• Physical Therapy Korea
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• v.26 no.3
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• pp.91-98
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• 2019

Background: The bridge exercise targets the gluteus maximus (Gmax) and gluteus medius (Gmed). However, there is also a risk of dominant hamstring (HAM) and erector spinae (ES) muscles. Objects: To analyze the muscle activity the of Gmax, Gmed, HAM and ES during the bridge exercise with and without hip external rotation in different degrees of knee flexion. Methods: Twenty-three subjects were participated. The electormyography (EMG) activity of the Gmax, Gmed, HAM and ES muscles was recorded during the exercise. The subjects performed the bridge exercise under four different conditions: (a) with $90^{\circ}$ knee flexion, without hip external rotation (b) with $90^{\circ}$ knee flexion, with hip external rotation (c) with $135^{\circ}$ knee flexion, without hip external rotation (d) with $135^{\circ}$ knee flexion, with hip external rotation. Results: There was no significant interaction effect between the degree of knee flexion and hip external rotation. There was a significant main effect for degree of knee flexion in Gmax, HAM muscles activity. Gmax muscle activity was significantly greater in the $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p<.001). While HAM muscle activity was significantly less in $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p<.001). ES muscle activity was significantly less in the $135^{\circ}$ knee flexion position than in the $90^{\circ}$ knee flexion position (p=.002). The activity of both the Gmax and Gmed muscles was significantly greater with hip external rotation (p<.001 and p=.005, respectively). Conclusion: For patients performing the bridge exercise, positioning the knee in $135^{\circ}$ of flexion with hip external rotation is effective for improving Gmax and Gmed muscle activity while decreasing HAM, and ES muscle activity.

• Physical Therapy Korea
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• v.29 no.1
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• pp.64-69
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• 2022

Background: Gluteus medius muscle is important for the stability of hip joint. The sufficient core stability can be contributed to the performance of gluteus medius muscle in standing position. In addition, the external support may affect core stability in standing position. Objects: The purpose of this study was to investigated the effectiveness of the external support on the strength and muscle activity of hip abductor muscle during hip abduction in standing position in subjects without core stability. Methods: Fifteen subjects participated in this study. The subjects were evaluated by using the double-leg lowering with bent knees to measure the core stability. The strength and muscle activity of hip abductors was measured in standing position with the condition with and without external support using the tensiometer sensor and the surface electromyography. The paired t-test was used to investigate the difference between hip abductor strength and activity according to external support. The level of statistical significance was set at α = 0.05. Results: The hip abductor strength and muscle activity of gluteus medius muscle with external support were significantly greater than those without external support during hip abduction in standing position (p < 0.05). Conclusion: During hip abduction in standing position, the external support may be contributed to the improvement of the hip abductor strength and muscle activity of gluteus medius especially in the subjects without core stability.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.2
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• pp.23-29
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• 2023

Background: There is still controversy as to whether hip external rotation and dorsiflexion selectively activate the vastus medialis obliquus (VMO) during straight leg raise exercise. Due to the anatomical characteristics, hip adduction must be preceded to activate the VMO. In this study, the activities of the rectus femoris (RF), vastus lateralis (VL), VMO were measured by adding the hip adduction movement to the straight leg raise exercise with hip 45° external rotation and straight leg raise exercise with hip 45° external rotation and dorsiflexion. Through this, we want to find out whether the VMO is selectively activated. Methods: Thirteen healthy participants performed straight leg raise exercise with hip 45° external rotation, straight leg raise exercise with hip 45° external rotation and dorsiflexion, straight leg raise exercise with hip 45° external rotation and adduction, straight leg raise exercise with hip 45° external rotation and adduction and dorsiflexion was randomly performed. Through this, EMG data of the RF, VL, VMO were collected. Results: During the straight leg raise exercise, hip adduction increased the activity of the VMO and VL, no significant difference was found(p>.05). However, in the VMO/VL ratio, straight leg raise exercise with hip 45° external rotation and adduction and dorsiflexion activated the VMO and the VL at a ratio of about 1:1, It showed a significantly higher rate than straight leg raise exercise with hip 45° external rotation(p<.05). Conclusion: During the straight leg raise exercise, hip adduction is considered to be an important movement that can selectively induce the activity of the VMO. Therefore, follow-up studies on this should be conducted.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.39-46
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• 2007

The purpose of this study was to develop a comprehensive posture classification scheme considering the effects of external load and motion repetition as well as those of working posture. The scheme was developed based on a series of existing empirical studies dealing with postural classification scheme, effects of external load and motion repetition. Ranges of joint motions, external load and motion repetition were divided into the groups with the same degree of discomforts. Each group was assigned a numerical relative discomfort score of code on the basis of discomfort values for the neutral position of elbow flexion. The criteria for evaluating stress of working postures were proposed based on the four distinct action categories, in order to enable practitioners to apply appropriate corrective actions. The proposed scheme was compared with OWAS, RULA and REBA. The comparison revealed that while the proposed scheme and RULA showed similar results for the working postures with light external load and non-repetitive postures, the former overestimated postural load for postures with moderate or heavy external load and repetitive postures than the latter.

