) had the lowest (p<0.05) values. The M. semispanitus capitus (1.48 kg), which is a neck muscle, had the highest values for both redness (a*) and yellowness (b*), whereas the lowest (p<0.05) values were for the M. teres major. The M. omotransversarius, M. latissimus dorsi (1.68 kg), and M. rhomboideus (1.2 kg) were ranked high (p<0.05) in water-holding capacity. The drip loss value was the highest for the M. longissimus dorsi thoracis (p<0.05; 1.86 kg), while the M. infraspinatus (2.28 kg), M. supraspinatus (1.38 kg), M. brachiocephalicus (1.01 kg), and M. pectoralis superficialis (1.18 kg) had the lowest (p<0.05). The Warner-Bratzler shear force value indicated that the M. pectoralis profundus (3.39 kg), M. omotransversarius, and M. brachiocephalicus were the toughest (p<0.05), whereas the M. subscapularis (0.86 kg), M. longissimus dorsi thoracis, M. teres major, and M. infraspinatus were the most tender cuts (p<0.05). Here, muscle type explained most of the variability in the forequarter physiochemical characteristics. Thus, our findings suggest that these muscle profile data will allow for more informed decisions when selecting individual muscles to produce value-added products from Holstein steers.

• Korean Journal of Applied Biomechanics
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• v.32 no.1
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• pp.31-36
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• 2022

Objective: The purpose of this study was to investigate muscle activation according to the four strap lengths in the TRX plank exercise to provide scientific and accurate data on effective training methods. Method: Twenty healthy men who had at least 6 months of weight training experience and could fully adjusted plank exercise, were participate in this study (age: 25.2 ± 3.7 yrs., height: 174.2 ± 3.9 cm., weight: 71.2 ± 9 kg). To pursue the study purpose, surface electrodes were attached to trunk muscles (pectoralis major, rectus abdominis, external oblique, internal oblique, erector spinae, latissimus dorsi) and lower extramity muscles (gluteus maximus, rectus femoris, gastrocnemius), and the muscle activity was measured using 11-channel electromyography equipment. In order to verify the muscle activation according to the four strap lengths during TRX plank exercise, an one-way ANOVA with repeated measure was used with statistical significance level set at as α=.05. Results: First, there were statistically significant differences in pectoralis major, rectus abdominis, external oblique, internal oblique, and erector spinae among TRX strap lengths. Second, there were statistically significant differences in gluteus maximus, rectus femoris, and gastrocnemius among TRX strap lengths. Third, even though no statistically significant difference found in latissimus dorsi, but increased muscle activation tendency was showed as the length of the strap increased. Conclusion: From the results of this study, it may be possible that TRX exercise prevent injuries and improve lower extremity muscle as well as trunk muscles by setting appropriate length of strap.

• Physical Therapy Korea
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• v.30 no.2
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• pp.160-168
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• 2023

Background: Individuals with scapular winging have a weak serratus anterior (SA) muscle, and to compensate, the pectoralis major (PM) and upper trapezius (UT) muscles excessively activate, which can cause upper extremity dysfunction. This study aimed to compare the effects of isometric horizontal abduction (IHA) on SA, PM, and UT muscle activity, as well as the SA/PM and SA/UT muscle activity ratios during knee push-up plus (KPP) at 90° and 120° of shoulder flexion. Objects: This study aimed to compare the effects of IHA on SA, PM, and UT muscle activity, as well as the SA/PM and SA/UT muscle activity ratios during KPP at 90° and 120° of shoulder flexion. Methods: This study, conducted at a university research laboratory, included 20 individuals with scapular winging. Participants performed KPP with and without IHA at 90° (KPP90) and 120° (KPP120) of shoulder flexion. SA, PM, and UT muscle activity were measured using surface electromyography. Results: PM activity in KPP90 with IHA was significantly lower than KPP90 and in KPP120 was significantly lower than KPP90. UT activity was significantly greater with IHA than without IHA and at 120° than 90° of shoulder flexion. SA/PM muscle activity ratio was significantly higher in KPP90 with IHA than without IHA and in KPP120 than in KPP90. SA/UT muscle activity ratio was significantly lower with IHA than without IHA. Conclusion: KPP90 with IHA and KPP120 are effective exercises to reduce PM activity and increase SA/PM muscle activity ratio. However, applying IHA in KPP90 also reduces SA/UT muscle activity ratio, implying that it would be preferable to apply KPP120 in individuals overusing their UT muscles.

• Journal of the Korean Society of Safety
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• v.16 no.1
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• pp.79-83
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• 2001

Posture of the upper limbs in field works is known to be an important risk factor associated with CTD(Cumulative Trauma Disorders). In particular, uncomfortable posture and highly repetitive works in shipbuilding industry(for instance, sand blasting, grinding and blast painting, etc) made workers exposed to a great risk of injuries. The purpose of this paper is to analyze recruitment pattern of the muscles according to posture(joint angle displacement) during grinding. In this study, EMG signals of pectoralis major, latissimus dorsi, and posterior deltoid muscle were measured and analyzed from FlexComp EMG solution. And subjective ratings of perceived exertion were made using Borg's CR-10 rating scale.