• PNF and Movement
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• v.18 no.1
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• pp.127-132
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• 2020

Purpose: This study aimed to investigate the impact of resistance on the muscle activities of the long and short heads of the biceps brachii, according to the elbow angle in supination, and the difference in muscle activity between the long and the short heads. Methods: This study was conducted with 22 men in their 20s who voluntarily agreed to participate. With the glenohumeral joint neutral in a position of supination, the elbow angle was randomly moved to 0°, 30°, 60°, and 90°. Using an 8-channel surface EMG while the participants held a 2-kg. dumbbell, the muscle activities of the long and the short heads of the biceps brachii were measured. The measured data were statistically processed using SPSS for Windows 12.0. For the activities of the short and the long heads according to the angle, a one-way ANOVA was conducted, and subsequently, to check the results of an analysis of the difference between groups, an LSD post-hoc test was conducted. An independent t-test was used to compare the activities of the long head and the short head according to the angles. Results: The analysis of the impact of the load of the dumbbell at each elbow angle on the muscle activities of the long and short heads of the biceps brachii revealed significant differences in both heads (p < 0.05). The result of the post-hoc analysis showed significant differences in both heads at angles between 0° and 30°, between 0° and 60°, and between 0° and 90°. Analysis of the impact of the load of the dumbbell in supination on the muscle activities of the long and short heads showed a significant difference at the angle between 0° and 30° (p < 0.05). Conclusion: The long head of the biceps brachii mainly acts in supination; however, in supination at elbow-bending angles of 60° and 90°, there was no difference in muscle activity between the short head and the long head.

• PNF and Movement
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• v.19 no.1
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• pp.147-152
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• 2021

Purpose: This study was conducted to investigate the functional differences of the two heads of the biceps brachii by measuring the functions in supination according to pronation by the angle of the flexion of the elbow joint, except for the activities of the elbow flexors. Methods: This study was conducted with 25 healthy men in their 20s. At a glenohumeral-joint 0˚ flexion posture, angles of flexion of the elbow joint of 0˚, 30˚, 60˚, 90˚, and 120˚ were randomly provided, and they were asked to perform supination and pronation with an elastic band. Using an eight-channel surface electromyogram, the muscle activities of the long and short heads of the biceps brachii were measured. The activities of the short and long heads according to the angle were analyzed using a one-way ANOVA, and as a post-test, LSD was employed. Results: The analysis of the impact of the resistance of the elastic band in supination on the differences in the muscle activities in the short and long heads suggests there was a significant difference between 0˚ and 30˚ (p < 0.05). Conclusion: In supination according to forearm pronation, the long head had greater action in the early flexion posture of the elbow joint, and it is judged that the ratio of the flexion of the elbow joint according to the actions of the biceps brachii was considered small.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2006.03a
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• pp.76-77
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• 2006

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2002.10a
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• pp.101-101
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• 2002

• Physical Therapy Korea
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• v.18 no.1
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• pp.28-36
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• 2011

The aim of this study was to compare electromyography activity for long and lateral heads of triceps brachii muscle according to forearm positions during different triceps strengthening exercises. The muscle activities for long and lateral head of triceps brachii were measured by surface electromyography. Fifteen healthy volunteers participated for this study and performed elbow extension in three different elbow extension exercises (elbow extension in a supine position; EES, elbow extension with shoulder abduction at 90 degrees in a prone position; EESA, and elbow extension with one arm at the side of the trunk in a prone position; EESP) and forearm positions (supination, neutral, and pronation). A two-way repeated measures ANOVA was used to compare the effects of the exercise positions and forearm positions. The EMG activities of the long head of the triceps brachii increased significantly during EESP with forearm supination, whereas the activity of the lateral head of the triceps brachii increased significantly during EESA with the forearm in a neutral position (p<.05). The results of this study suggest that exercise positions and forearm positions should be considered for selectively strengthening the long and lateral heads of triceps brachii muscles.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2004.03a
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• pp.59-66
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• 2004

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2002.03a
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• pp.119-120
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• 2002

• The Academic Congress of Korean Shoulder and Elbow Society
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• 1998.03a
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• pp.9-12
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• 1998

• PNF and Movement
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• v.21 no.1
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• pp.47-52
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• 2023

Purpose: This study aims to examine the functional difference in the long and short heads of the biceps brachii by investigating the onset time of muscle contractions in the biceps brachii in the supination motion according to whether the flexor of the elbow joint is excluded. Methods: This study was conducted with 21 healthy men aged in their 20s. While performing forearm pronation at an elbow flexion angle of 90 degrees, the onset time of muscle contractions in the long and short heads of the biceps brachii was measured and compared in a posture where the humerus is placed on a table and the posture is lifted against gravity. Using an independent samples t-test, the difference in the onset time of muscle contractions in the long and short heads of the biceps brachii was analyzed. Results: The onset time of the long head was shorter if the flexor activity of the elbow joint was excluded, while that of the short head of the biceps brachii was shorter if it was not excluded. Conclusion: It is noted that the long head of the biceps brachii mainly functions as a supinator muscle, while the short head of the biceps brachii plays a role in stabilizing and maintaining flexion of the elbow joint.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.11
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• pp.1613-1621
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• 2002

An electromagnetic flowmeter(EMF) essentially averages the velocity distribution over the pipe cross- sectional area, and the measured value is dependent on the velocity profiles. In this study, installation effects of 90$^{\circ}$long elbow(KS B 1522, ISO 3419) on the EMF characteristics was investigated. A commercial EMF was adopted and the distribution of magnetic field in the electrodes cross section was measured. In the experiment, the national flow standard system, of which measurement uncertainty was evaluated in accordance with ISO 17025 recommendation, was used fur characterization of EMF. The leading line has 150D long straight pipe to established a fully developed flow before entering into the elbow and the elbow was installed downstream of it. then the flowmeter was tested within 50 D from the elbow. The installation effects of the flowmeter were investigated by varying the mean velocity(Reynolds No.)in pipe section, the locations and the direction of electrodes plane.($\phi$) From the experimental results, we find the optimal conditions to get most accurate measurements. Generally, the deviations from the calibration value were less than 0.5 % in farther than 10D distance from the elbow and the direction of electrode plane. $\phi$ = 90$^{\circ}$yielded the smallest measurement deviation. These characteristics were shown consistently in turbulent region regardless of the mean Reynolds number.