• Physical Therapy Rehabilitation Science
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• v.1 no.1
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• pp.13-16
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• 2012

Objective: Electroencephalogram (EGG)-feedback is a training procedure aimed at altering brain activity, and is used as a treatment for disorders like attention. The purpose of this study was to determine the effects of external focus of attention by EGG-feedback on balance in young adults. Design: Cross-sectional study. Methods: Subject were students in Sahmyook University. Fifty young adults in their twenties and thirties. Subjects were performed both with and without external focus of attention by EEG-feedback on the posture of standing and tandem standing. Participants were educated effort to maintain static posture when they were under internal focus of attention. Good Balance System was used for measurement of postural consistency upon the following force platforms. Results: Body sway decreased significantly both normal standing and tandem standing with external focus of attention by EEG-feedback (p<0.05). Conclusions: The results demonstrate that the benefits of an external attentional focus are generalizable to young adults. The external focus of attention outperformed the internal focus of attention on the postural balance (p<0.05). It is showed that external focus of attention significant effects on balance by revoked automatic postural control of movement. Furthermore balance might be improved by training with an external focus. Further study is required to develop for training as a method of preventing fall in elderly peoples.

• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.9-15
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• 2005

The purpose of this study is to quantitatively investigate perceived discomfort of complex shoulder postures with external loads and to propose a preliminary evaluation scheme of shoulder postures. Twelve healthy male adults participated in an experiment to rate their perceived discomfort of shoulder postures. The independent variables were shoulder flexion angle(45, 90 and 150$^{\circ}$), adduction/abduction angle(-30, -10, 0, 30 and 60$^{\circ}$), and external load(0, 1.5 and 3.0kg). The results revealed that the flexion angle, external load and their interaction significantly affected the perceived discomfort(p$<$0.05) but the effect of adduction/abduction angle on the discomfort was not significant(p$>$0.05). The effect of external load was much larger than that of any other factor with explaining about 81% of the total variation of discomfort scores. Based on the experimental results a preliminary scheme was presented to evaluate the stress of shoulder postures with external loads.

• Physical Therapy Korea
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• v.25 no.2
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• pp.71-77
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• 2018

Background: There are insufficient objective or quantitative evidence for the better intervention to improve proprioception particularly for the application of external load. There are conflicting opinions whether the external load is effective for proprioception improvement or not. Objects: The purpose of this study was to investigate effects of external load on proprioception of shoulder joint quantitatively using 3D motion capture system. Methods: Nine healthy adults joined for this study. They were asked to perform scapular plane abduction motion with attaching reflective markers on the trunk and upper limb. The 3D positions of finger marker, while they performed the same task with and without external load, were recorded and analyzed. Results: All participants showed decreased variable errors in the vertical direction when the external load was applied (p<.02). Even though other directions (y, z) and absolute errors increased, they did not have statistical significances. Conclusion: Based on this study results, the external load application would be effective for shoulder joint position sense improvement.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.127-132
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• 2001

An experimental study on penetration integrity of the reactor vessel has been performed under external vessel cooling during a core melt accident. In this study a series of experiments are performed for the verification of the effects of coolant in the annulus between the ICI(In-Core Instrumentation) nozzle and the thimble tube and also the effects of external vessel cooling on the integrity of the penetration using the test section including only one penetration and $Al_{2}O_{3}$ melt as a corium simulant. The experimental results have shown that penetration is more damaged in the case of no external vessel cooling compared with the case of external vessel cooling. It is preliminarily concluded that the external vessel cooling is very effective measure for the improvement of the penetration integrity. Also it is confirmed from the experimental results that the coolant in the annulus reduces the melt penetration distance through the annulus and enhance the integrity of the reactor vessel penetration in the end.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.102-111
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• 2008

Background : The purpose of this study is to make the oriental medicine treatment useful and develop the way of acne cure. Object&Metbod : This study is based on analysis of Recent paper about Oriental medicine of acne, mainly for the external treatment. Results: We analyzed recent treatis about acne cure with external treatment in clinical and analytic study. For the first, there are various clinical approaches with: single use of external treatment, external treatment and herb medicine methods and acidic ionized water. The others are about practical applications on the external treatment, and traditional chinese medical approaches. Conclusion: To develop the better medical care on acne, development and verifications of various treatment methods are necessary on the basis of the merits of oriental treatment.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.2
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• pp.80-93
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• 2008

Objective : The purpose of this study is to investigate the results of preceding research related external treatment for Atopic dermatitis(AD). Methods : We studied the 13 research papers that had been published in The Journal of Korean Oriental Medical Ophthalmology & Otolaryngology & Dermatology, The Journal of Korean Oriental Pediatrics, The Journal of Korean Oriental Internal Medicine, The Journal of Korean Oriental Medicine, Korean Journal of Oriental Physiology & Pathology and so on. Results : About 13 treatises, 3 treatises were for the literatual study, I treatise was for the clinical research about the effects of external therapy, 3 treatises were for the effects of herbal medicine along with external treatment on AD development in NC/Nga mice, 6 treatises were for the case of AD. Conclusion : These treatises showed that external treatment is effective method to improve AD. To develop the better external treatment on AD, we have need of studies on the well used prescriptions and herbs through double-blind, randomized, placebo-controlled methods, clinic research and so on.